Bump to v5.6.4

remove lru-redux

.github/probots.yml

@@ -1,2 +0,0 @@
-enabled:
-  - cla

.github/workflows/cla.yml

@@ -0,0 +1,22 @@
+name: Contributor License Agreement (CLA)
+
+on:
+  pull_request_target:
+    types: [opened, synchronize]
+  issue_comment:
+    types: [created]
+
+jobs:
+  cla:
+    runs-on: ubuntu-latest
+    if: |
+      (github.event.issue.pull_request 
+        && !github.event.issue.pull_request.merged_at
+        && contains(github.event.comment.body, 'signed')
+      ) 
+      || (github.event.pull_request && !github.event.pull_request.merged)
+    steps:
+      - uses: Shopify/shopify-cla-action@v1
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          cla-token: ${{ secrets.CLA_TOKEN }}

.github/workflows/liquid.yml

@@ -1,40 +1,37 @@
 name: Liquid
 on: [push, pull_request]
+
+env:
+  BUNDLE_JOBS: 4
+  BUNDLE_RETRY: 3
+
 jobs:
   test:
     runs-on: ubuntu-latest
     strategy:
       matrix:
         entry:
-          - { ruby: 2.5, allowed-failure: false }
-          - { ruby: 2.6, allowed-failure: false }
-          - { ruby: 2.7, allowed-failure: false }
-          - { ruby: ruby-head, allowed-failure: true }
-    name: test (${{ matrix.entry.ruby }})
+          - { ruby: 3.0, allowed-failure: false } # minimum supported
+          - { ruby: 3.2, allowed-failure: false }
+          - { ruby: 3.3, allowed-failure: false }
+          - { ruby: "3.4.0-rc1", allowed-failure: false } # latest
+          - { ruby: ruby-head, allowed-failure: false }
+    name: Test Ruby ${{ matrix.entry.ruby }}
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.entry.ruby }}
-      - uses: actions/cache@v1
-        with:
-          path: vendor/bundle
-          key: ${{ runner.os }}-gems-${{ hashFiles('Gemfile') }}
-          restore-keys: ${{ runner.os }}-gems-
-      - run: bundle install --jobs=3 --retry=3 --path=vendor/bundle
+          bundler-cache: true
+          bundler: latest
       - run: bundle exec rake
         continue-on-error: ${{ matrix.entry.allowed-failure }}
+
   memory_profile:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: 2.7
-      - uses: actions/cache@v1
-        with:
-          path: vendor/bundle
-          key: ${{ runner.os }}-gems-${{ hashFiles('Gemfile') }}
-          restore-keys: ${{ runner.os }}-gems-
-      - run: bundle install --jobs=3 --retry=3 --path=vendor/bundle
+          bundler-cache: true
       - run: bundle exec rake memory_profile:run

.gitignore

@@ -4,7 +4,6 @@
 pkg
 *.rbc
 .rvmrc
-.ruby-version
-Gemfile.lock
 .bundle
 .byebug_history
+Gemfile.lock

.rubocop.yml

@@ -1,5 +1,7 @@
+inherit_gem:
+  rubocop-shopify: rubocop.yml
+
 inherit_from:
-  - 'https://shopify.github.io/ruby-style-guide/rubocop.yml'
   - .rubocop_todo.yml
 
 require: rubocop-performance
@@ -8,11 +10,19 @@ Performance:
   Enabled: true
 
 AllCops:
-  TargetRubyVersion: 2.4
   NewCops: disable
+  SuggestExtensions: false
   Exclude:
     - 'vendor/bundle/**/*'
 
 Naming/MethodName:
   Exclude:
     - 'example/server/liquid_servlet.rb'
+
+Style/ClassMethodsDefinitions:
+  Enabled: false
+
+# liquid filter calls were being mistaken to be calls on arrays
+Style/ConcatArrayLiterals:
+  Exclude:
+    - 'test/integration/standard_filter_test.rb'

.rubocop_todo.yml

@@ -1,27 +1,74 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2020-12-11 18:53:41 UTC using RuboCop version 1.6.1.
+# on 2022-05-18 19:25:47 UTC using RuboCop version 1.29.1.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
 # versions of RuboCop, may require this file to be generated again.
 
-# Offense count: 2
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle.
-# SupportedStyles: runtime_error, standard_error
-Lint/InheritException:
+# Offense count: 1
+# This cop supports safe auto-correction (--auto-correct).
+# Configuration parameters: TreatCommentsAsGroupSeparators, ConsiderPunctuation, Include.
+# Include: **/*.gemspec
+Gemspec/OrderedDependencies:
   Exclude:
-    - 'lib/liquid/interrupts.rb'
+    - 'liquid.gemspec'
 
-# Offense count: 113
-# Cop supports --auto-correct.
-# Configuration parameters: AutoCorrect, AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
-# URISchemes: http, https
-Layout/LineLength:
-  Max: 260
+# Offense count: 6
+# This cop supports safe auto-correction (--auto-correct).
+Layout/ClosingHeredocIndentation:
+  Exclude:
+    - 'test/integration/tags/for_tag_test.rb'
+
+# Offense count: 34
+# This cop supports safe auto-correction (--auto-correct).
+Layout/EmptyLineAfterGuardClause:
+  Exclude:
+    - 'lib/liquid/block.rb'
+    - 'lib/liquid/block_body.rb'
+    - 'lib/liquid/context.rb'
+    - 'lib/liquid/drop.rb'
+    - 'lib/liquid/lexer.rb'
+    - 'lib/liquid/parser.rb'
+    - 'lib/liquid/profiler/hooks.rb'
+    - 'lib/liquid/standardfilters.rb'
+    - 'lib/liquid/tags/for.rb'
+    - 'lib/liquid/tags/if.rb'
+    - 'lib/liquid/utils.rb'
+    - 'lib/liquid/variable.rb'
+    - 'lib/liquid/variable_lookup.rb'
+    - 'performance/shopify/money_filter.rb'
+    - 'performance/shopify/paginate.rb'
 
 # Offense count: 8
+# This cop supports safe auto-correction (--auto-correct).
+# Configuration parameters: AllowAliasSyntax, AllowedMethods.
+# AllowedMethods: alias_method, public, protected, private
+Layout/EmptyLinesAroundAttributeAccessor:
+  Exclude:
+    - 'lib/liquid/template.rb'
+    - 'test/integration/filter_test.rb'
+    - 'test/integration/tags/include_tag_test.rb'
+    - 'test/unit/strainer_template_unit_test.rb'
+
+# Offense count: 17
+# This cop supports safe auto-correction (--auto-correct).
+# Configuration parameters: EnforcedStyle, IndentationWidth.
+# SupportedStyles: aligned, indented
+Layout/LineEndStringConcatenationIndentation:
+  Exclude:
+    - 'test/integration/tags/for_tag_test.rb'
+    - 'test/integration/tags/increment_tag_test.rb'
+
+# Offense count: 1
+# This cop supports safe auto-correction (--auto-correct).
+# Configuration parameters: EnforcedStyle, IndentationWidth.
+# SupportedStyles: aligned, indented
+Layout/MultilineOperationIndentation:
+  Exclude:
+    - 'lib/liquid/expression.rb'
+
+# Offense count: 9
 Lint/MissingSuper:
   Exclude:
     - 'lib/liquid/forloop_drop.rb'
@@ -33,7 +80,7 @@ Lint/MissingSuper:
     - 'test/integration/tags/for_tag_test.rb'
     - 'test/integration/tags/table_row_test.rb'
 
-# Offense count: 43
+# Offense count: 44
 Naming/ConstantName:
   Exclude:
     - 'lib/liquid.rb'
@@ -51,7 +98,83 @@ Naming/ConstantName:
     - 'performance/shopify/paginate.rb'
     - 'test/integration/tags/include_tag_test.rb'
 
+# Offense count: 9
+# Configuration parameters: CheckIdentifiers, CheckConstants, CheckVariables, CheckStrings, CheckSymbols, CheckComments, CheckFilepaths, FlaggedTerms.
+Naming/InclusiveLanguage:
+  Exclude:
+    - 'lib/liquid/drop.rb'
+    - 'lib/liquid/parse_context.rb'
+    - 'test/integration/drop_test.rb'
+    - 'test/integration/tags/if_else_tag_test.rb'
+
 # Offense count: 2
 Style/ClassVars:
   Exclude:
     - 'lib/liquid/condition.rb'
+
+# Offense count: 3
+# This cop supports safe auto-correction (--auto-correct).
+Style/ExplicitBlockArgument:
+  Exclude:
+    - 'test/integration/context_test.rb'
+    - 'test/integration/tag/disableable_test.rb'
+    - 'test/integration/tags/for_tag_test.rb'
+
+# Offense count: 2982
+# This cop supports safe auto-correction (--auto-correct).
+# Configuration parameters: EnforcedStyle, ConsistentQuotesInMultiline.
+# SupportedStyles: single_quotes, double_quotes
+Style/StringLiterals:
+  Enabled: false
+
+# Offense count: 20
+# This cop supports safe auto-correction (--auto-correct).
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: single_quotes, double_quotes
+Style/StringLiteralsInInterpolation:
+  Exclude:
+    - 'lib/liquid/condition.rb'
+    - 'lib/liquid/strainer_template.rb'
+    - 'lib/liquid/tag/disableable.rb'
+    - 'performance/shopify/shop_filter.rb'
+    - 'performance/shopify/tag_filter.rb'
+
+# Offense count: 6
+# This cop supports safe auto-correction (--auto-correct).
+# Configuration parameters: EnforcedStyleForMultiline.
+# SupportedStylesForMultiline: comma, consistent_comma, no_comma
+Style/TrailingCommaInArrayLiteral:
+  Exclude:
+    - 'example/server/example_servlet.rb'
+    - 'lib/liquid/condition.rb'
+    - 'test/integration/context_test.rb'
+    - 'test/integration/standard_filter_test.rb'
+    - 'test/unit/parse_tree_visitor_test.rb'
+
+# Offense count: 1
+# This cop supports safe auto-correction (--auto-correct).
+# Configuration parameters: EnforcedStyleForMultiline.
+# SupportedStylesForMultiline: comma, consistent_comma, no_comma
+Style/TrailingCommaInHashLiteral:
+  Exclude:
+    - 'lib/liquid/expression.rb'
+
+# Offense count: 19
+# This cop supports safe auto-correction (--auto-correct).
+# Configuration parameters: EnforcedStyle, MinSize, WordRegex.
+# SupportedStyles: percent, brackets
+Style/WordArray:
+  Exclude:
+    - 'lib/liquid/tags/if.rb'
+    - 'liquid.gemspec'
+    - 'test/integration/assign_test.rb'
+    - 'test/integration/context_test.rb'
+    - 'test/integration/drop_test.rb'
+    - 'test/integration/standard_filter_test.rb'
+
+# Offense count: 117
+# This cop supports safe auto-correction (--auto-correct).
+# Configuration parameters: AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, AllowedPatterns, IgnoredPatterns.
+# URISchemes: http, https
+Layout/LineLength:
+  Max: 260

.ruby-version

@@ -0,0 +1 @@
+3.3.6

CONTRIBUTING.md

@@ -5,6 +5,7 @@
 * Bugfixes
 * Performance improvements
 * Features that are likely to be useful to the majority of Liquid users
+* Documentation updates that are concise and likely to be useful to the majority of Liquid users
 
 ## Things we won't merge
 
@@ -14,12 +15,14 @@
 * Features that can easily be implemented on top of Liquid (for example as a custom filter or custom filesystem)
 * Code that does not include tests
 * Code that breaks existing tests
+* Documentation changes that are verbose, incorrect or not important to most people (we want to keep it simple and easy to understand)
 
 ## Workflow
 
+* [Sign the CLA](https://cla.shopify.com/) if you haven't already
 * Fork the Liquid repository
 * Create a new branch in your fork
+  * For updating [Liquid documentation](https://shopify.github.io/liquid/), create it from `gh-pages` branch. (You can skip tests.)
 * If it makes sense, add tests for your code and/or run a performance benchmark
 * Make sure all tests pass (`bundle exec rake`)
 * Create a pull request
-

Gemfile

@@ -7,10 +7,13 @@ end
 
 gemspec
 
+gem "base64"
+
 group :benchmark, :test do
   gem 'benchmark-ips'
   gem 'memory_profiler'
   gem 'terminal-table'
+  gem "lru_redux"
 
   install_if -> { RUBY_PLATFORM !~ /mingw|mswin|java/ && RUBY_ENGINE != 'truffleruby' } do
     gem 'stackprof'
@@ -18,10 +21,7 @@ group :benchmark, :test do
 end
 
 group :test do
-  gem 'rubocop', '~> 1.4', require: false
+  gem 'rubocop', '~> 1.61.0'
+  gem 'rubocop-shopify', '~> 2.12.0', require: false
   gem 'rubocop-performance', require: false
-
-  platform :mri, :truffleruby do
-    gem 'liquid-c', github: 'Shopify/liquid-c', ref: 'master'
-  end
 end

History.md

@@ -1,5 +1,72 @@
 # Liquid Change Log
 
+## 5.6.0 (unreleased)
+
+### Fixes
+
+* Fix Tokenizer to handle null source value (#1873) [Bahar Pourazar]
+
+
+## 5.5.0 2024-03-21
+
+Please reference the GitHub release for more information.
+
+## 5.4.0 2022-07-29
+
+### Breaking Changes
+* Drop support for end-of-life Ruby versions (2.5 and 2.6) (#1578) [Andy Waite]
+
+### Features
+* Allow `#` to be used as an inline comment tag (#1498) [CP Clermont]
+
+### Fixes
+* `PartialCache` now shares snippet cache with subcontexts by default (#1553) [Chris AtLee]
+* Hash registers no longer leak into subcontexts as static registers (#1564) [Chris AtLee]
+* Fix `ParseTreeVisitor` for `with` variable expressions in `Render` tag (#1596) [CP Clermont]
+
+### Changed
+* Liquid::Context#registers now always returns a Liquid::Registers object, though supports the most used Hash functions for compatibility (#1553)
+
+## 5.3.0 2022-03-22
+
+### Fixes
+* StandardFilter: Fix missing @context on iterations (#1525) [Thierry Joyal]
+* Fix warning about block and default value in `static_registers.rb` (#1531) [Peter Zhu]
+
+### Deprecation
+* Condition#evaluate to require mandatory context argument in Liquid 6.0.0 (#1527) [Thierry Joyal]
+
+## 5.2.0 2022-03-01
+
+### Features
+* Add `remove_last`, and `replace_last` filters (#1422) [Anders Hagbard]
+* Eagerly cache global filters (#1524) [Jean Boussier]
+
+### Fixes
+* Fix some internal errors in filters from invalid input (#1476) [Dylan Thacker-Smith]
+* Allow dash in filter kwarg name for consistency with Liquid::C (#1518) [CP Clermont]
+
+## 5.1.0 / 2021-09-09
+
+### Features
+* Add `base64_encode`, `base64_decode`, `base64_url_safe_encode`, and `base64_url_safe_decode` filters (#1450) [Daniel Insley]
+* Introduce `to_liquid_value` in `Liquid::Drop` (#1441) [Michael Go]
+
+### Fixes
+* Fix support for using a String subclass for the liquid source (#1421) [Dylan Thacker-Smith]
+* Add `ParseTreeVisitor` to `RangeLookup` (#1470) [CP Clermont]
+* Translate `RangeError` to `Liquid::Error` for `truncatewords` with large int (#1431) [Dylan Thacker-Smith]
+
+## 5.0.1 / 2021-03-24
+
+### Fixes
+* Add ParseTreeVisitor to Echo tag (#1414) [CP Clermont]
+* Test with ruby 3.0 as the latest ruby version (#1398) [Dylan Thacker-Smith]
+* Handle carriage return in newlines_to_br (#1391) [Unending]
+
+### Performance Improvements
+* Use split limit in truncatewords (#1361) [Dylan Thacker-Smith]
+
 ## 5.0.0 / 2021-01-06
 
 ### Features

README.md

@@ -1,11 +1,11 @@
-[![Build Status](https://api.travis-ci.org/Shopify/liquid.svg?branch=master)](http://travis-ci.org/Shopify/liquid)
+[![Build status](https://github.com/Shopify/liquid/actions/workflows/liquid.yml/badge.svg)](https://github.com/Shopify/liquid/actions/workflows/liquid.yml)
 [![Inline docs](http://inch-ci.org/github/Shopify/liquid.svg?branch=master)](http://inch-ci.org/github/Shopify/liquid)
 
 # Liquid template engine
 
 * [Contributing guidelines](CONTRIBUTING.md)
 * [Version history](History.md)
-* [Liquid documentation from Shopify](http://docs.shopify.com/themes/liquid-basics)
+* [Liquid documentation from Shopify](https://shopify.dev/docs/api/liquid)
 * [Liquid Wiki at GitHub](https://github.com/Shopify/liquid/wiki)
 * [Website](http://liquidmarkup.org/)
 
@@ -52,24 +52,66 @@ For standard use you can just pass it the content of a file and call render with
 @template.render('name' => 'tobi')                # => "hi tobi"
 ```
 
+### Concept of Environments
+
+In Liquid, a "Environment" is a scoped environment that encapsulates custom tags, filters, and other configurations. This allows you to define and isolate different sets of functionality for different contexts, avoiding global overrides that can lead to conflicts and unexpected behavior.
+
+By using environments, you can:
+
+1. **Encapsulate Logic**: Keep the logic for different parts of your application separate.
+2. **Avoid Conflicts**: Prevent custom tags and filters from clashing with each other.
+3. **Improve Maintainability**: Make it easier to manage and understand the scope of customizations.
+4. **Enhance Security**: Limit the availability of certain tags and filters to specific contexts.
+
+We encourage the use of Environments over globally overriding things because it promotes better software design principles such as modularity, encapsulation, and separation of concerns.
+
+Here's an example of how you can define and use Environments in Liquid:
+
+```ruby
+user_environment = Liquid::Environment.build do |environment|
+  environment.register_tag("renderobj", RenderObjTag)
+end
+
+Liquid::Template.parse(<<~LIQUID, environment: user_environment)
+  {% renderobj src: "path/to/model.obj" %}
+LIQUID
+```
+
+In this example, `RenderObjTag` is a custom tag that is only available within the `user_environment`.
+
+Similarly, you can define another environment for a different context, such as email templates:
+
+```ruby
+email_environment = Liquid::Environment.build do |environment|
+  environment.register_tag("unsubscribe_footer", UnsubscribeFooter)
+end
+
+Liquid::Template.parse(<<~LIQUID, environment: email_environment)
+  {% unsubscribe_footer %}
+LIQUID
+```
+
+By using Environments, you ensure that custom tags and filters are only available in the contexts where they are needed, making your Liquid templates more robust and easier to manage. For smaller projects, a global environment is available via `Liquid::Environment.default`.
+
 ### Error Modes
 
 Setting the error mode of Liquid lets you specify how strictly you want your templates to be interpreted.
 Normally the parser is very lax and will accept almost anything without error. Unfortunately this can make
-it very hard to debug and can lead to unexpected behaviour. 
+it very hard to debug and can lead to unexpected behaviour.
 
 Liquid also comes with a stricter parser that can be used when editing templates to give better error messages
 when templates are invalid. You can enable this new parser like this:
 
 ```ruby
-Liquid::Template.error_mode = :strict # Raises a SyntaxError when invalid syntax is used
-Liquid::Template.error_mode = :warn # Adds errors to template.errors but continues as normal
-Liquid::Template.error_mode = :lax # The default mode, accepts almost anything.
+Liquid::Environment.default.error_mode = :strict
+Liquid::Environment.default.error_mode = :strict # Raises a SyntaxError when invalid syntax is used
+Liquid::Environment.default.error_mode = :warn # Adds strict errors to template.errors but continues as normal
+Liquid::Environment.default.error_mode = :lax # The default mode, accepts almost anything.
 ```
 
 If you want to set the error mode only on specific templates you can pass `:error_mode` as an option to `parse`:
 ```ruby
-Liquid::Template.parse(source, :error_mode => :strict)
+Liquid::Template.parse(source, error_mode: :strict)
 ```
 This is useful for doing things like enabling strict mode only in the theme editor.
 
@@ -111,4 +153,4 @@ template.render!({ 'x' => 1}, { strict_variables: true })
 
 To help track usages of a feature or code path in production, we have released opt-in usage tracking. To enable this, we provide an empty `Liquid:: Usage.increment` method which you can customize to your needs. The feature is well suited to https://github.com/Shopify/statsd-instrument. However, the choice of implementation is up to you.
 
-Once you have enabled usage tracking, we recommend reporting any events through Github Issues that your system may be logging. It is highly likely this event has been added to consider deprecating or improving code specific to this event, so please raise any concerns.
+Once you have enabled usage tracking, we recommend reporting any events through Github Issues that your system may be logging. It is highly likely this event has been added to consider deprecating or improving code specific to this event, so please raise any concerns.

Rakefile

@@ -43,8 +43,6 @@ task :test do
   Rake::Task['base_test'].invoke
 
   if RUBY_ENGINE == 'ruby' || RUBY_ENGINE == 'truffleruby'
-    ENV['LIQUID_C'] = '1'
-
     ENV['LIQUID_PARSER_MODE'] = 'lax'
     Rake::Task['integration_test'].reenable
     Rake::Task['integration_test'].invoke
@@ -73,7 +71,7 @@ end
 
 namespace :benchmark do
   desc "Run the liquid benchmark with lax parsing"
-  task :run do
+  task :lax do
     ruby "./performance/benchmark.rb lax"
   end
 
@@ -81,6 +79,33 @@ namespace :benchmark do
   task :strict do
     ruby "./performance/benchmark.rb strict"
   end
+
+  desc "Run the liquid benchmark with both lax and strict parsing"
+  task run: [:lax, :strict]
+
+  desc "Run unit benchmarks"
+  namespace :unit do
+    task :all do
+      Dir["./performance/unit/*_benchmark.rb"].each do |file|
+        puts "🧪 Running #{file}"
+        ruby file
+      end
+    end
+
+    task :lexer do
+      Dir["./performance/unit/lexer_benchmark.rb"].each do |file|
+        puts "🧪 Running #{file}"
+        ruby file
+      end
+    end
+
+    task :expression do
+      Dir["./performance/unit/expression_benchmark.rb"].each do |file|
+        puts "🧪 Running #{file}"
+        ruby file
+      end
+    end
+  end
 end
 
 namespace :profile do

example/server/example_servlet.rb

@@ -30,14 +30,18 @@ class Servlet < LiquidServlet
   private
 
   def products_list
-    [{ 'name' => 'Arbor Draft', 'price' => 39900, 'description' => 'the *arbor draft* is a excellent product' },
-     { 'name' => 'Arbor Element', 'price' => 40000, 'description' => 'the *arbor element* rocks for freestyling' },
-     { 'name' => 'Arbor Diamond', 'price' => 59900, 'description' => 'the *arbor diamond* is a made up product because im obsessed with arbor and have no creativity' }]
+    [
+      { 'name' => 'Arbor Draft', 'price' => 39900, 'description' => 'the *arbor draft* is a excellent product' },
+      { 'name' => 'Arbor Element', 'price' => 40000, 'description' => 'the *arbor element* rocks for freestyling' },
+      { 'name' => 'Arbor Diamond', 'price' => 59900, 'description' => 'the *arbor diamond* is a made up product because im obsessed with arbor and have no creativity' }
+    ]
   end
 
   def more_products_list
-    [{ 'name' => 'Arbor Catalyst', 'price' => 39900, 'description' => 'the *arbor catalyst* is an advanced drop-through for freestyle and flatground performance and versatility' },
-     { 'name' => 'Arbor Fish', 'price' => 40000, 'description' => 'the *arbor fish* is a compact pin that features an extended wheelbase and time-honored teardrop shape' }]
+    [
+      { 'name' => 'Arbor Catalyst', 'price' => 39900, 'description' => 'the *arbor catalyst* is an advanced drop-through for freestyle and flatground performance and versatility' },
+      { 'name' => 'Arbor Fish', 'price' => 40000, 'description' => 'the *arbor fish* is a compact pin that features an extended wheelbase and time-honored teardrop shape' }
+    ]
   end
 
   def description

lib/liquid.rb

@@ -21,6 +21,8 @@
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
+require "strscan"
+
 module Liquid
   FilterSeparator             = /\|/
   ArgumentSeparator           = ','
@@ -29,6 +31,7 @@ module Liquid
   WhitespaceControl           = '-'
   TagStart                    = /\{\%/
   TagEnd                      = /\%\}/
+  TagName                     = /#|\w+/
   VariableSignature           = /\(?[\w\-\.\[\]]\)?/
   VariableSegment             = /[\w\-]/
   VariableStart               = /\{\{/
@@ -36,20 +39,28 @@ module Liquid
   VariableIncompleteEnd       = /\}\}?/
   QuotedString                = /"[^"]*"|'[^']*'/
   QuotedFragment              = /#{QuotedString}|(?:[^\s,\|'"]|#{QuotedString})+/o
-  TagAttributes               = /(\w+)\s*\:\s*(#{QuotedFragment})/o
+  TagAttributes               = /(\w[\w-]*)\s*\:\s*(#{QuotedFragment})/o
   AnyStartingTag              = /#{TagStart}|#{VariableStart}/o
   PartialTemplateParser       = /#{TagStart}.*?#{TagEnd}|#{VariableStart}.*?#{VariableIncompleteEnd}/om
   TemplateParser              = /(#{PartialTemplateParser}|#{AnyStartingTag})/om
-  VariableParser              = /\[[^\]]+\]|#{VariableSegment}+\??/o
+  VariableParser              = /\[(?>[^\[\]]+|\g<0>)*\]|#{VariableSegment}+\??/o
 
   RAISE_EXCEPTION_LAMBDA = ->(_e) { raise }
-
-  singleton_class.send(:attr_accessor, :cache_classes)
-  self.cache_classes = true
+  HAS_STRING_SCANNER_SCAN_BYTE = StringScanner.instance_methods.include?(:scan_byte)
 end
 
 require "liquid/version"
+require "liquid/deprecations"
+require "liquid/const"
+require 'liquid/standardfilters'
+require 'liquid/file_system'
+require 'liquid/parser_switching'
+require 'liquid/tag'
+require 'liquid/block'
 require 'liquid/parse_tree_visitor'
+require 'liquid/interrupts'
+require 'liquid/tags'
+require "liquid/environment"
 require 'liquid/lexer'
 require 'liquid/parser'
 require 'liquid/i18n'
@@ -59,34 +70,22 @@ require 'liquid/forloop_drop'
 require 'liquid/extensions'
 require 'liquid/errors'
 require 'liquid/interrupts'
-require 'liquid/strainer_factory'
 require 'liquid/strainer_template'
-require 'liquid/expression'
 require 'liquid/context'
-require 'liquid/parser_switching'
 require 'liquid/tag'
-require 'liquid/tag/disabler'
-require 'liquid/tag/disableable'
-require 'liquid/block'
 require 'liquid/block_body'
 require 'liquid/document'
 require 'liquid/variable'
 require 'liquid/variable_lookup'
 require 'liquid/range_lookup'
-require 'liquid/file_system'
 require 'liquid/resource_limits'
+require 'liquid/expression'
 require 'liquid/template'
-require 'liquid/standardfilters'
 require 'liquid/condition'
 require 'liquid/utils'
 require 'liquid/tokenizer'
 require 'liquid/parse_context'
 require 'liquid/partial_cache'
 require 'liquid/usage'
-require 'liquid/register'
-require 'liquid/static_registers'
+require 'liquid/registers'
 require 'liquid/template_factory'
-
-# Load all the tags of the standard library
-#
-Dir["#{__dir__}/liquid/tags/*.rb"].each { |f| require f }

lib/liquid/block.rb

@@ -36,13 +36,17 @@ module Liquid
     # @api private
     def self.raise_unknown_tag(tag, block_name, block_delimiter, parse_context)
       if tag == 'else'
-        raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_else",
-          block_name: block_name)
+        raise SyntaxError, parse_context.locale.t(
+          "errors.syntax.unexpected_else",
+          block_name: block_name,
+        )
       elsif tag.start_with?('end')
-        raise SyntaxError, parse_context.locale.t("errors.syntax.invalid_delimiter",
+        raise SyntaxError, parse_context.locale.t(
+          "errors.syntax.invalid_delimiter",
           tag: tag,
           block_name: block_name,
-          block_delimiter: block_delimiter)
+          block_delimiter: block_delimiter,
+        )
       else
         raise SyntaxError, parse_context.locale.t("errors.syntax.unknown_tag", tag: tag)
       end

lib/liquid/block_body.rb

@@ -4,8 +4,9 @@ require 'English'
 
 module Liquid
   class BlockBody
-    LiquidTagToken      = /\A\s*(\w+)\s*(.*?)\z/o
-    FullToken           = /\A#{TagStart}#{WhitespaceControl}?(\s*)(\w+)(\s*)(.*?)#{WhitespaceControl}?#{TagEnd}\z/om
+    LiquidTagToken      = /\A\s*(#{TagName})\s*(.*?)\z/o
+    FullToken           = /\A#{TagStart}#{WhitespaceControl}?(\s*)(#{TagName})(\s*)(.*?)#{WhitespaceControl}?#{TagEnd}\z/om
+    FullTokenPossiblyInvalid = /\A(.*)#{TagStart}#{WhitespaceControl}?\s*(\w+)\s*(.*)?#{WhitespaceControl}?#{TagEnd}\z/om
     ContentOfVariable   = /\A#{VariableStart}#{WhitespaceControl}?(.*?)#{WhitespaceControl}?#{VariableEnd}\z/om
     WhitespaceOrNothing = /\A\s*\z/
     TAGSTART            = "{%"
@@ -37,7 +38,7 @@ module Liquid
 
     private def parse_for_liquid_tag(tokenizer, parse_context)
       while (token = tokenizer.shift)
-        unless token.empty? || token =~ WhitespaceOrNothing
+        unless token.empty? || token.match?(WhitespaceOrNothing)
           unless token =~ LiquidTagToken
             # line isn't empty but didn't match tag syntax, yield and let the
             # caller raise a syntax error
@@ -45,7 +46,13 @@ module Liquid
           end
           tag_name = Regexp.last_match(1)
           markup   = Regexp.last_match(2)
-          unless (tag = registered_tags[tag_name])
+
+          if tag_name == 'liquid'
+            parse_context.line_number -= 1
+            next parse_liquid_tag(markup, parse_context)
+          end
+
+          unless (tag = parse_context.environment.tag_for_name(tag_name))
             # end parsing if we reach an unknown tag and let the caller decide
             # determine how to proceed
             return yield tag_name, markup
@@ -109,14 +116,22 @@ module Liquid
       end
     end
 
-    private def parse_for_document(tokenizer, parse_context)
+    private def handle_invalid_tag_token(token, parse_context)
+      if token.end_with?('%}')
+        yield token, token
+      else
+        BlockBody.raise_missing_tag_terminator(token, parse_context)
+      end
+    end
+
+    private def parse_for_document(tokenizer, parse_context, &block)
       while (token = tokenizer.shift)
         next if token.empty?
         case
         when token.start_with?(TAGSTART)
           whitespace_handler(token, parse_context)
           unless token =~ FullToken
-            BlockBody.raise_missing_tag_terminator(token, parse_context)
+            return handle_invalid_tag_token(token, parse_context, &block)
           end
           tag_name = Regexp.last_match(2)
           markup   = Regexp.last_match(4)
@@ -132,7 +147,7 @@ module Liquid
             next
           end
 
-          unless (tag = registered_tags[tag_name])
+          unless (tag = parse_context.environment.tag_for_name(tag_name))
             # end parsing if we reach an unknown tag and let the caller decide
             # determine how to proceed
             return yield tag_name, markup
@@ -150,7 +165,7 @@ module Liquid
           end
           parse_context.trim_whitespace = false
           @nodelist << token
-          @blank &&= !!(token =~ WhitespaceOrNothing)
+          @blank &&= token.match?(WhitespaceOrNothing)
         end
         parse_context.line_number = tokenizer.line_number
       end
@@ -231,10 +246,17 @@ module Liquid
     end
 
     def create_variable(token, parse_context)
-      token.scan(ContentOfVariable) do |content|
-        markup = content.first
+      if token.end_with?("}}")
+        i = 2
+        i = 3 if token[i] == "-"
+        parse_end = token.length - 3
+        parse_end -= 1 if token[parse_end] == "-"
+        markup_end = parse_end - i + 1
+        markup = markup_end <= 0 ? "" : token.slice(i, markup_end)
+
         return Variable.new(markup, parse_context)
       end
+
       BlockBody.raise_missing_variable_terminator(token, parse_context)
     end
 
@@ -247,9 +269,5 @@ module Liquid
     def raise_missing_variable_terminator(token, parse_context)
       BlockBody.raise_missing_variable_terminator(token, parse_context)
     end
-
-    def registered_tags
-      Template.tags
-    end
   end
 end

lib/liquid/condition.rb

@@ -8,7 +8,7 @@ module Liquid
   #   c = Condition.new(1, '==', 1)
   #   c.evaluate #=> true
   #
-  class Condition #:nodoc:
+  class Condition # :nodoc:
     @@operators = {
       '==' => ->(cond, left, right) {  cond.send(:equal_variables, left, right) },
       '!=' => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
@@ -24,6 +24,9 @@ module Liquid
         else
           false
         end
+      rescue Encoding::CompatibilityError
+        # "✅".b.include?("✅") raises Encoding::CompatibilityError despite being materially equal
+        left.b.include?(right.b)
       end,
     }
 
@@ -61,7 +64,7 @@ module Liquid
       @child_condition = nil
     end
 
-    def evaluate(context = Context.new)
+    def evaluate(context = deprecated_default_context)
       condition = self
       result = nil
       loop do
@@ -69,9 +72,9 @@ module Liquid
 
         case condition.child_relation
         when :or
-          break if result
+          break if Liquid::Utils.to_liquid_value(result)
         when :and
-          break unless result
+          break unless Liquid::Utils.to_liquid_value(result)
         else
           break
         end
@@ -134,8 +137,8 @@ module Liquid
       # return this as the result.
       return context.evaluate(left) if op.nil?
 
-      left  = context.evaluate(left)
-      right = context.evaluate(right)
+      left  = Liquid::Utils.to_liquid_value(context.evaluate(left))
+      right = Liquid::Utils.to_liquid_value(context.evaluate(right))
 
       operation = self.class.operators[op] || raise(Liquid::ArgumentError, "Unknown operator #{op}")
 
@@ -150,11 +153,19 @@ module Liquid
       end
     end
 
+    def deprecated_default_context
+      warn("DEPRECATION WARNING: Condition#evaluate without a context argument is deprecated" \
+        " and will be removed from Liquid 6.0.0.")
+      Context.new
+    end
+
     class ParseTreeVisitor < Liquid::ParseTreeVisitor
       def children
         [
-          @node.left, @node.right,
-          @node.child_condition, @node.attachment
+          @node.left,
+          @node.right,
+          @node.child_condition,
+          @node.attachment
         ].compact
       end
     end

lib/liquid/const.rb

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Const
+    EMPTY_HASH = {}.freeze
+    EMPTY_ARRAY = [].freeze
+  end
+end

lib/liquid/context.rb

@@ -15,31 +15,40 @@ module Liquid
   #   context['bob']  #=> nil  class Context
   class Context
     attr_reader :scopes, :errors, :registers, :environments, :resource_limits, :static_registers, :static_environments
-    attr_accessor :exception_renderer, :template_name, :partial, :global_filter, :strict_variables, :strict_filters
+    attr_accessor :exception_renderer, :template_name, :partial, :global_filter, :strict_variables, :strict_filters, :environment
 
     # rubocop:disable Metrics/ParameterLists
-    def self.build(environments: {}, outer_scope: {}, registers: {}, rethrow_errors: false, resource_limits: nil, static_environments: {}, &block)
-      new(environments, outer_scope, registers, rethrow_errors, resource_limits, static_environments, &block)
+    def self.build(environment: Environment.default, environments: {}, outer_scope: {}, registers: {}, rethrow_errors: false, resource_limits: nil, static_environments: {}, &block)
+      new(environments, outer_scope, registers, rethrow_errors, resource_limits, static_environments, environment, &block)
     end
 
-    def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil, static_environments = {})
+    def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil, static_environments = {}, environment = Environment.default)
+      @environment = environment
       @environments = [environments]
       @environments.flatten!
 
-      @static_environments = [static_environments].flat_map(&:freeze).freeze
-      @scopes              = [(outer_scope || {})]
-      @registers           = registers
+      @static_environments = [static_environments].flatten(1).freeze
+      @scopes              = [outer_scope || {}]
+      @registers           = registers.is_a?(Registers) ? registers : Registers.new(registers)
       @errors              = []
       @partial             = false
       @strict_variables    = false
-      @resource_limits     = resource_limits || ResourceLimits.new(Template.default_resource_limits)
+      @resource_limits     = resource_limits || ResourceLimits.new(environment.default_resource_limits)
       @base_scope_depth    = 0
       @interrupts          = []
       @filters             = []
       @global_filter       = nil
       @disabled_tags       = {}
 
-      self.exception_renderer = Template.default_exception_renderer
+      # Instead of constructing new StringScanner objects for each Expression parse,
+      # we recycle the same one.
+      @string_scanner = StringScanner.new("")
+
+      @registers.static[:cached_partials] ||= {}
+      @registers.static[:file_system] ||= environment.file_system
+      @registers.static[:template_factory] ||= Liquid::TemplateFactory.new
+
+      self.exception_renderer = environment.exception_renderer
       if rethrow_errors
         self.exception_renderer = Liquid::RAISE_EXCEPTION_LAMBDA
       end
@@ -56,7 +65,7 @@ module Liquid
     end
 
     def strainer
-      @strainer ||= StrainerFactory.create(self, @filters)
+      @strainer ||= @environment.create_strainer(self, @filters)
     end
 
     # Adds filters to this context.
@@ -124,7 +133,7 @@ module Liquid
     #      context['var'] = 'hi'
     #   end
     #
-    #   context['var]  #=> nil
+    #   context['var']  #=> nil
     def stack(new_scope = {})
       push(new_scope)
       yield
@@ -138,9 +147,10 @@ module Liquid
       check_overflow
 
       self.class.build(
+        environment: @environment,
         resource_limits: resource_limits,
         static_environments: static_environments,
-        registers: StaticRegisters.new(registers)
+        registers: Registers.new(registers),
       ).tap do |subcontext|
         subcontext.base_scope_depth   = base_scope_depth + 1
         subcontext.exception_renderer = exception_renderer
@@ -170,7 +180,7 @@ module Liquid
     # Example:
     #   products == empty #=> products.empty?
     def [](expression)
-      evaluate(Expression.parse(expression))
+      evaluate(Expression.parse(expression, @string_scanner))
     end
 
     def key?(key)
@@ -193,10 +203,14 @@ module Liquid
         try_variable_find_in_environments(key, raise_on_not_found: raise_on_not_found)
       end
 
-      variable         = variable.to_liquid
+      # update variable's context before invoking #to_liquid
       variable.context = self if variable.respond_to?(:context=)
 
-      variable
+      liquid_variable = variable.to_liquid
+
+      liquid_variable.context = self if variable != liquid_variable && liquid_variable.respond_to?(:context=)
+
+      liquid_variable
     end
 
     def lookup_and_evaluate(obj, key, raise_on_not_found: true)

lib/liquid/deprecations.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+require "set"
+
+module Liquid
+  class Deprecations
+    class << self
+      attr_accessor :warned
+
+      Deprecations.warned = Set.new
+
+      def warn(name, alternative)
+        return if warned.include?(name)
+
+        warned << name
+
+        caller_location = caller_locations(2, 1).first
+        Warning.warn("[DEPRECATION] #{name} is deprecated. Use #{alternative} instead. Called from #{caller_location}\n")
+      end
+    end
+  end
+end

lib/liquid/drop.rb

@@ -25,6 +25,10 @@ module Liquid
   class Drop
     attr_writer :context
 
+    def initialize
+      @context = nil
+    end
+
     # Catch all for the method
     def liquid_method_missing(method)
       return nil unless @context&.strict_variables

lib/liquid/environment.rb

@@ -0,0 +1,159 @@
+# frozen_string_literal: true
+
+module Liquid
+  # The Environment is the container for all configuration options of Liquid, such as
+  # the registered tags, filters, and the default error mode.
+  class Environment
+    # The default error mode for all templates. This can be overridden on a
+    # per-template basis.
+    attr_accessor :error_mode
+
+    # The tags that are available to use in the template.
+    attr_accessor :tags
+
+    # The strainer template which is used to store filters that are available to
+    # use in templates.
+    attr_accessor :strainer_template
+
+    # The exception renderer that is used to render exceptions that are raised
+    # when rendering a template
+    attr_accessor :exception_renderer
+
+    # The default file system that is used to load templates from.
+    attr_accessor :file_system
+
+    # The default resource limits that are used to limit the resources that a
+    # template can consume.
+    attr_accessor :default_resource_limits
+
+    class << self
+      # Creates a new environment instance.
+      #
+      # @param tags [Hash] The tags that are available to use in
+      #  the template.
+      # @param file_system The default file system that is used
+      #  to load templates from.
+      # @param error_mode [Symbol] The default error mode for all templates
+      #  (either :strict, :warn, or :lax).
+      # @param exception_renderer [Proc] The exception renderer that is used to
+      #   render exceptions.
+      # @yieldparam environment [Environment] The environment instance that is being built.
+      # @return [Environment] The new environment instance.
+      def build(tags: nil, file_system: nil, error_mode: nil, exception_renderer: nil)
+        ret = new
+        ret.tags = tags if tags
+        ret.file_system = file_system if file_system
+        ret.error_mode = error_mode if error_mode
+        ret.exception_renderer = exception_renderer if exception_renderer
+        yield ret if block_given?
+        ret.freeze
+      end
+
+      # Returns the default environment instance.
+      #
+      # @return [Environment] The default environment instance.
+      def default
+        @default ||= new
+      end
+
+      # Sets the default environment instance for the duration of the block
+      #
+      # @param environment [Environment] The environment instance to use as the default for the
+      #   duration of the block.
+      # @yield
+      # @return [Object] The return value of the block.
+      def dangerously_override(environment)
+        original_default = @default
+        @default = environment
+        yield
+      ensure
+        @default = original_default
+      end
+    end
+
+    # Initializes a new environment instance.
+    # @api private
+    def initialize
+      @tags = Tags::STANDARD_TAGS.dup
+      @error_mode = :lax
+      @strainer_template = Class.new(StrainerTemplate).tap do |klass|
+        klass.add_filter(StandardFilters)
+      end
+      @exception_renderer = ->(exception) { exception }
+      @file_system = BlankFileSystem.new
+      @default_resource_limits = Const::EMPTY_HASH
+      @strainer_template_class_cache = {}
+    end
+
+    # Registers a new tag with the environment.
+    #
+    # @param name [String] The name of the tag.
+    # @param klass [Liquid::Tag] The class that implements the tag.
+    # @return [void]
+    def register_tag(name, klass)
+      @tags[name] = klass
+    end
+
+    # Registers a new filter with the environment.
+    #
+    # @param filter [Module] The module that contains the filter methods.
+    # @return [void]
+    def register_filter(filter)
+      @strainer_template_class_cache.clear
+      @strainer_template.add_filter(filter)
+    end
+
+    # Registers multiple filters with this environment.
+    #
+    # @param filters [Array<Module>] The modules that contain the filter methods.
+    # @return [self]
+    def register_filters(filters)
+      @strainer_template_class_cache.clear
+      filters.each { |f| @strainer_template.add_filter(f) }
+      self
+    end
+
+    # Creates a new strainer instance with the given filters, caching the result
+    # for faster lookup.
+    #
+    # @param context [Liquid::Context] The context that the strainer will be
+    #   used in.
+    # @param filters [Array<Module>] The filters that the strainer will have
+    #   access to.
+    # @return [Liquid::Strainer] The new strainer instance.
+    def create_strainer(context, filters = Const::EMPTY_ARRAY)
+      return @strainer_template.new(context) if filters.empty?
+
+      strainer_template = @strainer_template_class_cache[filters] ||= begin
+        klass = Class.new(@strainer_template)
+        filters.each { |f| klass.add_filter(f) }
+        klass
+      end
+
+      strainer_template.new(context)
+    end
+
+    # Returns the names of all the filter methods that are available to use in
+    # the strainer template.
+    #
+    # @return [Array<String>] The names of all the filter methods.
+    def filter_method_names
+      @strainer_template.filter_method_names
+    end
+
+    # Returns the tag class for the given tag name.
+    #
+    # @param name [String] The name of the tag.
+    # @return [Liquid::Tag] The tag class.
+    def tag_for_name(name)
+      @tags[name]
+    end
+
+    def freeze
+      @tags.freeze
+      # TODO: freeze the tags, currently this is not possible because of liquid-c
+      # @strainer_template.freeze
+      super
+    end
+  end
+end

lib/liquid/errors.rb

@@ -40,19 +40,20 @@ module Liquid
     end
   end
 
-  ArgumentError       = Class.new(Error)
-  ContextError        = Class.new(Error)
-  FileSystemError     = Class.new(Error)
-  StandardError       = Class.new(Error)
-  SyntaxError         = Class.new(Error)
-  StackLevelError     = Class.new(Error)
-  MemoryError         = Class.new(Error)
-  ZeroDivisionError   = Class.new(Error)
-  FloatDomainError    = Class.new(Error)
-  UndefinedVariable   = Class.new(Error)
-  UndefinedDropMethod = Class.new(Error)
-  UndefinedFilter     = Class.new(Error)
-  MethodOverrideError = Class.new(Error)
-  DisabledError       = Class.new(Error)
-  InternalError       = Class.new(Error)
+  ArgumentError         = Class.new(Error)
+  ContextError          = Class.new(Error)
+  FileSystemError       = Class.new(Error)
+  StandardError         = Class.new(Error)
+  SyntaxError           = Class.new(Error)
+  StackLevelError       = Class.new(Error)
+  MemoryError           = Class.new(Error)
+  ZeroDivisionError     = Class.new(Error)
+  FloatDomainError      = Class.new(Error)
+  UndefinedVariable     = Class.new(Error)
+  UndefinedDropMethod   = Class.new(Error)
+  UndefinedFilter       = Class.new(Error)
+  MethodOverrideError   = Class.new(Error)
+  DisabledError         = Class.new(Error)
+  InternalError         = Class.new(Error)
+  TemplateEncodingError = Class.new(Error)
 end

lib/liquid/expression.rb

@@ -3,40 +3,120 @@
 module Liquid
   class Expression
     LITERALS = {
-      nil => nil, 'nil' => nil, 'null' => nil, '' => nil,
+      nil => nil,
+      'nil' => nil,
+      'null' => nil,
+      '' => nil,
       'true' => true,
       'false' => false,
       'blank' => '',
-      'empty' => ''
+      'empty' => '',
+      # in lax mode, minus sign can be a VariableLookup
+      # For simplicity and performace, we treat it like a literal
+      '-' => VariableLookup.parse("-", nil).freeze,
     }.freeze
 
-    SINGLE_QUOTED_STRING = /\A\s*'(.*)'\s*\z/m
-    DOUBLE_QUOTED_STRING = /\A\s*"(.*)"\s*\z/m
-    INTEGERS_REGEX       = /\A\s*(-?\d+)\s*\z/
-    FLOATS_REGEX         = /\A\s*(-?\d[\d\.]+)\s*\z/
+    DOT = ".".ord
+    ZERO = "0".ord
+    NINE = "9".ord
+    DASH = "-".ord
 
     # Use an atomic group (?>...) to avoid pathological backtracing from
     # malicious input as described in https://github.com/Shopify/liquid/issues/1357
-    RANGES_REGEX         = /\A\s*\(\s*(?>(\S+)\s*\.\.)\s*(\S+)\s*\)\s*\z/
+    RANGES_REGEX = /\A\(\s*(?>(\S+)\s*\.\.)\s*(\S+)\s*\)\z/
+    INTEGER_REGEX = /\A(-?\d+)\z/
+    FLOAT_REGEX = /\A(-?\d+)\.\d+\z/
 
-    def self.parse(markup)
-      case markup
-      when nil
-        nil
-      when SINGLE_QUOTED_STRING, DOUBLE_QUOTED_STRING
-        Regexp.last_match(1)
-      when INTEGERS_REGEX
-        Regexp.last_match(1).to_i
-      when RANGES_REGEX
-        RangeLookup.parse(Regexp.last_match(1), Regexp.last_match(2))
-      when FLOATS_REGEX
-        Regexp.last_match(1).to_f
-      else
-        markup = markup.strip
-        if LITERALS.key?(markup)
-          LITERALS[markup]
+    class << self
+      def parse(markup, ss = StringScanner.new(""), cache = nil)
+        return unless markup
+
+        markup = markup.strip # markup can be a frozen string
+
+        if (markup.start_with?('"') && markup.end_with?('"')) ||
+          (markup.start_with?("'") && markup.end_with?("'"))
+          return markup[1..-2]
+        elsif LITERALS.key?(markup)
+          return LITERALS[markup]
+        end
+
+        # Cache only exists during parsing
+        if cache
+          return cache[markup] if cache.key?(markup)
+
+          cache[markup] = inner_parse(markup, ss, cache).freeze
         else
-          VariableLookup.parse(markup)
+          inner_parse(markup, ss, nil).freeze
+        end
+      end
+
+      def inner_parse(markup, ss, cache)
+        if (markup.start_with?("(") && markup.end_with?(")")) && markup =~ RANGES_REGEX
+          return RangeLookup.parse(
+            Regexp.last_match(1),
+            Regexp.last_match(2),
+            ss,
+            cache,
+          )
+        end
+
+        if (num = parse_number(markup, ss))
+          num
+        else
+          VariableLookup.parse(markup, ss, cache)
+        end
+      end
+
+      def parse_number(markup, ss)
+        # check if the markup is simple integer or float
+        case markup
+        when INTEGER_REGEX
+          return Integer(markup, 10)
+        when FLOAT_REGEX
+          return markup.to_f
+        end
+
+        ss.string = markup
+        # the first byte must be a digit or  a dash
+        byte = ss.scan_byte
+
+        return false if byte != DASH && (byte < ZERO || byte > NINE)
+
+        if byte == DASH
+          peek_byte = ss.peek_byte
+
+          # if it starts with a dash, the next byte must be a digit
+          return false if peek_byte.nil? || !(peek_byte >= ZERO && peek_byte <= NINE)
+        end
+
+        # The markup could be a float with multiple dots
+        first_dot_pos = nil
+        num_end_pos = nil
+
+        while (byte = ss.scan_byte)
+          return false if byte != DOT && (byte < ZERO || byte > NINE)
+
+          # we found our number and now we are just scanning the rest of the string
+          next if num_end_pos
+
+          if byte == DOT
+            if first_dot_pos.nil?
+              first_dot_pos = ss.pos
+            else
+              # we found another dot, so we know that the number ends here
+              num_end_pos = ss.pos - 1
+            end
+          end
+        end
+
+        num_end_pos = markup.length if ss.eos?
+
+        if num_end_pos
+          # number ends with a number "123.123"
+          markup.byteslice(0, num_end_pos).to_f
+        else
+          # number ends with a dot "123."
+          markup.byteslice(0, first_dot_pos).to_f
         end
       end
     end

lib/liquid/forloop_drop.rb

@@ -1,6 +1,11 @@
 # frozen_string_literal: true
 
 module Liquid
+  # @liquid_public_docs
+  # @liquid_type object
+  # @liquid_name forloop
+  # @liquid_summary
+  #   Information about a parent [`for` loop](/docs/api/liquid/tags/for).
   class ForloopDrop < Drop
     def initialize(name, length, parentloop)
       @name       = name
@@ -9,33 +14,68 @@ module Liquid
       @index      = 0
     end
 
-    attr_reader :length, :parentloop
+    # @liquid_public_docs
+    # @liquid_name length
+    # @liquid_summary
+    #   The total number of iterations in the loop.
+    # @liquid_return [number]
+    attr_reader :length
 
-    def name
-      Usage.increment('forloop_drop_name')
-      @name
-    end
+    # @liquid_public_docs
+    # @liquid_name parentloop
+    # @liquid_summary
+    #   The parent `forloop` object.
+    # @liquid_description
+    #   If the current `for` loop isn't nested inside another `for` loop, then `nil` is returned.
+    # @liquid_return [forloop]
+    attr_reader :parentloop
 
+    attr_reader :name
+
+    # @liquid_public_docs
+    # @liquid_summary
+    #   The 1-based index of the current iteration.
+    # @liquid_return [number]
     def index
       @index + 1
     end
 
+    # @liquid_public_docs
+    # @liquid_summary
+    #   The 0-based index of the current iteration.
+    # @liquid_return [number]
     def index0
       @index
     end
 
+    # @liquid_public_docs
+    # @liquid_summary
+    #   The 1-based index of the current iteration, in reverse order.
+    # @liquid_return [number]
     def rindex
       @length - @index
     end
 
+    # @liquid_public_docs
+    # @liquid_summary
+    #   The 0-based index of the current iteration, in reverse order.
+    # @liquid_return [number]
     def rindex0
       @length - @index - 1
     end
 
+    # @liquid_public_docs
+    # @liquid_summary
+    #   Returns `true` if the current iteration is the first. Returns `false` if not.
+    # @liquid_return [boolean]
     def first
       @index == 0
     end
 
+    # @liquid_public_docs
+    # @liquid_summary
+    #   Returns `true` if the current iteration is the last. Returns `false` if not.
+    # @liquid_return [boolean]
     def last
       @index == @length - 1
     end

lib/liquid/lexer.rb

@@ -1,62 +1,173 @@
 # frozen_string_literal: true
 
-require "strscan"
 module Liquid
   class Lexer
-    SPECIALS = {
-      '|' => :pipe,
-      '.' => :dot,
-      ':' => :colon,
-      ',' => :comma,
-      '[' => :open_square,
-      ']' => :close_square,
-      '(' => :open_round,
-      ')' => :close_round,
-      '?' => :question,
-      '-' => :dash,
-    }.freeze
-    IDENTIFIER            = /[a-zA-Z_][\w-]*\??/
-    SINGLE_STRING_LITERAL = /'[^\']*'/
+    CLOSE_ROUND = [:close_round, ")"].freeze
+    CLOSE_SQUARE = [:close_square, "]"].freeze
+    COLON = [:colon, ":"].freeze
+    COMMA = [:comma, ","].freeze
+    COMPARISION_NOT_EQUAL = [:comparison, "!="].freeze
+    COMPARISON_CONTAINS = [:comparison, "contains"].freeze
+    COMPARISON_EQUAL = [:comparison, "=="].freeze
+    COMPARISON_GREATER_THAN = [:comparison, ">"].freeze
+    COMPARISON_GREATER_THAN_OR_EQUAL = [:comparison, ">="].freeze
+    COMPARISON_LESS_THAN = [:comparison, "<"].freeze
+    COMPARISON_LESS_THAN_OR_EQUAL = [:comparison, "<="].freeze
+    COMPARISON_NOT_EQUAL_ALT = [:comparison, "<>"].freeze
+    DASH = [:dash, "-"].freeze
+    DOT = [:dot, "."].freeze
+    DOTDOT = [:dotdot, ".."].freeze
+    DOT_ORD = ".".ord
     DOUBLE_STRING_LITERAL = /"[^\"]*"/
+    EOS = [:end_of_string].freeze
+    IDENTIFIER            = /[a-zA-Z_][\w-]*\??/
     NUMBER_LITERAL        = /-?\d+(\.\d+)?/
-    DOTDOT                = /\.\./
-    COMPARISON_OPERATOR   = /==|!=|<>|<=?|>=?|contains(?=\s)/
+    OPEN_ROUND = [:open_round, "("].freeze
+    OPEN_SQUARE = [:open_square, "["].freeze
+    PIPE = [:pipe, "|"].freeze
+    QUESTION = [:question, "?"].freeze
+    RUBY_WHITESPACE = [" ", "\t", "\r", "\n", "\f"].freeze
+    SINGLE_STRING_LITERAL = /'[^\']*'/
     WHITESPACE_OR_NOTHING = /\s*/
 
-    def initialize(input)
-      @ss = StringScanner.new(input)
+    SINGLE_COMPARISON_TOKENS = [].tap do |table|
+      table["<".ord] = COMPARISON_LESS_THAN
+      table[">".ord] = COMPARISON_GREATER_THAN
+      table.freeze
     end
 
-    def tokenize
-      @output = []
+    TWO_CHARS_COMPARISON_JUMP_TABLE = [].tap do |table|
+      table["=".ord] = [].tap do |sub_table|
+        sub_table["=".ord] = COMPARISON_EQUAL
+        sub_table.freeze
+      end
+      table["!".ord] = [].tap do |sub_table|
+        sub_table["=".ord] = COMPARISION_NOT_EQUAL
+        sub_table.freeze
+      end
+      table.freeze
+    end
 
-      until @ss.eos?
-        @ss.skip(WHITESPACE_OR_NOTHING)
-        break if @ss.eos?
-        tok      = if (t = @ss.scan(COMPARISON_OPERATOR))
-          [:comparison, t]
-        elsif (t = @ss.scan(SINGLE_STRING_LITERAL))
-          [:string, t]
-        elsif (t = @ss.scan(DOUBLE_STRING_LITERAL))
-          [:string, t]
-        elsif (t = @ss.scan(NUMBER_LITERAL))
-          [:number, t]
-        elsif (t = @ss.scan(IDENTIFIER))
-          [:id, t]
-        elsif (t = @ss.scan(DOTDOT))
-          [:dotdot, t]
-        else
-          c     = @ss.getch
-          if (s = SPECIALS[c])
-            [s, c]
+    COMPARISON_JUMP_TABLE = [].tap do |table|
+      table["<".ord] = [].tap do |sub_table|
+        sub_table["=".ord] = COMPARISON_LESS_THAN_OR_EQUAL
+        sub_table[">".ord] = COMPARISON_NOT_EQUAL_ALT
+        sub_table.freeze
+      end
+      table[">".ord] = [].tap do |sub_table|
+        sub_table["=".ord] = COMPARISON_GREATER_THAN_OR_EQUAL
+        sub_table.freeze
+      end
+      table.freeze
+    end
+
+    NEXT_MATCHER_JUMP_TABLE = [].tap do |table|
+      "a".upto("z") do |c|
+        table[c.ord] = [:id, IDENTIFIER].freeze
+        table[c.upcase.ord] = [:id, IDENTIFIER].freeze
+      end
+      table["_".ord] = [:id, IDENTIFIER].freeze
+
+      "0".upto("9") do |c|
+        table[c.ord] = [:number, NUMBER_LITERAL].freeze
+      end
+      table["-".ord] = [:number, NUMBER_LITERAL].freeze
+
+      table["'".ord] = [:string, SINGLE_STRING_LITERAL].freeze
+      table["\"".ord] = [:string, DOUBLE_STRING_LITERAL].freeze
+      table.freeze
+    end
+
+    SPECIAL_TABLE = [].tap do |table|
+      table["|".ord] = PIPE
+      table[".".ord] = DOT
+      table[":".ord] = COLON
+      table[",".ord] = COMMA
+      table["[".ord] = OPEN_SQUARE
+      table["]".ord] = CLOSE_SQUARE
+      table["(".ord] = OPEN_ROUND
+      table[")".ord] = CLOSE_ROUND
+      table["?".ord] = QUESTION
+      table["-".ord] = DASH
+    end
+
+    NUMBER_TABLE = [].tap do |table|
+      "0".upto("9") do |c|
+        table[c.ord] = true
+      end
+      table.freeze
+    end
+
+    # rubocop:disable Metrics/BlockNesting
+    class << self
+      def tokenize(ss)
+        output = []
+
+        until ss.eos?
+          ss.skip(WHITESPACE_OR_NOTHING)
+
+          break if ss.eos?
+
+          start_pos = ss.pos
+          peeked = ss.peek_byte
+
+          if (special = SPECIAL_TABLE[peeked])
+            ss.scan_byte
+            # Special case for ".."
+            if special == DOT && ss.peek_byte == DOT_ORD
+              ss.scan_byte
+              output << DOTDOT
+            elsif special == DASH
+              # Special case for negative numbers
+              if (peeked_byte = ss.peek_byte) && NUMBER_TABLE[peeked_byte]
+                ss.pos -= 1
+                output << [:number, ss.scan(NUMBER_LITERAL)]
+              else
+                output << special
+              end
+            else
+              output << special
+            end
+          elsif (sub_table = TWO_CHARS_COMPARISON_JUMP_TABLE[peeked])
+            ss.scan_byte
+            if (peeked_byte = ss.peek_byte) && (found = sub_table[peeked_byte])
+              output << found
+              ss.scan_byte
+            else
+              raise_syntax_error(start_pos, ss)
+            end
+          elsif (sub_table = COMPARISON_JUMP_TABLE[peeked])
+            ss.scan_byte
+            if (peeked_byte = ss.peek_byte) && (found = sub_table[peeked_byte])
+              output << found
+              ss.scan_byte
+            else
+              output << SINGLE_COMPARISON_TOKENS[peeked]
+            end
           else
-            raise SyntaxError, "Unexpected character #{c}"
+            type, pattern = NEXT_MATCHER_JUMP_TABLE[peeked]
+
+            if type && (t = ss.scan(pattern))
+              # Special case for "contains"
+              output << if type == :id && t == "contains" && output.last&.first != :dot
+                COMPARISON_CONTAINS
+              else
+                [type, t]
+              end
+            else
+              raise_syntax_error(start_pos, ss)
+            end
           end
         end
-        @output << tok
+        # rubocop:enable Metrics/BlockNesting
+        output << EOS
       end
 
-      @output << [:end_of_string]
+      def raise_syntax_error(start_pos, ss)
+        ss.pos = start_pos
+        # the character could be a UTF-8 character, use getch to get all the bytes
+        raise SyntaxError, "Unexpected character #{ss.getch}"
+      end
     end
   end
 end

lib/liquid/locales/en.yml

@@ -13,15 +13,17 @@
       for_invalid_attribute: "Invalid attribute in for loop. Valid attributes are limit and offset"
       if: "Syntax Error in tag 'if' - Valid syntax: if [expression]"
       include: "Error in tag 'include' - Valid syntax: include '[template]' (with|for) [object|collection]"
-      unknown_tag: "Unknown tag '%{tag}'"
+      inline_comment_invalid: "Syntax error in tag '#' - Each line of comments must be prefixed by the '#' character"
       invalid_delimiter: "'%{tag}' is not a valid delimiter for %{block_name} tags. use %{block_delimiter}"
+      invalid_template_encoding: "Invalid template encoding"
+      render: "Syntax error in tag 'render' - Template name must be a quoted string"
+      table_row: "Syntax Error in 'table_row loop' - Valid syntax: table_row [item] in [collection] cols=3"
+      tag_never_closed: "'%{block_name}' tag was never closed"
+      tag_termination: "Tag '%{token}' was not properly terminated with regexp: %{tag_end}"
       unexpected_else: "%{block_name} tag does not expect 'else' tag"
       unexpected_outer_tag: "Unexpected outer '%{tag}' tag"
-      tag_termination: "Tag '%{token}' was not properly terminated with regexp: %{tag_end}"
+      unknown_tag: "Unknown tag '%{tag}'"
       variable_termination: "Variable '%{token}' was not properly terminated with regexp: %{tag_end}"
-      tag_never_closed: "'%{block_name}' tag was never closed"
-      table_row: "Syntax Error in 'table_row loop' - Valid syntax: table_row [item] in [collection] cols=3"
-      render: "Syntax error in tag 'render' - Template name must be a quoted string"
     argument:
       include: "Argument error in tag 'include' - Illegal template name"
     disabled:

lib/liquid/parse_context.rb

@@ -3,14 +3,27 @@
 module Liquid
   class ParseContext
     attr_accessor :locale, :line_number, :trim_whitespace, :depth
-    attr_reader :partial, :warnings, :error_mode
+    attr_reader :partial, :warnings, :error_mode, :environment
 
-    def initialize(options = {})
+    def initialize(options = Const::EMPTY_HASH)
+      @environment = options.fetch(:environment, Environment.default)
       @template_options = options ? options.dup : {}
 
       @locale   = @template_options[:locale] ||= I18n.new
       @warnings = []
 
+      # constructing new StringScanner in Lexer, Tokenizer, etc is expensive
+      # This StringScanner will be shared by all of them
+      @string_scanner = StringScanner.new("")
+
+      @expression_cache = if options[:expression_cache].nil?
+        {}
+      elsif options[:expression_cache].respond_to?(:[]) && options[:expression_cache].respond_to?(:[]=)
+        options[:expression_cache]
+      elsif options[:expression_cache]
+        {}
+      end
+
       self.depth   = 0
       self.partial = false
     end
@@ -23,19 +36,29 @@ module Liquid
       Liquid::BlockBody.new
     end
 
-    def new_tokenizer(markup, start_line_number: nil, for_liquid_tag: false)
-      Tokenizer.new(markup, line_number: start_line_number, for_liquid_tag: for_liquid_tag)
+    def new_parser(input)
+      @string_scanner.string = input
+      Parser.new(@string_scanner)
+    end
+
+    def new_tokenizer(source, start_line_number: nil, for_liquid_tag: false)
+      Tokenizer.new(
+        source: source,
+        string_scanner: @string_scanner,
+        line_number: start_line_number,
+        for_liquid_tag: for_liquid_tag,
+      )
     end
 
     def parse_expression(markup)
-      Expression.parse(markup)
+      Expression.parse(markup, @string_scanner, @expression_cache)
     end
 
     def partial=(value)
       @partial = value
       @options = value ? partial_options : @template_options
 
-      @error_mode = @options[:error_mode] || Template.error_mode
+      @error_mode = @options[:error_mode] || @environment.error_mode
     end
 
     def partial_options

lib/liquid/parse_tree_visitor.rb

@@ -36,7 +36,7 @@ module Liquid
     protected
 
     def children
-      @node.respond_to?(:nodelist) ? Array(@node.nodelist) : []
+      @node.respond_to?(:nodelist) ? Array(@node.nodelist) : Const::EMPTY_ARRAY
     end
   end
 end

lib/liquid/parser.rb

@@ -3,8 +3,8 @@
 module Liquid
   class Parser
     def initialize(input)
-      l       = Lexer.new(input)
-      @tokens = l.tokenize
+      ss = input.is_a?(StringScanner) ? input : StringScanner.new(input)
+      @tokens = Lexer.tokenize(ss)
       @p      = 0 # pointer to current location
     end
 
@@ -53,7 +53,7 @@ module Liquid
         str = consume
         str << variable_lookups
       when :open_square
-        str = consume
+        str = consume.dup
         str << expression
         str << consume(:close_square)
         str << variable_lookups

lib/liquid/partial_cache.rb

@@ -3,20 +3,29 @@
 module Liquid
   class PartialCache
     def self.load(template_name, context:, parse_context:)
-      cached_partials = (context.registers[:cached_partials] ||= {})
-      cached = cached_partials[template_name]
+      cached_partials = context.registers[:cached_partials]
+      cache_key = "#{template_name}:#{parse_context.error_mode}"
+      cached = cached_partials[cache_key]
       return cached if cached
 
-      file_system = (context.registers[:file_system] ||= Liquid::Template.file_system)
+      file_system = context.registers[:file_system]
       source      = file_system.read_template_file(template_name)
 
       parse_context.partial = true
 
-      template_factory = (context.registers[:template_factory] ||= Liquid::TemplateFactory.new)
+      template_factory = context.registers[:template_factory]
       template = template_factory.for(template_name)
 
-      partial = template.parse(source, parse_context)
-      cached_partials[template_name] = partial
+      begin
+        partial = template.parse(source, parse_context)
+      rescue Liquid::Error => e
+        e.template_name = template&.name || template_name
+        raise e
+      end
+
+      partial.name ||= template_name
+
+      cached_partials[cache_key] = partial
     ensure
       parse_context.partial = false
     end

lib/liquid/range_lookup.rb

@@ -2,16 +2,28 @@
 
 module Liquid
   class RangeLookup
-    def self.parse(start_markup, end_markup)
-      start_obj = Expression.parse(start_markup)
-      end_obj   = Expression.parse(end_markup)
+    def self.parse(start_markup, end_markup, string_scanner, cache = nil)
+      start_obj = Expression.parse(start_markup, string_scanner, cache)
+      end_obj   = Expression.parse(end_markup, string_scanner, cache)
       if start_obj.respond_to?(:evaluate) || end_obj.respond_to?(:evaluate)
         new(start_obj, end_obj)
       else
-        start_obj.to_i..end_obj.to_i
+        begin
+          start_obj.to_i..end_obj.to_i
+        rescue NoMethodError
+          invalid_expr = start_markup unless start_obj.respond_to?(:to_i)
+          invalid_expr ||= end_markup unless end_obj.respond_to?(:to_i)
+          if invalid_expr
+            raise Liquid::SyntaxError, "Invalid expression type '#{invalid_expr}' in range expression"
+          end
+
+          raise
+        end
       end
     end
 
+    attr_reader :start_obj, :end_obj
+
     def initialize(start_obj, end_obj)
       @start_obj = start_obj
       @end_obj   = end_obj
@@ -35,5 +47,11 @@ module Liquid
         Utils.to_integer(input)
       end
     end
+
+    class ParseTreeVisitor < Liquid::ParseTreeVisitor
+      def children
+        [@node.start_obj, @node.end_obj]
+      end
+    end
   end
 end

lib/liquid/register.rb

@@ -1,6 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  class Register
-  end
-end

lib/liquid/registers.rb

@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+module Liquid
+  class Registers
+    attr_reader :static
+
+    def initialize(registers = {})
+      @static = registers.is_a?(Registers) ? registers.static : registers
+      @changes = {}
+    end
+
+    def []=(key, value)
+      @changes[key] = value
+    end
+
+    def [](key)
+      if @changes.key?(key)
+        @changes[key]
+      else
+        @static[key]
+      end
+    end
+
+    def delete(key)
+      @changes.delete(key)
+    end
+
+    UNDEFINED = Object.new
+
+    def fetch(key, default = UNDEFINED, &block)
+      if @changes.key?(key)
+        @changes.fetch(key)
+      elsif default != UNDEFINED
+        if block_given?
+          @static.fetch(key, &block)
+        else
+          @static.fetch(key, default)
+        end
+      else
+        @static.fetch(key, &block)
+      end
+    end
+
+    def key?(key)
+      @changes.key?(key) || @static.key?(key)
+    end
+  end
+
+  # Alias for backwards compatibility
+  StaticRegisters = Registers
+end

lib/liquid/standardfilters.rb

@@ -1,10 +1,19 @@
 # frozen_string_literal: true
 
 require 'cgi'
+require 'base64'
 require 'bigdecimal'
 
 module Liquid
   module StandardFilters
+    MAX_I32 = (1 << 31) - 1
+    private_constant :MAX_I32
+
+    MIN_I64 = -(1 << 63)
+    MAX_I64 = (1 << 63) - 1
+    I64_RANGE = MIN_I64..MAX_I64
+    private_constant :MIN_I64, :MAX_I64, :I64_RANGE
+
     HTML_ESCAPE = {
       '&' => '&amp;',
       '>' => '&gt;',
@@ -16,43 +25,116 @@ module Liquid
     STRIP_HTML_BLOCKS       = Regexp.union(
       %r{<script.*?</script>}m,
       /<!--.*?-->/m,
-      %r{<style.*?</style>}m
+      %r{<style.*?</style>}m,
     )
     STRIP_HTML_TAGS = /<.*?>/m
 
-    # Return the size of an array or of an string
+    class << self
+      def try_coerce_encoding(input, encoding:)
+        original_encoding = input.encoding
+        if input.encoding != encoding
+          input.force_encoding(encoding)
+          unless input.valid_encoding?
+            input.force_encoding(original_encoding)
+          end
+        end
+        input
+      end
+    end
+
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category array
+    # @liquid_summary
+    #   Returns the size of a string or array.
+    # @liquid_description
+    #   The size of a string is the number of characters that the string includes. The size of an array is the number of items
+    #   in the array.
+    # @liquid_syntax variable | size
+    # @liquid_return [number]
     def size(input)
       input.respond_to?(:size) ? input.size : 0
     end
 
-    # convert an input string to DOWNCASE
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Converts a string to all lowercase characters.
+    # @liquid_syntax string | downcase
+    # @liquid_return [string]
     def downcase(input)
       input.to_s.downcase
     end
 
-    # convert an input string to UPCASE
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Converts a string to all uppercase characters.
+    # @liquid_syntax string | upcase
+    # @liquid_return [string]
     def upcase(input)
       input.to_s.upcase
     end
 
-    # capitalize words in the input centence
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Capitalizes the first word in a string and downcases the remaining characters.
+    # @liquid_syntax string | capitalize
+    # @liquid_return [string]
     def capitalize(input)
       input.to_s.capitalize
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Escapes special characters in HTML, such as `<>`, `'`, and `&`, and converts characters into escape sequences. The filter doesn't effect characters within the string that don’t have a corresponding escape sequence.".
+    # @liquid_syntax string | escape
+    # @liquid_return [string]
     def escape(input)
       CGI.escapeHTML(input.to_s) unless input.nil?
     end
     alias_method :h, :escape
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Escapes a string without changing characters that have already been escaped.
+    # @liquid_syntax string | escape_once
+    # @liquid_return [string]
     def escape_once(input)
       input.to_s.gsub(HTML_ESCAPE_ONCE_REGEXP, HTML_ESCAPE)
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Converts any URL-unsafe characters in a string to the
+    #   [percent-encoded](https://developer.mozilla.org/en-US/docs/Glossary/percent-encoding) equivalent.
+    # @liquid_description
+    #   > Note:
+    #   > Spaces are converted to a `+` character, instead of a percent-encoded character.
+    # @liquid_syntax string | url_encode
+    # @liquid_return [string]
     def url_encode(input)
       CGI.escape(input.to_s) unless input.nil?
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Decodes any [percent-encoded](https://developer.mozilla.org/en-US/docs/Glossary/percent-encoding) characters
+    #   in a string.
+    # @liquid_syntax string | url_decode
+    # @liquid_return [string]
     def url_decode(input)
       return if input.nil?
 
@@ -62,18 +144,96 @@ module Liquid
       result
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Encodes a string to [Base64 format](https://developer.mozilla.org/en-US/docs/Glossary/Base64).
+    # @liquid_syntax string | base64_encode
+    # @liquid_return [string]
+    def base64_encode(input)
+      Base64.strict_encode64(input.to_s)
+    end
+
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Decodes a string in [Base64 format](https://developer.mozilla.org/en-US/docs/Glossary/Base64).
+    # @liquid_syntax string | base64_decode
+    # @liquid_return [string]
+    def base64_decode(input)
+      input = input.to_s
+      StandardFilters.try_coerce_encoding(Base64.strict_decode64(input), encoding: input.encoding)
+    rescue ::ArgumentError
+      raise Liquid::ArgumentError, "invalid base64 provided to base64_decode"
+    end
+
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Encodes a string to URL-safe [Base64 format](https://developer.mozilla.org/en-US/docs/Glossary/Base64).
+    # @liquid_syntax string | base64_url_safe_encode
+    # @liquid_return [string]
+    def base64_url_safe_encode(input)
+      Base64.urlsafe_encode64(input.to_s)
+    end
+
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Decodes a string in URL-safe [Base64 format](https://developer.mozilla.org/en-US/docs/Glossary/Base64).
+    # @liquid_syntax string | base64_url_safe_decode
+    # @liquid_return [string]
+    def base64_url_safe_decode(input)
+      input = input.to_s
+      StandardFilters.try_coerce_encoding(Base64.urlsafe_decode64(input), encoding: input.encoding)
+    rescue ::ArgumentError
+      raise Liquid::ArgumentError, "invalid base64 provided to base64_url_safe_decode"
+    end
+
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Returns a substring or series of array items, starting at a given 0-based index.
+    # @liquid_description
+    #   By default, the substring has a length of one character, and the array series has one array item. However, you can
+    #   provide a second parameter to specify the number of characters or array items.
+    # @liquid_syntax string | slice
+    # @liquid_return [string]
     def slice(input, offset, length = nil)
       offset = Utils.to_integer(offset)
       length = length ? Utils.to_integer(length) : 1
 
-      if input.is_a?(Array)
-        input.slice(offset, length) || []
-      else
-        input.to_s.slice(offset, length) || ''
+      begin
+        if input.is_a?(Array)
+          input.slice(offset, length) || []
+        else
+          input.to_s.slice(offset, length) || ''
+        end
+      rescue RangeError
+        if I64_RANGE.cover?(length) && I64_RANGE.cover?(offset)
+          raise # unexpected error
+        end
+        offset = offset.clamp(I64_RANGE)
+        length = length.clamp(I64_RANGE)
+        retry
       end
     end
 
-    # Truncate a string down to x characters
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Truncates a string down to a given number of characters.
+    # @liquid_description
+    #   If the specified number of characters is less than the length of the string, then an ellipsis (`...`) is appended to
+    #   the truncated string. The ellipsis is included in the character count of the truncated string.
+    # @liquid_syntax string | truncate: number
+    # @liquid_return [string]
     def truncate(input, length = 50, truncate_string = "...")
       return if input.nil?
       input_str = input.to_s
@@ -87,38 +247,90 @@ module Liquid
       input_str.length > length ? input_str[0...l].concat(truncate_string_str) : input_str
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Truncates a string down to a given number of words.
+    # @liquid_description
+    #   If the specified number of words is less than the number of words in the string, then an ellipsis (`...`) is appended to
+    #   the truncated string.
+    #
+    #   > Caution:
+    #   > HTML tags are treated as words, so you should strip any HTML from truncated content. If you don't strip HTML, then
+    #   > closing HTML tags can be removed, which can result in unexpected behavior.
+    # @liquid_syntax string | truncatewords: number
+    # @liquid_return [string]
     def truncatewords(input, words = 15, truncate_string = "...")
       return if input.nil?
-      wordlist = input.to_s.split
-      words    = Utils.to_integer(words)
+      input = input.to_s
+      words = Utils.to_integer(words)
+      words = 1 if words <= 0
 
-      l = words - 1
-      l = 0 if l < 0
+      wordlist = begin
+        input.split(" ", words + 1)
+      rescue RangeError
+        # integer too big for String#split, but we can semantically assume no truncation is needed
+        return input if words + 1 > MAX_I32
+        raise # unexpected error
+      end
+      return input if wordlist.length <= words
 
-      wordlist.length > l ? wordlist[0..l].join(" ").concat(truncate_string.to_s) : input
+      wordlist.pop
+      wordlist.join(" ").concat(truncate_string.to_s)
     end
 
-    # Split input string into an array of substrings separated by given pattern.
-    #
-    # Example:
-    #   <div class="summary">{{ post | split '//' | first }}</div>
-    #
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Splits a string into an array of substrings based on a given separator.
+    # @liquid_syntax string | split: string
+    # @liquid_return [array[string]]
     def split(input, pattern)
       input.to_s.split(pattern.to_s)
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Strips all whitespace from the left and right of a string.
+    # @liquid_syntax string | strip
+    # @liquid_return [string]
     def strip(input)
       input.to_s.strip
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Strips all whitespace from the left of a string.
+    # @liquid_syntax string | lstrip
+    # @liquid_return [string]
     def lstrip(input)
       input.to_s.lstrip
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Strips all whitespace from the right of a string.
+    # @liquid_syntax string | rstrip
+    # @liquid_return [string]
     def rstrip(input)
       input.to_s.rstrip
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Strips all HTML tags from a string.
+    # @liquid_syntax string | strip_html
+    # @liquid_return [string]
     def strip_html(input)
       empty  = ''
       result = input.to_s.gsub(STRIP_HTML_BLOCKS, empty)
@@ -126,18 +338,35 @@ module Liquid
       result
     end
 
-    # Remove all newlines from the string
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Strips all newline characters (line breaks) from a string.
+    # @liquid_syntax string | strip_newlines
+    # @liquid_return [string]
     def strip_newlines(input)
       input.to_s.gsub(/\r?\n/, '')
     end
 
-    # Join elements of the array with certain character between them
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category array
+    # @liquid_summary
+    #   Combines all of the items in an array into a single string, separated by a space.
+    # @liquid_syntax array | join
+    # @liquid_return [string]
     def join(input, glue = ' ')
       InputIterator.new(input, context).join(glue)
     end
 
-    # Sort elements of the array
-    # provide optional property with which to sort an array of hashes or drops
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category array
+    # @liquid_summary
+    #   Sorts the items in an array in case-sensitive alphabetical, or numerical, order.
+    # @liquid_syntax array | sort
+    # @liquid_return [array[untyped]]
     def sort(input, property = nil)
       ary = InputIterator.new(input, context)
 
@@ -156,8 +385,17 @@ module Liquid
       end
     end
 
-    # Sort elements of an array ignoring case if strings
-    # provide optional property with which to sort an array of hashes or drops
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category array
+    # @liquid_summary
+    #   Sorts the items in an array in case-insensitive alphabetical order.
+    # @liquid_description
+    #   > Caution:
+    #   > You shouldn't use the `sort_natural` filter to sort numerical values. When comparing items an array, each item is converted to a
+    #   > string, so sorting on numerical values can lead to unexpected results.
+    # @liquid_syntax array | sort_natural
+    # @liquid_return [array[untyped]]
     def sort_natural(input, property = nil)
       ary = InputIterator.new(input, context)
 
@@ -176,30 +414,48 @@ module Liquid
       end
     end
 
-    # Filter the elements of an array to those with a certain property value.
-    # By default the target is any truthy value.
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category array
+    # @liquid_summary
+    #   Filters an array to include only items with a specific property value.
+    # @liquid_description
+    #   This requires you to provide both the property name and the associated value.
+    # @liquid_syntax array | where: string, string
+    # @liquid_return [array[untyped]]
     def where(input, property, target_value = nil)
       ary = InputIterator.new(input, context)
 
       if ary.empty?
         []
-      elsif ary.first.respond_to?(:[]) && target_value.nil?
-        begin
-          ary.select { |item| item[property] }
+      elsif target_value.nil?
+        ary.select do |item|
+          item[property]
         rescue TypeError
           raise_property_error(property)
+        rescue NoMethodError
+          return nil unless item.respond_to?(:[])
+          raise
         end
-      elsif ary.first.respond_to?(:[])
-        begin
-          ary.select { |item| item[property] == target_value }
+      else
+        ary.select do |item|
+          item[property] == target_value
         rescue TypeError
           raise_property_error(property)
+        rescue NoMethodError
+          return nil unless item.respond_to?(:[])
+          raise
         end
       end
     end
 
-    # Remove duplicate elements from an array
-    # provide optional property with which to determine uniqueness
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category array
+    # @liquid_summary
+    #   Removes any duplicate items in an array.
+    # @liquid_syntax array | uniq
+    # @liquid_return [array[untyped]]
     def uniq(input, property = nil)
       ary = InputIterator.new(input, context)
 
@@ -207,22 +463,37 @@ module Liquid
         ary.uniq
       elsif ary.empty? # The next two cases assume a non-empty array.
         []
-      elsif ary.first.respond_to?(:[])
-        begin
-          ary.uniq { |a| a[property] }
+      else
+        ary.uniq do |item|
+          item[property]
         rescue TypeError
           raise_property_error(property)
+        rescue NoMethodError
+          return nil unless item.respond_to?(:[])
+          raise
         end
       end
     end
 
-    # Reverse the elements of an array
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category array
+    # @liquid_summary
+    #   Reverses the order of the items in an array.
+    # @liquid_syntax array | reverse
+    # @liquid_return [array[untyped]]
     def reverse(input)
       ary = InputIterator.new(input, context)
       ary.reverse
     end
 
-    # map/collect on a given property
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category array
+    # @liquid_summary
+    #   Creates an array of values from a specific property of the items in an array.
+    # @liquid_syntax array | map: string
+    # @liquid_return [array[untyped]]
     def map(input, property)
       InputIterator.new(input, context).map do |e|
         e = e.call if e.is_a?(Proc)
@@ -238,8 +509,13 @@ module Liquid
       raise_property_error(property)
     end
 
-    # Remove nils within an array
-    # provide optional property with which to check for nil
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category array
+    # @liquid_summary
+    #   Removes any `nil` items from an array.
+    # @liquid_syntax array | compact
+    # @liquid_return [array[untyped]]
     def compact(input, property = nil)
       ary = InputIterator.new(input, context)
 
@@ -247,40 +523,116 @@ module Liquid
         ary.compact
       elsif ary.empty? # The next two cases assume a non-empty array.
         []
-      elsif ary.first.respond_to?(:[])
-        begin
-          ary.reject { |a| a[property].nil? }
+      else
+        ary.reject do |item|
+          item[property].nil?
         rescue TypeError
           raise_property_error(property)
+        rescue NoMethodError
+          return nil unless item.respond_to?(:[])
+          raise
         end
       end
     end
 
-    # Replace occurrences of a string with another
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Replaces any instance of a substring inside a string with a given string.
+    # @liquid_syntax string | replace: string, string
+    # @liquid_return [string]
     def replace(input, string, replacement = '')
       input.to_s.gsub(string.to_s, replacement.to_s)
     end
 
-    # Replace the first occurrences of a string with another
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Replaces the first instance of a substring inside a string with a given string.
+    # @liquid_syntax string | replace_first: string, string
+    # @liquid_return [string]
     def replace_first(input, string, replacement = '')
       input.to_s.sub(string.to_s, replacement.to_s)
     end
 
-    # remove a substring
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Replaces the last instance of a substring inside a string with a given string.
+    # @liquid_syntax string | replace_last: string, string
+    # @liquid_return [string]
+    def replace_last(input, string, replacement)
+      input = input.to_s
+      string = string.to_s
+      replacement = replacement.to_s
+
+      start_index = input.rindex(string)
+
+      return input unless start_index
+
+      output = input.dup
+      output[start_index, string.length] = replacement
+      output
+    end
+
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Removes any instance of a substring inside a string.
+    # @liquid_syntax string | remove: string
+    # @liquid_return [string]
     def remove(input, string)
-      input.to_s.gsub(string.to_s, '')
+      replace(input, string, '')
     end
 
-    # remove the first occurrences of a substring
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Removes the first instance of a substring inside a string.
+    # @liquid_syntax string | remove_first: string
+    # @liquid_return [string]
     def remove_first(input, string)
-      input.to_s.sub(string.to_s, '')
+      replace_first(input, string, '')
     end
 
-    # add one string to another
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Removes the last instance of a substring inside a string.
+    # @liquid_syntax string | remove_last: string
+    # @liquid_return [string]
+    def remove_last(input, string)
+      replace_last(input, string, '')
+    end
+
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Adds a given string to the end of a string.
+    # @liquid_syntax string | append: string
+    # @liquid_return [string]
     def append(input, string)
       input.to_s + string.to_s
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category array
+    # @liquid_summary
+    #   Concatenates (combines) two arrays.
+    # @liquid_description
+    #   > Note:
+    #   > The `concat` filter won't filter out duplicates. If you want to remove duplicates, then you need to use the
+    #   > [`uniq` filter](/docs/api/liquid/filters/uniq).
+    # @liquid_syntax array | concat: array
+    # @liquid_return [array[untyped]]
     def concat(input, array)
       unless array.respond_to?(:to_ary)
         raise ArgumentError, "concat filter requires an array argument"
@@ -288,14 +640,26 @@ module Liquid
       InputIterator.new(input, context).concat(array)
     end
 
-    # prepend a string to another
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Adds a given string to the beginning of a string.
+    # @liquid_syntax string | prepend: string
+    # @liquid_return [string]
     def prepend(input, string)
       string.to_s + input.to_s
     end
 
-    # Add <br /> tags in front of all newlines in input string
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category string
+    # @liquid_summary
+    #   Converts newlines (`\n`) in a string to HTML line breaks (`<br>`).
+    # @liquid_syntax string | newline_to_br
+    # @liquid_return [string]
     def newline_to_br(input)
-      input.to_s.gsub(/\n/, "<br />\n")
+      input.to_s.gsub(/\r?\n/, "<br />\n")
     end
 
     # Reformat a date using Ruby's core Time#strftime( string ) -> string
@@ -337,58 +701,106 @@ module Liquid
       date.strftime(format.to_s)
     end
 
-    # Get the first element of the passed in array
-    #
-    # Example:
-    #    {{ product.images | first | to_img }}
-    #
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category array
+    # @liquid_summary
+    #   Returns the first item in an array.
+    # @liquid_syntax array | first
+    # @liquid_return [untyped]
     def first(array)
       array.first if array.respond_to?(:first)
     end
 
-    # Get the last element of the passed in array
-    #
-    # Example:
-    #    {{ product.images | last | to_img }}
-    #
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category array
+    # @liquid_summary
+    #   Returns the last item in an array.
+    # @liquid_syntax array | last
+    # @liquid_return [untyped]
     def last(array)
       array.last if array.respond_to?(:last)
     end
 
-    # absolute value
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category math
+    # @liquid_summary
+    #   Returns the absolute value of a number.
+    # @liquid_syntax number | abs
+    # @liquid_return [number]
     def abs(input)
       result = Utils.to_number(input).abs
       result.is_a?(BigDecimal) ? result.to_f : result
     end
 
-    # addition
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category math
+    # @liquid_summary
+    #   Adds two numbers.
+    # @liquid_syntax number | plus: number
+    # @liquid_return [number]
     def plus(input, operand)
       apply_operation(input, operand, :+)
     end
 
-    # subtraction
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category math
+    # @liquid_summary
+    #   Subtracts a given number from another number.
+    # @liquid_syntax number | minus: number
+    # @liquid_return [number]
     def minus(input, operand)
       apply_operation(input, operand, :-)
     end
 
-    # multiplication
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category math
+    # @liquid_summary
+    #   Multiplies a number by a given number.
+    # @liquid_syntax number | times: number
+    # @liquid_return [number]
     def times(input, operand)
       apply_operation(input, operand, :*)
     end
 
-    # division
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category math
+    # @liquid_summary
+    #   Divides a number by a given number. The `divided_by` filter produces a result of the same type as the divisor. This means if you divide by an integer, the result will be an integer, and if you divide by a float, the result will be a float.
+    # @liquid_syntax number | divided_by: number
+    # @liquid_return [number]
     def divided_by(input, operand)
       apply_operation(input, operand, :/)
     rescue ::ZeroDivisionError => e
       raise Liquid::ZeroDivisionError, e.message
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category math
+    # @liquid_summary
+    #   Returns the remainder of dividing a number by a given number.
+    # @liquid_syntax number | modulo: number
+    # @liquid_return [number]
     def modulo(input, operand)
       apply_operation(input, operand, :%)
     rescue ::ZeroDivisionError => e
       raise Liquid::ZeroDivisionError, e.message
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category math
+    # @liquid_summary
+    #   Rounds a number to the nearest integer.
+    # @liquid_syntax number | round
+    # @liquid_return [number]
     def round(input, n = 0)
       result = Utils.to_number(input).round(Utils.to_number(n))
       result = result.to_f if result.is_a?(BigDecimal)
@@ -398,18 +810,39 @@ module Liquid
       raise Liquid::FloatDomainError, e.message
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category math
+    # @liquid_summary
+    #   Rounds a number up to the nearest integer.
+    # @liquid_syntax number | ceil
+    # @liquid_return [number]
     def ceil(input)
       Utils.to_number(input).ceil.to_i
     rescue ::FloatDomainError => e
       raise Liquid::FloatDomainError, e.message
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category math
+    # @liquid_summary
+    #   Rounds a number down to the nearest integer.
+    # @liquid_syntax number | floor
+    # @liquid_return [number]
     def floor(input)
       Utils.to_number(input).floor.to_i
     rescue ::FloatDomainError => e
       raise Liquid::FloatDomainError, e.message
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category math
+    # @liquid_summary
+    #   Limits a number to a minimum value.
+    # @liquid_syntax number | at_least
+    # @liquid_return [number]
     def at_least(input, n)
       min_value = Utils.to_number(n)
 
@@ -418,6 +851,13 @@ module Liquid
       result.is_a?(BigDecimal) ? result.to_f : result
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category math
+    # @liquid_summary
+    #   Limits a number to a maximum value.
+    # @liquid_syntax number | at_most
+    # @liquid_return [number]
     def at_most(input, n)
       max_value = Utils.to_number(n)
 
@@ -426,22 +866,54 @@ module Liquid
       result.is_a?(BigDecimal) ? result.to_f : result
     end
 
-    # Set a default value when the input is nil, false or empty
-    #
-    # Example:
-    #    {{ product.title | default: "No Title" }}
-    #
-    # Use `allow_false` when an input should only be tested against nil or empty and not false.
-    #
-    # Example:
-    #    {{ product.title | default: "No Title", allow_false: true }}
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category default
+    # @liquid_summary
+    #   Sets a default value for any variable whose value is one of the following:
     #
+    #   - [`empty`](/docs/api/liquid/basics#empty)
+    #   - [`false`](/docs/api/liquid/basics#truthy-and-falsy)
+    #   - [`nil`](/docs/api/liquid/basics#nil)
+    # @liquid_syntax variable | default: variable
+    # @liquid_return [untyped]
+    # @liquid_optional_param allow_false: [boolean] Whether to use false values instead of the default.
     def default(input, default_value = '', options = {})
       options = {} unless options.is_a?(Hash)
-      false_check = options['allow_false'] ? input.nil? : !input
+      false_check = options['allow_false'] ? input.nil? : !Liquid::Utils.to_liquid_value(input)
       false_check || (input.respond_to?(:empty?) && input.empty?) ? default_value : input
     end
 
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category array
+    # @liquid_summary
+    #   Returns the sum of all elements in an array.
+    # @liquid_syntax array | sum
+    # @liquid_return [number]
+    def sum(input, property = nil)
+      ary = InputIterator.new(input, context)
+      return 0 if ary.empty?
+
+      values_for_sum = ary.map do |item|
+        if property.nil?
+          item
+        elsif item.respond_to?(:[])
+          item[property]
+        else
+          0
+        end
+      rescue TypeError
+        raise_property_error(property)
+      end
+
+      result = InputIterator.new(values_for_sum, context).sum do |item|
+        Utils.to_number(item)
+      end
+
+      result.is_a?(BigDecimal) ? result.to_f : result
+    end
+
     private
 
     attr_reader :context
@@ -456,16 +928,24 @@ module Liquid
     end
 
     def nil_safe_compare(a, b)
-      if !a.nil? && !b.nil?
-        a <=> b
+      result = a <=> b
+
+      if result
+        result
+      elsif a.nil?
+        1
+      elsif b.nil?
+        -1
       else
-        a.nil? ? 1 : -1
+        raise Liquid::ArgumentError, "cannot sort values of incompatible types"
       end
     end
 
     def nil_safe_casecmp(a, b)
       if !a.nil? && !b.nil?
         a.to_s.casecmp(b.to_s)
+      elsif a.nil? && b.nil?
+        0
       else
         a.nil? ? 1 : -1
       end
@@ -514,12 +994,11 @@ module Liquid
 
       def each
         @input.each do |e|
+          e = e.respond_to?(:to_liquid) ? e.to_liquid : e
           e.context = @context if e.respond_to?(:context=)
-          yield(e.respond_to?(:to_liquid) ? e.to_liquid : e)
+          yield(e)
         end
       end
     end
   end
-
-  Template.register_filter(StandardFilters)
 end

lib/liquid/static_registers.rb

@@ -1,44 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  class StaticRegisters
-    attr_reader :static
-
-    def initialize(registers = {})
-      @static    = registers.is_a?(StaticRegisters) ? registers.static : registers
-      @registers = {}
-    end
-
-    def []=(key, value)
-      @registers[key] = value
-    end
-
-    def [](key)
-      if @registers.key?(key)
-        @registers[key]
-      else
-        @static[key]
-      end
-    end
-
-    def delete(key)
-      @registers.delete(key)
-    end
-
-    UNDEFINED = Object.new
-
-    def fetch(key, default = UNDEFINED, &block)
-      if @registers.key?(key)
-        @registers.fetch(key)
-      elsif default != UNDEFINED
-        @static.fetch(key, default, &block)
-      else
-        @static.fetch(key, &block)
-      end
-    end
-
-    def key?(key)
-      @registers.key?(key) || @static.key?(key)
-    end
-  end
-end

lib/liquid/strainer_factory.rb

@@ -1,36 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  # StrainerFactory is the factory for the filters system.
-  module StrainerFactory
-    extend self
-
-    def add_global_filter(filter)
-      strainer_class_cache.clear
-      global_filters << filter
-    end
-
-    def create(context, filters = [])
-      strainer_from_cache(filters).new(context)
-    end
-
-    private
-
-    def global_filters
-      @global_filters ||= []
-    end
-
-    def strainer_from_cache(filters)
-      strainer_class_cache[filters] ||= begin
-        klass = Class.new(StrainerTemplate)
-        global_filters.each { |f| klass.add_filter(f) }
-        filters.each { |f| klass.add_filter(f) }
-        klass
-      end
-    end
-
-    def strainer_class_cache
-      @strainer_class_cache ||= {}
-    end
-  end
-end

lib/liquid/strainer_template.rb

@@ -31,6 +31,15 @@ module Liquid
         filter_methods.include?(method.to_s)
       end
 
+      def inherited(subclass)
+        super
+        subclass.instance_variable_set(:@filter_methods, @filter_methods.dup)
+      end
+
+      def filter_method_names
+        filter_methods.map(&:to_s).to_a
+      end
+
       private
 
       def filter_methods

lib/liquid/tablerowloop_drop.rb

@@ -1,6 +1,11 @@
 # frozen_string_literal: true
 
 module Liquid
+  # @liquid_public_docs
+  # @liquid_type object
+  # @liquid_name tablerowloop
+  # @liquid_summary
+  #   Information about a parent [`tablerow` loop](/docs/api/liquid/tags/tablerow).
   class TablerowloopDrop < Drop
     def initialize(length, cols)
       @length = length
@@ -10,40 +15,92 @@ module Liquid
       @index  = 0
     end
 
-    attr_reader :length, :col, :row
+    # @liquid_public_docs
+    # @liquid_summary
+    #   The total number of iterations in the loop.
+    # @liquid_return [number]
+    attr_reader :length
 
+    # @liquid_public_docs
+    # @liquid_summary
+    #   The 1-based index of the current column.
+    # @liquid_return [number]
+    attr_reader :col
+
+    # @liquid_public_docs
+    # @liquid_summary
+    #   The 1-based index of current row.
+    # @liquid_return [number]
+    attr_reader :row
+
+    # @liquid_public_docs
+    # @liquid_summary
+    #   The 1-based index of the current iteration.
+    # @liquid_return [number]
     def index
       @index + 1
     end
 
+    # @liquid_public_docs
+    # @liquid_summary
+    #   The 0-based index of the current iteration.
+    # @liquid_return [number]
     def index0
       @index
     end
 
+    # @liquid_public_docs
+    # @liquid_summary
+    #   The 0-based index of the current column.
+    # @liquid_return [number]
     def col0
       @col - 1
     end
 
+    # @liquid_public_docs
+    # @liquid_summary
+    #   The 1-based index of the current iteration, in reverse order.
+    # @liquid_return [number]
     def rindex
       @length - @index
     end
 
+    # @liquid_public_docs
+    # @liquid_summary
+    #   The 0-based index of the current iteration, in reverse order.
+    # @liquid_return [number]
     def rindex0
       @length - @index - 1
     end
 
+    # @liquid_public_docs
+    # @liquid_summary
+    #   Returns `true` if the current iteration is the first. Returns `false` if not.
+    # @liquid_return [boolean]
     def first
       @index == 0
     end
 
+    # @liquid_public_docs
+    # @liquid_summary
+    #   Returns `true` if the current iteration is the last. Returns `false` if not.
+    # @liquid_return [boolean]
     def last
       @index == @length - 1
     end
 
+    # @liquid_public_docs
+    # @liquid_summary
+    #   Returns `true` if the current column is the first in the row. Returns `false` if not.
+    # @liquid_return [boolean]
     def col_first
       @col == 1
     end
 
+    # @liquid_public_docs
+    # @liquid_summary
+    #   Returns `true` if the current column is the last in the row. Returns `false` if not.
+    # @liquid_return [boolean]
     def col_last
       @col == @cols
     end

lib/liquid/tag.rb

@@ -1,5 +1,8 @@
 # frozen_string_literal: true
 
+require 'liquid/tag/disabler'
+require 'liquid/tag/disableable'
+
 module Liquid
   class Tag
     attr_reader :nodelist, :tag_name, :line_number, :parse_context
@@ -14,12 +17,18 @@ module Liquid
       end
 
       def disable_tags(*tag_names)
-        @disabled_tags ||= []
-        @disabled_tags.concat(tag_names)
+        tag_names += disabled_tags
+        define_singleton_method(:disabled_tags) { tag_names }
         prepend(Disabler)
       end
 
       private :new
+
+      protected
+
+      def disabled_tags
+        []
+      end
     end
 
     def initialize(tag_name, markup, parse_context)
@@ -48,7 +57,8 @@ module Liquid
     # of the `render_to_output_buffer` method will become the default and the `render`
     # method will be removed.
     def render_to_output_buffer(context, output)
-      output << render(context)
+      render_result = render(context)
+      output << render_result if render_result
       output
     end
 

lib/liquid/tag/disabler.rb

@@ -3,14 +3,6 @@
 module Liquid
   class Tag
     module Disabler
-      module ClassMethods
-        attr_reader :disabled_tags
-      end
-
-      def self.prepended(base)
-        base.extend(ClassMethods)
-      end
-
       def render_to_output_buffer(context, output)
         context.with_disabled_tags(self.class.disabled_tags) do
           super

lib/liquid/tags.rb

@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+require_relative "tags/table_row"
+require_relative "tags/echo"
+require_relative "tags/if"
+require_relative "tags/break"
+require_relative "tags/inline_comment"
+require_relative "tags/for"
+require_relative "tags/assign"
+require_relative "tags/ifchanged"
+require_relative "tags/case"
+require_relative "tags/include"
+require_relative "tags/continue"
+require_relative "tags/capture"
+require_relative "tags/decrement"
+require_relative "tags/unless"
+require_relative "tags/increment"
+require_relative "tags/comment"
+require_relative "tags/raw"
+require_relative "tags/render"
+require_relative "tags/cycle"
+
+module Liquid
+  module Tags
+    STANDARD_TAGS = {
+      'cycle' => Cycle,
+      'render' => Render,
+      'raw' => Raw,
+      'comment' => Comment,
+      'increment' => Increment,
+      'unless' => Unless,
+      'decrement' => Decrement,
+      'capture' => Capture,
+      'continue' => Continue,
+      'include' => Include,
+      'case' => Case,
+      'ifchanged' => Ifchanged,
+      'assign' => Assign,
+      'for' => For,
+      '#' => InlineComment,
+      'break' => Break,
+      'if' => If,
+      'echo' => Echo,
+      'tablerow' => TableRow,
+    }.freeze
+  end
+end

lib/liquid/tags/assign.rb

@@ -1,14 +1,18 @@
 # frozen_string_literal: true
 
 module Liquid
-  # Assign sets a variable in your template.
-  #
-  #   {% assign foo = 'monkey' %}
-  #
-  # You can then use the variable later in the page.
-  #
-  #  {{ foo }}
-  #
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category variable
+  # @liquid_name assign
+  # @liquid_summary
+  #   Creates a new variable.
+  # @liquid_description
+  #   You can create variables of any [basic type](/docs/api/liquid/basics#types), [object](/docs/api/liquid/objects), or object property.
+  # @liquid_syntax
+  #   {% assign variable_name = value %}
+  # @liquid_syntax_keyword variable_name The name of the variable being created.
+  # @liquid_syntax_keyword value The value you want to assign to the variable.
   class Assign < Tag
     Syntax = /(#{VariableSignature}+)\s*=\s*(.*)\s*/om
 
@@ -68,6 +72,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_tag('assign', Assign)
 end

lib/liquid/tags/break.rb

@@ -10,6 +10,14 @@ module Liquid
   #      {% endif %}
   #    {% endfor %}
   #
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category iteration
+  # @liquid_name break
+  # @liquid_summary
+  #   Stops a [`for` loop](/docs/api/liquid/tags/for) from iterating.
+  # @liquid_syntax
+  #   {% break %}
   class Break < Tag
     INTERRUPT = BreakInterrupt.new.freeze
 
@@ -18,6 +26,4 @@ module Liquid
       output
     end
   end
-
-  Template.register_tag('break', Break)
 end

lib/liquid/tags/capture.rb

@@ -1,17 +1,20 @@
 # frozen_string_literal: true
 
 module Liquid
-  # Capture stores the result of a block into a variable without rendering it inplace.
-  #
-  #   {% capture heading %}
-  #     Monkeys!
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category variable
+  # @liquid_name capture
+  # @liquid_summary
+  #   Creates a new variable with a string value.
+  # @liquid_description
+  #   You can create complex strings with Liquid logic and variables.
+  # @liquid_syntax
+  #   {% capture variable %}
+  #     value
   #   {% endcapture %}
-  #   ...
-  #   <h1>{{ heading }}</h1>
-  #
-  # Capture is useful for saving content for use later in your template, such as
-  # in a sidebar or footer.
-  #
+  # @liquid_syntax_keyword variable The name of the variable being created.
+  # @liquid_syntax_keyword value The value you want to assign to the variable.
   class Capture < Block
     Syntax = /(#{VariableSignature}+)/o
 
@@ -36,6 +39,4 @@ module Liquid
       true
     end
   end
-
-  Template.register_tag('capture', Capture)
 end

lib/liquid/tags/case.rb

@@ -1,6 +1,27 @@
 # frozen_string_literal: true
 
 module Liquid
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category conditional
+  # @liquid_name case
+  # @liquid_summary
+  #   Renders a specific expression depending on the value of a specific variable.
+  # @liquid_syntax
+  #   {% case variable %}
+  #     {% when first_value %}
+  #       first_expression
+  #     {% when second_value %}
+  #       second_expression
+  #     {% else %}
+  #       third_expression
+  #   {% endcase %}
+  # @liquid_syntax_keyword variable The name of the variable you want to base your case statement on.
+  # @liquid_syntax_keyword first_value A specific value to check for.
+  # @liquid_syntax_keyword second_value A specific value to check for.
+  # @liquid_syntax_keyword first_expression An expression to be rendered when the variable's value matches `first_value`.
+  # @liquid_syntax_keyword second_expression An expression to be rendered when the variable's value matches `second_value`.
+  # @liquid_syntax_keyword third_expression An expression to be rendered when the variable's value has no match.
   class Case < Block
     Syntax     = /(#{QuotedFragment})/o
     WhenSyntax = /(#{QuotedFragment})(?:(?:\s+or\s+|\s*\,\s*)(#{QuotedFragment}.*))?/om
@@ -52,7 +73,14 @@ module Liquid
       @blocks.each do |block|
         if block.else?
           block.attachment.render_to_output_buffer(context, output) if execute_else_block
-        elsif block.evaluate(context)
+          next
+        end
+
+        result = Liquid::Utils.to_liquid_value(
+          block.evaluate(context),
+        )
+
+        if result
           execute_else_block = false
           block.attachment.render_to_output_buffer(context, output)
         end
@@ -95,6 +123,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_tag('case', Case)
 end

lib/liquid/tags/comment.rb

@@ -1,6 +1,19 @@
 # frozen_string_literal: true
 
 module Liquid
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category syntax
+  # @liquid_name comment
+  # @liquid_summary
+  #   Prevents an expression from being rendered or output.
+  # @liquid_description
+  #   Any text inside `comment` tags won't be output, and any Liquid code will be parsed, but not executed.
+  # @liquid_syntax
+  #   {% comment %}
+  #     content
+  #   {% endcomment %}
+  # @liquid_syntax_keyword content The content of the comment.
   class Comment < Block
     def render_to_output_buffer(_context, output)
       output
@@ -12,7 +25,64 @@ module Liquid
     def blank?
       true
     end
-  end
 
-  Template.register_tag('comment', Comment)
+    private
+
+    def parse_body(body, tokenizer)
+      if parse_context.depth >= MAX_DEPTH
+        raise StackLevelError, "Nesting too deep"
+      end
+
+      parse_context.depth += 1
+      comment_tag_depth = 1
+
+      begin
+        # Consume tokens without creating child nodes.
+        # The children tag doesn't require to be a valid Liquid except the comment and raw tag.
+        # The child comment and raw tag must be closed.
+        while (token = tokenizer.send(:shift))
+          tag_name = if tokenizer.for_liquid_tag
+            next if token.empty? || token.match?(BlockBody::WhitespaceOrNothing)
+
+            tag_name_match = BlockBody::LiquidTagToken.match(token)
+
+            next if tag_name_match.nil?
+
+            tag_name_match[1]
+          else
+            token =~ BlockBody::FullToken
+            Regexp.last_match(2)
+          end
+
+          case tag_name
+          when "raw"
+            parse_raw_tag_body(tokenizer)
+          when "comment"
+            comment_tag_depth += 1
+          when "endcomment"
+            comment_tag_depth -= 1
+          end
+
+          if comment_tag_depth.zero?
+            parse_context.trim_whitespace = (token[-3] == WhitespaceControl) unless tokenizer.for_liquid_tag
+            return false
+          end
+        end
+
+        raise_tag_never_closed(block_name)
+      ensure
+        parse_context.depth -= 1
+      end
+
+      false
+    end
+
+    def parse_raw_tag_body(tokenizer)
+      while (token = tokenizer.send(:shift))
+        return if token =~ BlockBody::FullTokenPossiblyInvalid && "endraw" == Regexp.last_match(2)
+      end
+
+      raise_tag_never_closed("raw")
+    end
+  end
 end

lib/liquid/tags/continue.rb

@@ -1,15 +1,14 @@
 # frozen_string_literal: true
 
 module Liquid
-  # Continue tag to be used to break out of a for loop.
-  #
-  # == Basic Usage:
-  #    {% for item in collection %}
-  #      {% if item.condition %}
-  #        {% continue %}
-  #      {% endif %}
-  #    {% endfor %}
-  #
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category iteration
+  # @liquid_name continue
+  # @liquid_summary
+  #   Causes a [`for` loop](/docs/api/liquid/tags/for) to skip to the next iteration.
+  # @liquid_syntax
+  #   {% continue %}
   class Continue < Tag
     INTERRUPT = ContinueInterrupt.new.freeze
 
@@ -18,6 +17,4 @@ module Liquid
       output
     end
   end
-
-  Template.register_tag('continue', Continue)
 end

lib/liquid/tags/cycle.rb

@@ -1,18 +1,19 @@
 # frozen_string_literal: true
 
 module Liquid
-  # Cycle is usually used within a loop to alternate between values, like colors or DOM classes.
-  #
-  #   {% for item in items %}
-  #     <div class="{% cycle 'red', 'green', 'blue' %}"> {{ item }} </div>
-  #   {% end %}
-  #
-  #    <div class="red"> Item one </div>
-  #    <div class="green"> Item two </div>
-  #    <div class="blue"> Item three </div>
-  #    <div class="red"> Item four </div>
-  #    <div class="green"> Item five</div>
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category iteration
+  # @liquid_name cycle
+  # @liquid_summary
+  #   Loops through a group of strings and outputs them one at a time for each iteration of a [`for` loop](/docs/api/liquid/tags/for).
+  # @liquid_description
+  #   The `cycle` tag must be used inside a `for` loop.
   #
+  #   > Tip:
+  #   > Use the `cycle` tag to output text in a predictable pattern. For example, to apply odd/even classes to rows in a table.
+  # @liquid_syntax
+  #   {% cycle string, string, ... %}
   class Cycle < Tag
     SimpleSyntax = /\A#{QuotedFragment}+/o
     NamedSyntax  = /\A(#{QuotedFragment})\s*\:\s*(.*)/om
@@ -25,14 +26,20 @@ module Liquid
       when NamedSyntax
         @variables = variables_from_string(Regexp.last_match(2))
         @name      = parse_expression(Regexp.last_match(1))
+        @is_named = true
       when SimpleSyntax
         @variables = variables_from_string(markup)
         @name      = @variables.to_s
+        @is_named = !@name.match?(/\w+:0x\h{8}/)
       else
         raise SyntaxError, options[:locale].t("errors.syntax.cycle")
       end
     end
 
+    def named?
+      @is_named
+    end
+
     def render_to_output_buffer(context, output)
       context.registers[:cycle] ||= {}
 
@@ -61,7 +68,13 @@ module Liquid
     def variables_from_string(markup)
       markup.split(',').collect do |var|
         var =~ /\s*(#{QuotedFragment})\s*/o
-        Regexp.last_match(1) ? parse_expression(Regexp.last_match(1)) : nil
+        next unless Regexp.last_match(1)
+
+        # Expression Parser returns cached objects, and we need to dup them to
+        # start the cycle over for each new cycle call.
+        # Liquid-C does not have a cache, so we don't need to dup the object.
+        var = parse_expression(Regexp.last_match(1))
+        var.is_a?(VariableLookup) ? var.dup : var
       end.compact
     end
 
@@ -71,6 +84,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_tag('cycle', Cycle)
 end

lib/liquid/tags/decrement.rb

@@ -1,38 +1,38 @@
 # frozen_string_literal: true
 
 module Liquid
-  # decrement is used in a place where one needs to insert a counter
-  #     into a template, and needs the counter to survive across
-  #     multiple instantiations of the template.
-  #     NOTE: decrement is a pre-decrement, --i,
-  #           while increment is post:      i++.
-  #
-  #     (To achieve the survival, the application must keep the context)
-  #
-  #     if the variable does not exist, it is created with value 0.
-
-  #   Hello: {% decrement variable %}
-  #
-  # gives you:
-  #
-  #    Hello: -1
-  #    Hello: -2
-  #    Hello: -3
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category variable
+  # @liquid_name decrement
+  # @liquid_summary
+  #   Creates a new variable, with a default value of -1, that's decreased by 1 with each subsequent call.
+  # @liquid_description
+  #   Variables that are declared with `decrement` are unique to the [layout](/themes/architecture/layouts), [template](/themes/architecture/templates),
+  #   or [section](/themes/architecture/sections) file that they're created in. However, the variable is shared across
+  #   [snippets](/themes/architecture#snippets) included in the file.
   #
+  #   Similarly, variables that are created with `decrement` are independent from those created with [`assign`](/docs/api/liquid/tags/assign)
+  #   and [`capture`](/docs/api/liquid/tags/capture). However, `decrement` and [`increment`](/docs/api/liquid/tags/increment) share
+  #   variables.
+  # @liquid_syntax
+  #   {% decrement variable_name %}
+  # @liquid_syntax_keyword variable_name The name of the variable being decremented.
   class Decrement < Tag
+    attr_reader :variable_name
+
     def initialize(tag_name, markup, options)
       super
-      @variable = markup.strip
+      @variable_name = markup.strip
     end
 
     def render_to_output_buffer(context, output)
-      value = context.environments.first[@variable] ||= 0
+      counter_environment = context.environments.first
+      value = counter_environment[@variable_name] || 0
       value -= 1
-      context.environments.first[@variable] = value
+      counter_environment[@variable_name] = value
       output << value.to_s
       output
     end
   end
-
-  Template.register_tag('decrement', Decrement)
 end

lib/liquid/tags/echo.rb

@@ -1,17 +1,26 @@
 # frozen_string_literal: true
 
 module Liquid
-  # Echo outputs an expression
-  #
-  #   {% echo monkey %}
-  #   {% echo user.name %}
-  #
-  # This is identical to variable output syntax, like {{ foo }}, but works
-  # inside {% liquid %} tags. The full syntax is supported, including filters:
-  #
-  #   {% echo user | link %}
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category syntax
+  # @liquid_name echo
+  # @liquid_summary
+  #   Outputs an expression.
+  # @liquid_description
+  #   Using the `echo` tag is the same as wrapping an expression in curly brackets (`{{` and `}}`). However, unlike the curly
+  #   bracket method, you can use the `echo` tag inside [`liquid` tags](/docs/api/liquid/tags/liquid).
   #
+  #   > Tip:
+  #   > You can use [filters](/docs/api/liquid/filters) on expressions inside `echo` tags.
+  # @liquid_syntax
+  #   {% liquid
+  #     echo expression
+  #   %}
+  # @liquid_syntax_keyword expression The expression to be output.
   class Echo < Tag
+    attr_reader :variable
+
     def initialize(tag_name, markup, parse_context)
       super
       @variable = Variable.new(markup, parse_context)
@@ -20,7 +29,11 @@ module Liquid
     def render(context)
       @variable.render_to_output_buffer(context, +'')
     end
-  end
 
-  Template.register_tag('echo', Echo)
+    class ParseTreeVisitor < Liquid::ParseTreeVisitor
+      def children
+        [@node.variable]
+      end
+    end
+  end
 end

lib/liquid/tags/for.rb

@@ -1,50 +1,29 @@
 # frozen_string_literal: true
 
 module Liquid
-  # "For" iterates over an array or collection.
-  # Several useful variables are available to you within the loop.
-  #
-  # == Basic usage:
-  #    {% for item in collection %}
-  #      {{ forloop.index }}: {{ item.name }}
-  #    {% endfor %}
-  #
-  # == Advanced usage:
-  #    {% for item in collection %}
-  #      <div {% if forloop.first %}class="first"{% endif %}>
-  #        Item {{ forloop.index }}: {{ item.name }}
-  #      </div>
-  #    {% else %}
-  #      There is nothing in the collection.
-  #    {% endfor %}
-  #
-  # You can also define a limit and offset much like SQL.  Remember
-  # that offset starts at 0 for the first item.
-  #
-  #    {% for item in collection limit:5 offset:10 %}
-  #      {{ item.name }}
-  #    {% end %}
-  #
-  #  To reverse the for loop simply use {% for item in collection reversed %} (note that the flag's spelling is different to the filter `reverse`)
-  #
-  # == Available variables:
-  #
-  # forloop.name:: 'item-collection'
-  # forloop.length:: Length of the loop
-  # forloop.index:: The current item's position in the collection;
-  #                 forloop.index starts at 1.
-  #                 This is helpful for non-programmers who start believe
-  #                 the first item in an array is 1, not 0.
-  # forloop.index0:: The current item's position in the collection
-  #                  where the first item is 0
-  # forloop.rindex:: Number of items remaining in the loop
-  #                  (length - index) where 1 is the last item.
-  # forloop.rindex0:: Number of items remaining in the loop
-  #                   where 0 is the last item.
-  # forloop.first:: Returns true if the item is the first item.
-  # forloop.last:: Returns true if the item is the last item.
-  # forloop.parentloop:: Provides access to the parent loop, if present.
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category iteration
+  # @liquid_name for
+  # @liquid_summary
+  #   Renders an expression for every item in an array.
+  # @liquid_description
+  #   You can do a maximum of 50 iterations with a `for` loop. If you need to iterate over more than 50 items, then use the
+  #   [`paginate` tag](/docs/api/liquid/tags/paginate) to split the items over multiple pages.
   #
+  #   > Tip:
+  #   > Every `for` loop has an associated [`forloop` object](/docs/api/liquid/objects/forloop) with information about the loop.
+  # @liquid_syntax
+  #   {% for variable in array %}
+  #     expression
+  #   {% endfor %}
+  # @liquid_syntax_keyword variable The current item in the array.
+  # @liquid_syntax_keyword array The array to iterate over.
+  # @liquid_syntax_keyword expression The expression to render for each iteration.
+  # @liquid_optional_param limit [number] The number of iterations to perform.
+  # @liquid_optional_param offset [number] The 1-based index to start iterating at.
+  # @liquid_optional_param range [untyped] A custom numeric range to iterate over.
+  # @liquid_optional_param reversed [untyped] Iterate in reverse order.
   class For < Block
     Syntax = /\A(#{VariableSegment}+)\s+in\s+(#{QuotedFragment}+)\s*(reversed)?/o
 
@@ -109,7 +88,7 @@ module Liquid
     end
 
     def strict_parse(markup)
-      p = Parser.new(markup)
+      p = @parse_context.new_parser(markup)
       @variable_name = p.consume(:id)
       raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_in") unless p.id?('in')
 
@@ -119,11 +98,12 @@ module Liquid
       @name     = "#{@variable_name}-#{collection_name}"
       @reversed = p.id?('reversed')
 
-      while p.look(:id) && p.look(:colon, 1)
+      while p.look(:comma) || p.look(:id)
+        p.consume?(:comma)
         unless (attribute = p.id?('limit') || p.id?('offset'))
           raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_attribute")
         end
-        p.consume
+        p.consume(:colon)
         set_attribute(attribute, p.expression)
       end
       p.consume(:end_of_string)
@@ -198,7 +178,6 @@ module Liquid
       case key
       when 'offset'
         @from = if expr == 'continue'
-          Usage.increment('for_offset_continue')
           :continue
         else
           parse_expression(expr)
@@ -222,6 +201,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_tag('for', For)
 end

lib/liquid/tags/if.rb

@@ -1,16 +1,18 @@
 # frozen_string_literal: true
 
 module Liquid
-  # If is the conditional block
-  #
-  #   {% if user.admin %}
-  #     Admin user!
-  #   {% else %}
-  #     Not admin user
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category conditional
+  # @liquid_name if
+  # @liquid_summary
+  #   Renders an expression if a specific condition is `true`.
+  # @liquid_syntax
+  #   {% if condition %}
+  #     expression
   #   {% endif %}
-  #
-  #    There are {% if count < 5 %} less {% else %} more {% endif %} items than you need.
-  #
+  # @liquid_syntax_keyword condition The condition to evaluate.
+  # @liquid_syntax_keyword expression The expression to render if the condition is met.
   class If < Block
     Syntax                  = /(#{QuotedFragment})\s*([=!<>a-z_]+)?\s*(#{QuotedFragment})?/o
     ExpressionsAndOperators = /(?:\b(?:\s?and\s?|\s?or\s?)\b|(?:\s*(?!\b(?:\s?and\s?|\s?or\s?)\b)(?:#{QuotedFragment}|\S+)\s*)+)/o
@@ -50,7 +52,11 @@ module Liquid
 
     def render_to_output_buffer(context, output)
       @blocks.each do |block|
-        if block.evaluate(context)
+        result = Liquid::Utils.to_liquid_value(
+          block.evaluate(context),
+        )
+
+        if result
           return block.attachment.render_to_output_buffer(context, output)
         end
       end
@@ -96,7 +102,7 @@ module Liquid
     end
 
     def strict_parse(markup)
-      p = Parser.new(markup)
+      p = @parse_context.new_parser(markup)
       condition = parse_binary_comparisons(p)
       p.consume(:end_of_string)
       condition
@@ -105,7 +111,7 @@ module Liquid
     def parse_binary_comparisons(p)
       condition = parse_comparison(p)
       first_condition = condition
-      while (op = (p.id?('and') || p.id?('or')))
+      while (op = p.id?('and') || p.id?('or'))
         child_condition = parse_comparison(p)
         condition.send(op, child_condition)
         condition = child_condition
@@ -129,6 +135,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_tag('if', If)
 end

lib/liquid/tags/ifchanged.rb

@@ -14,6 +14,4 @@ module Liquid
       output
     end
   end
-
-  Template.register_tag('ifchanged', Ifchanged)
 end

lib/liquid/tags/include.rb

@@ -1,20 +1,22 @@
 # frozen_string_literal: true
 
 module Liquid
-  # Include allows templates to relate with other templates
-  #
-  # Simply include another template:
-  #
-  #   {% include 'product' %}
-  #
-  # Include a template with a local variable:
-  #
-  #   {% include 'product' with products[0] %}
-  #
-  # Include a template for a collection:
-  #
-  #   {% include 'product' for products %}
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category theme
+  # @liquid_name include
+  # @liquid_summary
+  #   Renders a [snippet](/themes/architecture#snippets).
+  # @liquid_description
+  #   Inside the snippet, you can access and alter variables that are [created](/docs/api/liquid/tags/variable-tags) outside of the
+  #   snippet.
+  # @liquid_syntax
+  #   {% include 'filename' %}
+  # @liquid_syntax_keyword filename The name of the snippet to render, without the `.liquid` extension.
+  # @liquid_deprecated
+  #   Deprecated because the way that variables are handled reduces performance and makes code harder to both read and maintain.
   #
+  #   The `include` tag has been replaced by [`render`](/docs/api/liquid/tags/render).
   class Include < Tag
     prepend Tag::Disableable
 
@@ -50,12 +52,12 @@ module Liquid
 
     def render_to_output_buffer(context, output)
       template_name = context.evaluate(@template_name_expr)
-      raise ArgumentError, options[:locale].t("errors.argument.include") unless template_name
+      raise ArgumentError, options[:locale].t("errors.argument.include") unless template_name.is_a?(String)
 
       partial = PartialCache.load(
         template_name,
         context: context,
-        parse_context: parse_context
+        parse_context: parse_context,
       )
 
       context_variable_name = @alias_name || template_name.split('/').last
@@ -68,9 +70,11 @@ module Liquid
 
       old_template_name = context.template_name
       old_partial       = context.partial
+
       begin
-        context.template_name = template_name
-        context.partial       = true
+        context.template_name = partial.name
+        context.partial = true
+
         context.stack do
           @attributes.each do |key, value|
             context[key] = context.evaluate(value)
@@ -106,6 +110,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_tag('include', Include)
 end

lib/liquid/tags/increment.rb

@@ -1,35 +1,38 @@
 # frozen_string_literal: true
 
 module Liquid
-  # increment is used in a place where one needs to insert a counter
-  #     into a template, and needs the counter to survive across
-  #     multiple instantiations of the template.
-  #     (To achieve the survival, the application must keep the context)
-  #
-  #     if the variable does not exist, it is created with value 0.
-  #
-  #   Hello: {% increment variable %}
-  #
-  # gives you:
-  #
-  #    Hello: 0
-  #    Hello: 1
-  #    Hello: 2
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category variable
+  # @liquid_name increment
+  # @liquid_summary
+  #   Creates a new variable, with a default value of 0, that's increased by 1 with each subsequent call.
+  # @liquid_description
+  #   Variables that are declared with `increment` are unique to the [layout](/themes/architecture/layouts), [template](/themes/architecture/templates),
+  #   or [section](/themes/architecture/sections) file that they're created in. However, the variable is shared across
+  #   [snippets](/themes/architecture#snippets) included in the file.
   #
+  #   Similarly, variables that are created with `increment` are independent from those created with [`assign`](/docs/api/liquid/tags/assign)
+  #   and [`capture`](/docs/api/liquid/tags/capture). However, `increment` and [`decrement`](/docs/api/liquid/tags/decrement) share
+  #   variables.
+  # @liquid_syntax
+  #   {% increment variable_name %}
+  # @liquid_syntax_keyword variable_name The name of the variable being incremented.
   class Increment < Tag
+    attr_reader :variable_name
+
     def initialize(tag_name, markup, options)
       super
-      @variable = markup.strip
+      @variable_name = markup.strip
     end
 
     def render_to_output_buffer(context, output)
-      value = context.environments.first[@variable] ||= 0
-      context.environments.first[@variable] = value + 1
+      counter_environment = context.environments.first
+      value = counter_environment[@variable_name] || 0
+      counter_environment[@variable_name] = value + 1
 
       output << value.to_s
       output
     end
   end
-
-  Template.register_tag('increment', Increment)
 end

lib/liquid/tags/inline_comment.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+module Liquid
+  class InlineComment < Tag
+    def initialize(tag_name, markup, options)
+      super
+
+      # Semantically, a comment should only ignore everything after it on the line.
+      # Currently, this implementation doesn't support mixing a comment with another tag
+      # but we need to reserve future support for this and prevent the introduction
+      # of inline comments from being backward incompatible change.
+      #
+      # As such, we're forcing users to put a # symbol on every line otherwise this
+      # tag will throw an error.
+      if markup.match?(/\n\s*[^#\s]/)
+        raise SyntaxError, options[:locale].t("errors.syntax.inline_comment_invalid")
+      end
+    end
+
+    def render_to_output_buffer(_context, output)
+      output
+    end
+
+    def blank?
+      true
+    end
+  end
+end

lib/liquid/tags/raw.rb

@@ -1,9 +1,19 @@
 # frozen_string_literal: true
 
 module Liquid
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category syntax
+  # @liquid_name raw
+  # @liquid_summary
+  #   Outputs any Liquid code as text instead of rendering it.
+  # @liquid_syntax
+  #   {% raw %}
+  #     expression
+  #   {% endraw %}
+  # @liquid_syntax_keyword expression The expression to be output without being rendered.
   class Raw < Block
     Syntax = /\A\s*\z/
-    FullTokenPossiblyInvalid = /\A(.*)#{TagStart}\s*(\w+)\s*(.*)?#{TagEnd}\z/om
 
     def initialize(tag_name, markup, parse_context)
       super
@@ -14,7 +24,8 @@ module Liquid
     def parse(tokens)
       @body = +''
       while (token = tokens.shift)
-        if token =~ FullTokenPossiblyInvalid && block_delimiter == Regexp.last_match(2)
+        if token =~ BlockBody::FullTokenPossiblyInvalid && block_delimiter == Regexp.last_match(2)
+          parse_context.trim_whitespace = (token[-3] == WhitespaceControl)
           @body << Regexp.last_match(1) if Regexp.last_match(1) != ""
           return
         end
@@ -45,6 +56,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_tag('raw', Raw)
 end

lib/liquid/tags/render.rb

@@ -1,13 +1,37 @@
 # frozen_string_literal: true
 
 module Liquid
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category theme
+  # @liquid_name render
+  # @liquid_summary
+  #   Renders a [snippet](/themes/architecture#snippets) or [app block](/themes/architecture/sections/section-schema#render-app-blocks).
+  # @liquid_description
+  #   Inside snippets and app blocks, you can't directly access variables that are [created](/docs/api/liquid/tags/variable-tags) outside
+  #   of the snippet or app block. However, you can [specify variables as parameters](/docs/api/liquid/tags/render#render-passing-variables-to-a-snippet)
+  #   to pass outside variables to snippets.
+  #
+  #   While you can't directly access created variables, you can access global objects, as well as any objects that are
+  #   directly accessible outside the snippet or app block. For example, a snippet or app block inside the [product template](/themes/architecture/templates/product)
+  #   can access the [`product` object](/docs/api/liquid/objects/product), and a snippet or app block inside a [section](/themes/architecture/sections)
+  #   can access the [`section` object](/docs/api/liquid/objects/section).
+  #
+  #   Outside a snippet or app block, you can't access variables created inside the snippet or app block.
+  #
+  #   > Note:
+  #   > When you render a snippet using the `render` tag, you can't use the [`include` tag](/docs/api/liquid/tags/include)
+  #   > inside the snippet.
+  # @liquid_syntax
+  #   {% render 'filename' %}
+  # @liquid_syntax_keyword filename The name of the snippet to render, without the `.liquid` extension.
   class Render < Tag
     FOR = 'for'
     SYNTAX = /(#{QuotedString}+)(\s+(with|#{FOR})\s+(#{QuotedFragment}+))?(\s+(?:as)\s+(#{VariableSegment}+))?/o
 
     disable_tags "include"
 
-    attr_reader :template_name_expr, :attributes
+    attr_reader :template_name_expr, :variable_name_expr, :attributes, :alias_name
 
     def initialize(tag_name, markup, options)
       super
@@ -21,7 +45,7 @@ module Liquid
       @alias_name = Regexp.last_match(6)
       @variable_name_expr = variable_name ? parse_expression(variable_name) : nil
       @template_name_expr = parse_expression(template_name)
-      @for = (with_or_for == FOR)
+      @is_for_loop = (with_or_for == FOR)
 
       @attributes = {}
       markup.scan(TagAttributes) do |key, value|
@@ -29,26 +53,30 @@ module Liquid
       end
     end
 
+    def for_loop?
+      @is_for_loop
+    end
+
     def render_to_output_buffer(context, output)
       render_tag(context, output)
     end
 
     def render_tag(context, output)
-      # Though we evaluate this here we will only ever parse it as a string literal.
-      template_name = context.evaluate(@template_name_expr)
-      raise ArgumentError, options[:locale].t("errors.argument.include") unless template_name
+      # The expression should be a String literal, which parses to a String object
+      template_name = @template_name_expr
+      raise ::ArgumentError unless template_name.is_a?(String)
 
       partial = PartialCache.load(
         template_name,
         context: context,
-        parse_context: parse_context
+        parse_context: parse_context,
       )
 
       context_variable_name = @alias_name || template_name.split('/').last
 
       render_partial_func = ->(var, forloop) {
         inner_context               = context.new_isolated_subcontext
-        inner_context.template_name = template_name
+        inner_context.template_name = partial.name
         inner_context.partial       = true
         inner_context['forloop']    = forloop if forloop
 
@@ -61,7 +89,7 @@ module Liquid
       }
 
       variable = @variable_name_expr ? context.evaluate(@variable_name_expr) : nil
-      if @for && variable.respond_to?(:each) && variable.respond_to?(:count)
+      if @is_for_loop && variable.respond_to?(:each) && variable.respond_to?(:count)
         forloop = Liquid::ForloopDrop.new(template_name, variable.count, nil)
         variable.each { |var| render_partial_func.call(var, forloop) }
       else
@@ -75,10 +103,9 @@ module Liquid
       def children
         [
           @node.template_name_expr,
+          @node.variable_name_expr,
         ] + @node.attributes.values
       end
     end
   end
-
-  Template.register_tag('render', Render)
 end

lib/liquid/tags/table_row.rb

@@ -1,6 +1,28 @@
 # frozen_string_literal: true
 
 module Liquid
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category iteration
+  # @liquid_name tablerow
+  # @liquid_summary
+  #   Generates HTML table rows for every item in an array.
+  # @liquid_description
+  #   The `tablerow` tag must be wrapped in HTML `<table>` and `</table>` tags.
+  #
+  #   > Tip:
+  #   > Every `tablerow` loop has an associated [`tablerowloop` object](/docs/api/liquid/objects/tablerowloop) with information about the loop.
+  # @liquid_syntax
+  #   {% tablerow variable in array %}
+  #     expression
+  #   {% endtablerow %}
+  # @liquid_syntax_keyword variable The current item in the array.
+  # @liquid_syntax_keyword array The array to iterate over.
+  # @liquid_syntax_keyword expression The expression to render.
+  # @liquid_optional_param cols [number] The number of columns that the table should have.
+  # @liquid_optional_param limit [number] The number of iterations to perform.
+  # @liquid_optional_param offset [number] The 1-based index to start iterating at.
+  # @liquid_optional_param range [untyped] A custom numeric range to iterate over.
   class TableRow < Block
     Syntax = /(\w+)\s+in\s+(#{QuotedFragment}+)/o
 
@@ -23,13 +45,13 @@ module Liquid
     def render_to_output_buffer(context, output)
       (collection = context.evaluate(@collection_name)) || (return '')
 
-      from = @attributes.key?('offset') ? context.evaluate(@attributes['offset']).to_i : 0
-      to   = @attributes.key?('limit')  ? from + context.evaluate(@attributes['limit']).to_i : nil
+      from = @attributes.key?('offset') ? to_integer(context.evaluate(@attributes['offset'])) : 0
+      to = @attributes.key?('limit') ? from + to_integer(context.evaluate(@attributes['limit'])) : nil
 
       collection = Utils.slice_collection(collection, from, to)
       length     = collection.length
 
-      cols = context.evaluate(@attributes['cols']).to_i
+      cols = @attributes.key?('cols') ? to_integer(context.evaluate(@attributes['cols'])) : length
 
       output << "<tr class=\"row1\">\n"
       context.stack do
@@ -43,6 +65,12 @@ module Liquid
           super
           output << '</td>'
 
+          # Handle any interrupts if they exist.
+          if context.interrupt?
+            interrupt = context.pop_interrupt
+            break if interrupt.is_a?(BreakInterrupt)
+          end
+
           if tablerowloop.col_last && !tablerowloop.last
             output << "</tr>\n<tr class=\"row#{tablerowloop.row + 1}\">"
           end
@@ -60,7 +88,13 @@ module Liquid
         super + @node.attributes.values + [@node.collection_name]
       end
     end
-  end
 
-  Template.register_tag('tablerow', TableRow)
+    private
+
+    def to_integer(value)
+      value.to_i
+    rescue NoMethodError
+      raise Liquid::ArgumentError, "invalid integer"
+    end
+  end
 end

lib/liquid/tags/unless.rb

@@ -3,21 +3,40 @@
 require_relative 'if'
 
 module Liquid
-  # Unless is a conditional just like 'if' but works on the inverse logic.
-  #
-  #   {% unless x < 0 %} x is greater than zero {% endunless %}
-  #
+  # @liquid_public_docs
+  # @liquid_type tag
+  # @liquid_category conditional
+  # @liquid_name unless
+  # @liquid_summary
+  #   Renders an expression unless a specific condition is `true`.
+  # @liquid_description
+  #   > Tip:
+  #   > Similar to the [`if` tag](/docs/api/liquid/tags/if), you can use `elsif` to add more conditions to an `unless` tag.
+  # @liquid_syntax
+  #   {% unless condition %}
+  #     expression
+  #   {% endunless %}
+  # @liquid_syntax_keyword condition The condition to evaluate.
+  # @liquid_syntax_keyword expression The expression to render unless the condition is met.
   class Unless < If
     def render_to_output_buffer(context, output)
       # First condition is interpreted backwards ( if not )
       first_block = @blocks.first
-      unless first_block.evaluate(context)
+      result = Liquid::Utils.to_liquid_value(
+        first_block.evaluate(context),
+      )
+
+      unless result
         return first_block.attachment.render_to_output_buffer(context, output)
       end
 
       # After the first condition unless works just like if
       @blocks[1..-1].each do |block|
-        if block.evaluate(context)
+        result = Liquid::Utils.to_liquid_value(
+          block.evaluate(context),
+        )
+
+        if result
           return block.attachment.render_to_output_buffer(context, output)
         end
       end
@@ -25,6 +44,4 @@ module Liquid
       output
     end
   end
-
-  Template.register_tag('unless', Unless)
 end

lib/liquid/template.rb

@@ -15,45 +15,9 @@ module Liquid
   #   template.render('user_name' => 'bob')
   #
   class Template
-    attr_accessor :root
+    attr_accessor :root, :name
     attr_reader :resource_limits, :warnings
 
-    class TagRegistry
-      include Enumerable
-
-      def initialize
-        @tags  = {}
-        @cache = {}
-      end
-
-      def [](tag_name)
-        return nil unless @tags.key?(tag_name)
-        return @cache[tag_name] if Liquid.cache_classes
-
-        lookup_class(@tags[tag_name]).tap { |o| @cache[tag_name] = o }
-      end
-
-      def []=(tag_name, klass)
-        @tags[tag_name]  = klass.name
-        @cache[tag_name] = klass
-      end
-
-      def delete(tag_name)
-        @tags.delete(tag_name)
-        @cache.delete(tag_name)
-      end
-
-      def each(&block)
-        @tags.each(&block)
-      end
-
-      private
-
-      def lookup_class(name)
-        Object.const_get(name)
-      end
-    end
-
     attr_reader :profiler
 
     class << self
@@ -61,52 +25,83 @@ module Liquid
       # :lax acts like liquid 2.5 and silently ignores malformed tags in most cases.
       # :warn is the default and will give deprecation warnings when invalid syntax is used.
       # :strict will enforce correct syntax.
-      attr_accessor :error_mode
-      Template.error_mode = :lax
-
-      attr_accessor :default_exception_renderer
-      Template.default_exception_renderer = lambda do |exception|
-        exception
+      def error_mode=(mode)
+        Deprecations.warn("Template.error_mode=", "Environment#error_mode=")
+        Environment.default.error_mode = mode
       end
 
-      attr_accessor :file_system
-      Template.file_system = BlankFileSystem.new
+      def error_mode
+        Environment.default.error_mode
+      end
 
-      attr_accessor :tags
-      Template.tags = TagRegistry.new
-      private :tags=
+      def default_exception_renderer=(renderer)
+        Deprecations.warn("Template.default_exception_renderer=", "Environment#exception_renderer=")
+        Environment.default.exception_renderer = renderer
+      end
+
+      def default_exception_renderer
+        Environment.default.exception_renderer
+      end
+
+      def file_system=(file_system)
+        Deprecations.warn("Template.file_system=", "Environment#file_system=")
+        Environment.default.file_system = file_system
+      end
+
+      def file_system
+        Environment.default.file_system
+      end
+
+      def tags
+        Environment.default.tags
+      end
 
       def register_tag(name, klass)
-        tags[name.to_s] = klass
+        Deprecations.warn("Template.register_tag", "Environment#register_tag")
+        Environment.default.register_tag(name, klass)
       end
 
       # Pass a module with filter methods which should be available
       # to all liquid views. Good for registering the standard library
       def register_filter(mod)
-        StrainerFactory.add_global_filter(mod)
+        Deprecations.warn("Template.register_filter", "Environment#register_filter")
+        Environment.default.register_filter(mod)
       end
 
-      attr_accessor :default_resource_limits
-      Template.default_resource_limits = {}
-      private :default_resource_limits=
+      private def default_resource_limits=(limits)
+        Deprecations.warn("Template.default_resource_limits=", "Environment#default_resource_limits=")
+        Environment.default.default_resource_limits = limits
+      end
+
+      def default_resource_limits
+        Environment.default.default_resource_limits
+      end
 
       # creates a new <tt>Template</tt> object from liquid source code
       # To enable profiling, pass in <tt>profile: true</tt> as an option.
       # See Liquid::Profiler for more information
       def parse(source, options = {})
-        new.parse(source, options)
+        environment = options[:environment] || Environment.default
+        new(environment: environment).parse(source, options)
       end
     end
 
-    def initialize
+    def initialize(environment: Environment.default)
+      @environment = environment
       @rethrow_errors  = false
-      @resource_limits = ResourceLimits.new(Template.default_resource_limits)
+      @resource_limits = ResourceLimits.new(environment.default_resource_limits)
     end
 
     # Parse source code.
     # Returns self for easy chaining
     def parse(source, options = {})
       parse_context = configure_options(options)
+      source = source.to_s.to_str
+
+      unless source.valid_encoding?
+        raise TemplateEncodingError, parse_context.locale.t("errors.syntax.invalid_template_encoding")
+      end
+
       tokenizer     = parse_context.new_tokenizer(source, start_line_number: @line_numbers && 1)
       @root         = Document.parse(tokenizer, parse_context)
       self
@@ -156,26 +151,25 @@ module Liquid
         c
       when Liquid::Drop
         drop         = args.shift
-        drop.context = Context.new([drop, assigns], instance_assigns, registers, @rethrow_errors, @resource_limits)
+        drop.context = Context.new([drop, assigns], instance_assigns, registers, @rethrow_errors, @resource_limits, {}, @environment)
       when Hash
-        Context.new([args.shift, assigns], instance_assigns, registers, @rethrow_errors, @resource_limits)
+        Context.new([args.shift, assigns], instance_assigns, registers, @rethrow_errors, @resource_limits, {}, @environment)
       when nil
-        Context.new(assigns, instance_assigns, registers, @rethrow_errors, @resource_limits)
+        Context.new(assigns, instance_assigns, registers, @rethrow_errors, @resource_limits, {}, @environment)
       else
         raise ArgumentError, "Expected Hash or Liquid::Context as parameter"
       end
 
       output = nil
 
-      context_register = context.registers.is_a?(StaticRegisters) ? context.registers.static : context.registers
-
       case args.last
       when Hash
         options = args.pop
         output  = options[:output] if options[:output]
+        static_registers = context.registers.static
 
         options[:registers]&.each do |key, register|
-          context_register[key] = register
+          static_registers[key] = register
         end
 
         apply_options_to_context(context, options)
@@ -190,6 +184,8 @@ module Liquid
         @profiler = context.profiler = Liquid::Profiler.new
       end
 
+      context.template_name ||= name
+
       begin
         # render the nodelist.
         @root.render_to_output_buffer(context, output || +'')
@@ -219,8 +215,14 @@ module Liquid
       @options      = options
       @profiling    = profiling
       @line_numbers = options[:line_numbers] || @profiling
-      parse_context = options.is_a?(ParseContext) ? options : ParseContext.new(options)
-      @warnings     = parse_context.warnings
+      parse_context = if options.is_a?(ParseContext)
+        options
+      else
+        opts = options.key?(:environment) ? options : options.merge(environment: @environment)
+        ParseContext.new(opts)
+      end
+
+      @warnings = parse_context.warnings
       parse_context
     end
 

lib/liquid/tokenizer.rb

@@ -1,18 +1,45 @@
 # frozen_string_literal: true
 
+require "strscan"
+
 module Liquid
   class Tokenizer
     attr_reader :line_number, :for_liquid_tag
 
-    def initialize(source, line_numbers = false, line_number: nil, for_liquid_tag: false)
-      @source         = source
-      @line_number    = line_number || (line_numbers ? 1 : nil)
+    TAG_END = /%\}/
+    TAG_OR_VARIABLE_START = /\{[\{\%]/
+    NEWLINE = /\n/
+
+    OPEN_CURLEY = "{".ord
+    CLOSE_CURLEY = "}".ord
+    PERCENTAGE = "%".ord
+
+    def initialize(
+      source:,
+      string_scanner:,
+      line_numbers: false,
+      line_number: nil,
+      for_liquid_tag: false
+    )
+      @line_number = line_number || (line_numbers ? 1 : nil)
       @for_liquid_tag = for_liquid_tag
-      @tokens         = tokenize
+      @source = source.to_s.to_str
+      @offset = 0
+      @tokens = []
+
+      if @source
+        @ss = string_scanner
+        @ss.string = @source
+        tokenize
+      end
     end
 
     def shift
-      (token = @tokens.shift) || return
+      token = @tokens[@offset]
+
+      return unless token
+
+      @offset += 1
 
       if @line_number
         @line_number += @for_liquid_tag ? 1 : token.count("\n")
@@ -24,16 +51,105 @@ module Liquid
     private
 
     def tokenize
-      return [] if @source.to_s.empty?
+      if @for_liquid_tag
+        @tokens = @source.split("\n")
+      else
+        @tokens << shift_normal until @ss.eos?
+      end
 
-      return @source.split("\n") if @for_liquid_tag
+      @source = nil
+      @ss = nil
+    end
 
-      tokens = @source.split(TemplateParser)
+    def shift_normal
+      token = next_token
 
-      # removes the rogue empty element at the beginning of the array
-      tokens.shift if tokens[0]&.empty?
+      return unless token
 
-      tokens
+      token
+    end
+
+    def next_token
+      # possible states: :text, :tag, :variable
+      byte_a = @ss.peek_byte
+
+      if byte_a == OPEN_CURLEY
+        @ss.scan_byte
+
+        byte_b = @ss.peek_byte
+
+        if byte_b == PERCENTAGE
+          @ss.scan_byte
+          return next_tag_token
+        elsif byte_b == OPEN_CURLEY
+          @ss.scan_byte
+          return next_variable_token
+        end
+
+        @ss.pos -= 1
+      end
+
+      next_text_token
+    end
+
+    def next_text_token
+      start = @ss.pos
+
+      unless @ss.skip_until(TAG_OR_VARIABLE_START)
+        token = @ss.rest
+        @ss.terminate
+        return token
+      end
+
+      pos = @ss.pos -= 2
+      @source.byteslice(start, pos - start)
+    end
+
+    def next_variable_token
+      start = @ss.pos - 2
+
+      byte_a = byte_b = @ss.scan_byte
+
+      while byte_b
+        byte_a = @ss.scan_byte while byte_a && (byte_a != CLOSE_CURLEY && byte_a != OPEN_CURLEY)
+
+        break unless byte_a
+
+        if @ss.eos?
+          return byte_a == CLOSE_CURLEY ? @source.byteslice(start, @ss.pos - start) : "{{"
+        end
+
+        byte_b = @ss.scan_byte
+
+        if byte_a == CLOSE_CURLEY
+          if byte_b == CLOSE_CURLEY
+            return @source.byteslice(start, @ss.pos - start)
+          elsif byte_b != CLOSE_CURLEY
+            @ss.pos -= 1
+            return @source.byteslice(start, @ss.pos - start)
+          end
+        elsif byte_a == OPEN_CURLEY && byte_b == PERCENTAGE
+          return next_tag_token_with_start(start)
+        end
+
+        byte_a = byte_b
+      end
+
+      "{{"
+    end
+
+    def next_tag_token
+      start = @ss.pos - 2
+      if (len = @ss.skip_until(TAG_END))
+        @source.byteslice(start, len + 2)
+      else
+        "{%"
+      end
+    end
+
+    def next_tag_token_with_start(start)
+      @ss.skip_until(TAG_END)
+      @source.byteslice(start, @ss.pos - start)
     end
   end
 end

lib/liquid/utils.rb

@@ -81,5 +81,13 @@ module Liquid
     rescue ::ArgumentError
       nil
     end
+
+    def self.to_liquid_value(obj)
+      # Enable "obj" to represent itself as a primitive value like integer, string, or boolean
+      return obj.to_liquid_value if obj.respond_to?(:to_liquid_value)
+
+      # Otherwise return the object itself
+      obj
+    end
   end
 end

lib/liquid/variable.rb

@@ -47,7 +47,7 @@ module Liquid
 
       name_markup   = Regexp.last_match(1)
       filter_markup = Regexp.last_match(2)
-      @name         = Expression.parse(name_markup)
+      @name         = parse_context.parse_expression(name_markup)
       if filter_markup =~ FilterMarkupRegex
         filters = Regexp.last_match(1).scan(FilterParser)
         filters.each do |f|
@@ -61,14 +61,14 @@ module Liquid
 
     def strict_parse(markup)
       @filters = []
-      p = Parser.new(markup)
+      p = @parse_context.new_parser(markup)
 
       return if p.look(:end_of_string)
 
-      @name = Expression.parse(p.expression)
+      @name = parse_context.parse_expression(p.expression)
       while p.consume?(:pipe)
         filtername = p.consume(:id)
-        filterargs = p.consume?(:colon) ? parse_filterargs(p) : []
+        filterargs = p.consume?(:colon) ? parse_filterargs(p) : Const::EMPTY_ARRAY
         @filters << parse_filter_expressions(filtername, filterargs)
       end
       p.consume(:end_of_string)
@@ -95,15 +95,21 @@ module Liquid
 
     def render_to_output_buffer(context, output)
       obj = render(context)
+      render_obj_to_output(obj, output)
+      output
+    end
 
-      if obj.is_a?(Array)
-        output << obj.join
-      elsif obj.nil?
-      else
+    def render_obj_to_output(obj, output)
+      case obj
+      when NilClass
+        # Do nothing
+      when Array
+        obj.each do |o|
+          render_obj_to_output(o, output)
+        end
+      when
         output << obj.to_s
       end
-
-      output
     end
 
     def disabled?(_context)
@@ -122,9 +128,9 @@ module Liquid
       unparsed_args.each do |a|
         if (matches = a.match(JustTagAttributes))
           keyword_args           ||= {}
-          keyword_args[matches[1]] = Expression.parse(matches[2])
+          keyword_args[matches[1]] = parse_context.parse_expression(matches[2])
         else
-          filter_args << Expression.parse(a)
+          filter_args << parse_context.parse_expression(a)
         end
       end
       result = [filter_name, filter_args]

lib/liquid/variable_lookup.rb

@@ -2,21 +2,24 @@
 
 module Liquid
   class VariableLookup
-    SQUARE_BRACKETED = /\A\[(.*)\]\z/m
-    COMMAND_METHODS  = ['size', 'first', 'last'].freeze
+    COMMAND_METHODS = ['size', 'first', 'last'].freeze
 
     attr_reader :name, :lookups
 
-    def self.parse(markup)
-      new(markup)
+    def self.parse(markup, string_scanner = StringScanner.new(""), cache = nil)
+      new(markup, string_scanner, cache)
     end
 
-    def initialize(markup)
+    def initialize(markup, string_scanner = StringScanner.new(""), cache = nil)
       lookups = markup.scan(VariableParser)
 
       name = lookups.shift
-      if name =~ SQUARE_BRACKETED
-        name = Expression.parse(Regexp.last_match(1))
+      if name&.start_with?('[') && name&.end_with?(']')
+        name = Expression.parse(
+          name[1..-2],
+          string_scanner,
+          cache,
+        )
       end
       @name = name
 
@@ -25,14 +28,22 @@ module Liquid
 
       @lookups.each_index do |i|
         lookup = lookups[i]
-        if lookup =~ SQUARE_BRACKETED
-          lookups[i] = Expression.parse(Regexp.last_match(1))
+        if lookup&.start_with?('[') && lookup&.end_with?(']')
+          lookups[i] = Expression.parse(
+            lookup[1..-2],
+            string_scanner,
+            cache,
+          )
         elsif COMMAND_METHODS.include?(lookup)
           @command_flags |= 1 << i
         end
       end
     end
 
+    def lookup_command?(lookup_index)
+      @command_flags & (1 << lookup_index) != 0
+    end
+
     def evaluate(context)
       name   = context.evaluate(@name)
       object = context.find_variable(name)
@@ -40,6 +51,9 @@ module Liquid
       @lookups.each_index do |i|
         key = context.evaluate(@lookups[i])
 
+        # Cast "key" to its liquid value to enable it to act as a primitive value
+        key = Liquid::Utils.to_liquid_value(key)
+
         # If object is a hash- or array-like object we look for the
         # presence of the key and if its available we return it
         if object.respond_to?(:[]) &&
@@ -53,7 +67,7 @@ module Liquid
           # Some special cases. If the part wasn't in square brackets and
           # no key with the same name was found we interpret following calls
           # as commands and call them on the current object
-        elsif @command_flags & (1 << i) != 0 && object.respond_to?(key)
+        elsif lookup_command?(i) && object.respond_to?(key)
           object = object.send(key).to_liquid
 
           # No key was present with the desired value and it wasn't one of the directly supported

lib/liquid/version.rb

@@ -2,5 +2,5 @@
 # frozen_string_literal: true
 
 module Liquid
-  VERSION = "5.0.0"
+  VERSION = "5.6.4"
 end

liquid.gemspec

@@ -13,22 +13,24 @@ Gem::Specification.new do |s|
   s.summary     = "A secure, non-evaling end user template engine with aesthetic markup."
   s.authors     = ["Tobias Lütke"]
   s.email       = ["[email protected]"]
-  s.homepage    = "http://www.liquidmarkup.org"
+  s.homepage    = "https://shopify.github.io/liquid/"
   s.license     = "MIT"
   # s.description = "A secure, non-evaling end user template engine with aesthetic markup."
 
-  s.required_ruby_version     = ">= 2.5.0"
+  s.required_ruby_version     = ">= 3.0.0"
   s.required_rubygems_version = ">= 1.3.7"
 
   s.metadata['allowed_push_host'] = 'https://rubygems.org'
 
-  s.test_files  = Dir.glob("{test}/**/*")
-  s.files       = Dir.glob("{lib}/**/*") + %w(LICENSE README.md)
+  s.files = Dir.glob("{lib}/**/*") + %w(LICENSE README.md)
 
   s.extra_rdoc_files = ["History.md", "README.md"]
 
   s.require_path = "lib"
 
+  s.add_dependency("strscan", ">= 3.1.1")
+  s.add_dependency("bigdecimal")
+
   s.add_development_dependency('rake', '~> 13.0')
   s.add_development_dependency('minitest')
 end

performance/benchmark.rb

@@ -3,18 +3,23 @@
 require 'benchmark/ips'
 require_relative 'theme_runner'
 
-Liquid::Template.error_mode = ARGV.first.to_sym if ARGV.first
+RubyVM::YJIT.enable if defined?(RubyVM::YJIT)
+Liquid::Environment.default.error_mode = ARGV.first.to_sym if ARGV.first
+
 profiler = ThemeRunner.new
 
 Benchmark.ips do |x|
-  x.time   = 10
-  x.warmup = 5
+  x.time   = 20
+  x.warmup = 10
 
   puts
   puts "Running benchmark for #{x.time} seconds (with #{x.warmup} seconds warmup)."
   puts
 
-  x.report("parse:") { profiler.compile }
-  x.report("render:") { profiler.render }
-  x.report("parse & render:") { profiler.run }
+  phase = ENV["PHASE"] || "all"
+
+  x.report("tokenize:") { profiler.tokenize } if phase == "all" || phase == "tokenize"
+  x.report("parse:") { profiler.compile } if phase == "all" || phase == "parse"
+  x.report("render:") { profiler.render } if phase == "all" || phase == "render"
+  x.report("parse & render:") { profiler.run } if phase == "all" || phase == "run"
 end

performance/shopify/database.rb

@@ -3,11 +3,19 @@
 require 'yaml'
 
 module Database
+  DATABASE_FILE_PATH = "#{__dir__}/vision.database.yml"
+
   # Load the standard vision toolkit database and re-arrage it to be simply exportable
   # to liquid as assigns. All this is based on Shopify
   def self.tables
     @tables ||= begin
-      db = YAML.load_file("#{__dir__}/vision.database.yml")
+      db =
+        if YAML.respond_to?(:unsafe_load_file) # Only Psych 4+ can use unsafe_load_file
+          # unsafe_load_file is needed for YAML references
+          YAML.unsafe_load_file(DATABASE_FILE_PATH)
+        else
+          YAML.load_file(DATABASE_FILE_PATH)
+        end
 
       # From vision source
       db['products'].each do |product|
@@ -41,8 +49,3 @@ module Database
     end
   end
 end
-
-if __FILE__ == $PROGRAM_NAME
-  p(Database.tables['collections']['frontpage'].keys)
-  # p Database.tables['blog']['articles']
-end

performance/shopify/liquid.rb

@@ -11,11 +11,12 @@ require_relative 'shop_filter'
 require_relative 'tag_filter'
 require_relative 'weight_filter'
 
-Liquid::Template.register_tag('paginate', Paginate)
-Liquid::Template.register_tag('form', CommentForm)
+default_environment = Liquid::Environment.default
+default_environment.register_tag('paginate', Paginate)
+default_environment.register_tag('form', CommentForm)
 
-Liquid::Template.register_filter(JsonFilter)
-Liquid::Template.register_filter(MoneyFilter)
-Liquid::Template.register_filter(WeightFilter)
-Liquid::Template.register_filter(ShopFilter)
-Liquid::Template.register_filter(TagFilter)
+default_environment.register_filter(JsonFilter)
+default_environment.register_filter(MoneyFilter)
+default_environment.register_filter(WeightFilter)
+default_environment.register_filter(ShopFilter)
+default_environment.register_filter(TagFilter)

performance/shopify/paginate.rb

@@ -45,8 +45,8 @@ class Paginate < Liquid::Block
 
       pagination['items']      = collection_size
       pagination['pages']      = page_count - 1
-      pagination['previous']   = link('&laquo; Previous', current_page - 1)  unless 1 >= current_page
-      pagination['next']       = link('Next &raquo;', current_page + 1)      unless page_count <= current_page + 1
+      pagination['previous']   = link('&laquo; Previous', current_page - 1)  if 1 < current_page
+      pagination['next']       = link('Next &raquo;', current_page + 1)      if page_count > current_page + 1
       pagination['parts']      = []
 
       hellip_break = false

performance/theme_runner.rb

@@ -3,7 +3,7 @@
 # This profiler run simulates Shopify.
 # We are looking in the tests directory for liquid files and render them within the designated layout file.
 # We will also export a substantial database to liquid which the templates can render values of.
-# All this is to make the benchmark as non syntetic as possible. All templates and tests are lifted from
+# All this is to make the benchmark as non synthetic as possible. All templates and tests are lifted from
 # direct real-world usage and the profiler measures code that looks very similar to the way it looks in
 # Shopify which is likely the biggest user of liquid in the world which something to the tune of several
 # million Template#render calls a day.
@@ -48,6 +48,19 @@ class ThemeRunner
     end
   end
 
+  # `tokenize` will just test the tokenizen portion of liquid without any templates
+  def tokenize
+    ss = StringScanner.new("")
+    @tests.each do |test_hash|
+      tokenizer = Liquid::Tokenizer.new(
+        source: test_hash[:liquid],
+        string_scanner: ss,
+        line_numbers: true,
+      )
+      while tokenizer.shift; end
+    end
+  end
+
   # `run` is called to benchmark rendering and compiling at the same time
   def run
     each_test do |liquid, layout, assigns, page_template, template_name|

performance/unit/expression_benchmark.rb

@@ -0,0 +1,94 @@
+# frozen_string_literal: true
+
+require "benchmark/ips"
+
+# benchmark liquid lexing
+
+require 'liquid'
+
+RubyVM::YJIT.enable
+
+STRING_MARKUPS = [
+  "\"foo\"",
+  "\"fooooooooooo\"",
+  "\"foooooooooooooooooooooooooooooo\"",
+  "'foo'",
+  "'fooooooooooo'",
+  "'foooooooooooooooooooooooooooooo'",
+]
+
+VARIABLE_MARKUPS = [
+  "article",
+  "article.title",
+  "article.title.size",
+  "very_long_variable_name_2024_11_05",
+  "very_long_variable_name_2024_11_05.size",
+]
+
+NUMBER_MARKUPS = [
+  "0",
+  "35",
+  "1241891024912849",
+  "3.5",
+  "3.51214128409128",
+  "12381902839.123819283910283",
+  "123.456.789",
+  "-123",
+  "-12.33",
+  "-405.231",
+  "-0",
+  "0",
+  "0.0",
+  "0.0000000000000000000000",
+  "0.00000000001",
+]
+
+RANGE_MARKUPS = [
+  "(1..30)",
+  "(1...30)",
+  "(1..30..5)",
+  "(1.0...30.0)",
+  "(1.........30)",
+  "(1..foo)",
+  "(foo..30)",
+  "(foo..bar)",
+  "(foo...bar...100)",
+  "(foo...bar...100.0)",
+]
+
+LITERAL_MARKUPS = [
+  nil,
+  'nil',
+  'null',
+  '',
+  'true',
+  'false',
+  'blank',
+  'empty',
+]
+
+MARKUPS = {
+  "string" => STRING_MARKUPS,
+  "literal" => LITERAL_MARKUPS,
+  "variable" => VARIABLE_MARKUPS,
+  "number" => NUMBER_MARKUPS,
+  "range" => RANGE_MARKUPS,
+}
+
+Benchmark.ips do |x|
+  x.config(time: 5, warmup: 5)
+
+  MARKUPS.each do |type, markups|
+    x.report("Liquid::Expression#parse: #{type}") do
+      markups.each do |markup|
+        Liquid::Expression.parse(markup)
+      end
+    end
+  end
+
+  x.report("Liquid::Expression#parse: all") do
+    MARKUPS.values.flatten.each do |markup|
+      Liquid::Expression.parse(markup)
+    end
+  end
+end

performance/unit/lexer_benchmark.rb

@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+require "benchmark/ips"
+
+# benchmark liquid lexing
+
+require 'liquid'
+
+RubyVM::YJIT.enable
+
+EXPRESSIONS = [
+  "foo[1..2].baz",
+  "12.0",
+  "foo.bar.based",
+  "21 - 62",
+  "foo.bar.baz",
+  "foo > 12",
+  "foo < 12",
+  "foo <= 12",
+  "foo >= 12",
+  "foo <> 12",
+  "foo == 12",
+  "foo != 12",
+  "foo contains 12",
+  "foo contains 'bar'",
+  "foo != 'bar'",
+  "'foo' contains 'bar'",
+  '234089',
+  "foo | default: -1",
+]
+
+Benchmark.ips do |x|
+  x.config(time: 10, warmup: 5)
+
+  x.report("Liquid::Lexer#tokenize") do
+    EXPRESSIONS.each do |expr|
+      l = Liquid::Lexer.new(expr)
+      l.tokenize
+    end
+  end
+
+  x.compare!
+end

test/integration/assign_test.rb

@@ -6,51 +6,51 @@ class AssignTest < Minitest::Test
   include Liquid
 
   def test_assign_with_hyphen_in_variable_name
-    template_source = <<-END_TEMPLATE
-    {% assign this-thing = 'Print this-thing' %}
-    {{ this-thing }}
+    template_source = <<~END_TEMPLATE
+      {% assign this-thing = 'Print this-thing' -%}
+      {{ this-thing -}}
     END_TEMPLATE
-    template        = Template.parse(template_source)
-    rendered        = template.render!
-    assert_equal("Print this-thing", rendered.strip)
+    assert_template_result("Print this-thing", template_source)
   end
 
   def test_assigned_variable
-    assert_template_result('.foo.',
+    assert_template_result(
+      '.foo.',
       '{% assign foo = values %}.{{ foo[0] }}.',
-      'values' => %w(foo bar baz))
+      { 'values' => %w(foo bar baz) },
+    )
 
-    assert_template_result('.bar.',
+    assert_template_result(
+      '.bar.',
       '{% assign foo = values %}.{{ foo[1] }}.',
-      'values' => %w(foo bar baz))
+      { 'values' => %w(foo bar baz) },
+    )
   end
 
   def test_assign_with_filter
-    assert_template_result('.bar.',
+    assert_template_result(
+      '.bar.',
       '{% assign foo = values | split: "," %}.{{ foo[1] }}.',
-      'values' => "foo,bar,baz")
+      { 'values' => "foo,bar,baz" },
+    )
   end
 
   def test_assign_syntax_error
-    assert_match_syntax_error(/assign/,
-      '{% assign foo not values %}.',
-      'values' => "foo,bar,baz")
+    assert_match_syntax_error(/assign/, '{% assign foo not values %}.')
   end
 
   def test_assign_uses_error_mode
-    with_error_mode(:strict) do
-      assert_raises(SyntaxError) do
-        Template.parse("{% assign foo = ('X' | downcase) %}")
-      end
-    end
-    with_error_mode(:lax) do
-      assert(Template.parse("{% assign foo = ('X' | downcase) %}"))
-    end
+    assert_match_syntax_error(
+      "Expected dotdot but found pipe in ",
+      "{% assign foo = ('X' | downcase) %}",
+      error_mode: :strict,
+    )
+    assert_template_result("", "{% assign foo = ('X' | downcase) %}", error_mode: :lax)
   end
 
   def test_expression_with_whitespace_in_square_brackets
     source = "{% assign r = a[ 'b' ] %}{{ r }}"
-    assert_template_result('result', source, 'a' => { 'b' => 'result' })
+    assert_template_result('result', source, { 'a' => { 'b' => 'result' } })
   end
 
   def test_assign_score_exceeding_resource_limit

test/integration/blank_test.rb

@@ -9,12 +9,6 @@ class FoobarTag < Liquid::Tag
   end
 end
 
-class BlankTestFileSystem
-  def read_template_file(template_path)
-    template_path
-  end
-end
-
 class BlankTest < Minitest::Test
   include Liquid
   N = 10
@@ -33,7 +27,7 @@ class BlankTest < Minitest::Test
 
   def test_new_tags_are_not_blank_by_default
     with_custom_tag('foobar', FoobarTag) do
-      assert_template_result(" " * N, wrap_in_for("{% foobar %}"))
+      assert_equal(" " * N, Liquid::Template.parse(wrap_in_for("{% foobar %}")).render!)
     end
   end
 
@@ -63,9 +57,11 @@ class BlankTest < Minitest::Test
 
   def test_nested_blocks_are_blank_but_only_if_all_children_are
     assert_template_result("", wrap(wrap(" ")))
-    assert_template_result("\n       but this is not " * (N + 1),
+    assert_template_result(
+      "\n       but this is not " * (N + 1),
       wrap('{% if true %} {% comment %} this is blank {% endcomment %} {% endif %}
-      {% if true %} but this is not {% endif %}'))
+      {% if true %} but this is not {% endif %}'),
+    )
   end
 
   def test_assigns_are_blank
@@ -95,10 +91,21 @@ class BlankTest < Minitest::Test
   end
 
   def test_include_is_blank
-    Liquid::Template.file_system = BlankTestFileSystem.new
-    assert_template_result("foobar" * (N + 1), wrap("{% include 'foobar' %}"))
-    assert_template_result(" foobar " * (N + 1), wrap("{% include ' foobar ' %}"))
-    assert_template_result("   " * (N + 1), wrap(" {% include ' ' %} "))
+    assert_template_result(
+      "foobar" * (N + 1),
+      wrap("{% include 'foobar' %}"),
+      partials: { 'foobar' => 'foobar' },
+    )
+    assert_template_result(
+      " foobar " * (N + 1),
+      wrap("{% include ' foobar ' %}"),
+      partials: { ' foobar ' => ' foobar ' },
+    )
+    assert_template_result(
+      "   " * (N + 1),
+      wrap(" {% include ' ' %} "),
+      partials: { ' ' => ' ' },
+    )
   end
 
   def test_case_is_blank

test/integration/block_test.rb

@@ -6,10 +6,8 @@ class BlockTest < Minitest::Test
   include Liquid
 
   def test_unexpected_end_tag
-    exc = assert_raises(SyntaxError) do
-      Template.parse("{% if true %}{% endunless %}")
-    end
-    assert_equal(exc.message, "Liquid syntax error: 'endunless' is not a valid delimiter for if tags. use endif")
+    source = '{% if true %}{% endunless %}'
+    assert_match_syntax_error("Liquid syntax error (line 1): 'endunless' is not a valid delimiter for if tags. use endif", source)
   end
 
   def test_with_custom_tag

test/integration/capture_test.rb

@@ -10,44 +10,38 @@ class CaptureTest < Minitest::Test
   end
 
   def test_capture_with_hyphen_in_variable_name
-    template_source = <<-END_TEMPLATE
-    {% capture this-thing %}Print this-thing{% endcapture %}
-    {{ this-thing }}
+    template_source = <<~END_TEMPLATE
+      {% capture this-thing %}Print this-thing{% endcapture -%}
+      {{ this-thing -}}
     END_TEMPLATE
-    template        = Template.parse(template_source)
-    rendered        = template.render!
-    assert_equal("Print this-thing", rendered.strip)
+    assert_template_result("Print this-thing", template_source)
   end
 
   def test_capture_to_variable_from_outer_scope_if_existing
-    template_source = <<-END_TEMPLATE
-    {% assign var = '' %}
-    {% if true %}
-    {% capture var %}first-block-string{% endcapture %}
-    {% endif %}
-    {% if true %}
-    {% capture var %}test-string{% endcapture %}
-    {% endif %}
-    {{var}}
+    template_source = <<~END_TEMPLATE
+      {% assign var = '' -%}
+      {% if true -%}
+        {% capture var %}first-block-string{% endcapture -%}
+      {% endif -%}
+      {% if true -%}
+        {% capture var %}test-string{% endcapture -%}
+      {% endif -%}
+      {{var-}}
     END_TEMPLATE
-    template        = Template.parse(template_source)
-    rendered        = template.render!
-    assert_equal("test-string", rendered.gsub(/\s/, ''))
+    assert_template_result("test-string", template_source)
   end
 
   def test_assigning_from_capture
-    template_source = <<-END_TEMPLATE
-    {% assign first = '' %}
-    {% assign second = '' %}
-    {% for number in (1..3) %}
-    {% capture first %}{{number}}{% endcapture %}
-    {% assign second = first %}
-    {% endfor %}
-    {{ first }}-{{ second }}
+    template_source = <<~END_TEMPLATE
+      {% assign first = '' -%}
+      {% assign second = '' -%}
+      {% for number in (1..3) -%}
+        {% capture first %}{{number}}{% endcapture -%}
+        {% assign second = first -%}
+      {% endfor -%}
+      {{ first }}-{{ second -}}
     END_TEMPLATE
-    template        = Template.parse(template_source)
-    rendered        = template.render!
-    assert_equal("3-3", rendered.gsub(/\s/, ''))
+    assert_template_result("3-3", template_source)
   end
 
   def test_increment_assign_score_by_bytes_not_characters

test/integration/context_test.rb

@@ -24,7 +24,7 @@ class ContextSensitiveDrop < Liquid::Drop
   end
 end
 
-class Category < Liquid::Drop
+class Category
   attr_accessor :name
 
   def initialize(name)
@@ -36,8 +36,27 @@ class Category < Liquid::Drop
   end
 end
 
-class CategoryDrop
+class ProductsDrop < Liquid::Drop
+  def initialize(products)
+    @products = products
+  end
+
+  def size
+    @products.size
+  end
+
+  def to_liquid
+    if @context["forloop"]
+      @products.first(@context["forloop"].length)
+    else
+      @products
+    end
+  end
+end
+
+class CategoryDrop < Liquid::Drop
   attr_accessor :category, :context
+
   def initialize(category)
     @category = category
   end
@@ -101,7 +120,7 @@ class ContextTest < Minitest::Test
   end
 
   def test_variables_not_existing
-    assert_nil(@context['does_not_exist'])
+    assert_template_result("true", "{% if does_not_exist == nil %}true{% endif %}")
   end
 
   def test_scoping
@@ -120,22 +139,27 @@ class ContextTest < Minitest::Test
   end
 
   def test_length_query
-    @context['numbers'] = [1, 2, 3, 4]
+    assert_template_result(
+      "true",
+      "{% if numbers.size == 4 %}true{% endif %}",
+      { "numbers" => [1, 2, 3, 4] },
+    )
 
-    assert_equal(4, @context['numbers.size'])
+    assert_template_result(
+      "true",
+      "{% if numbers.size == 4 %}true{% endif %}",
+      { "numbers" => { 1 => 1, 2 => 2, 3 => 3, 4 => 4 } },
+    )
 
-    @context['numbers'] = { 1 => 1, 2 => 2, 3 => 3, 4 => 4 }
-
-    assert_equal(4, @context['numbers.size'])
-
-    @context['numbers'] = { 1 => 1, 2 => 2, 3 => 3, 4 => 4, 'size' => 1000 }
-
-    assert_equal(1000, @context['numbers.size'])
+    assert_template_result(
+      "true",
+      "{% if numbers.size == 1000 %}true{% endif %}",
+      { "numbers" => { 1 => 1, 2 => 2, 3 => 3, 4 => 4, 'size' => 1000 } },
+    )
   end
 
   def test_hyphenated_variable
-    @context['oh-my'] = 'godz'
-    assert_equal('godz', @context['oh-my'])
+    assert_template_result("godz", "{{ oh-my }}", { "oh-my" => 'godz' })
   end
 
   def test_add_filter
@@ -187,24 +211,24 @@ class ContextTest < Minitest::Test
   end
 
   def test_hierachical_data
-    @context['hash'] = { "name" => 'tobi' }
-    assert_equal('tobi', @context['hash.name'])
-    assert_equal('tobi', @context['hash["name"]'])
+    assigns = { 'hash' => { "name" => 'tobi' } }
+    assert_template_result("tobi", "{{ hash.name }}", assigns)
+    assert_template_result("tobi", '{{ hash["name"] }}', assigns)
   end
 
   def test_keywords
-    assert_equal(true, @context['true'])
-    assert_equal(false, @context['false'])
+    assert_template_result("pass", "{% if true == expect %}pass{% endif %}", { "expect" => true })
+    assert_template_result("pass", "{% if false == expect %}pass{% endif %}", { "expect" => false })
   end
 
   def test_digits
-    assert_equal(100, @context['100'])
-    assert_equal(100.00, @context['100.00'])
+    assert_template_result("pass", "{% if 100 == expect %}pass{% endif %}", { "expect" => 100 })
+    assert_template_result("pass", "{% if 100.00 == expect %}pass{% endif %}", { "expect" => 100.00 })
   end
 
   def test_strings
-    assert_equal("hello!", @context['"hello!"'])
-    assert_equal("hello!", @context["'hello!'"])
+    assert_template_result("hello!", '{{ "hello!" }}')
+    assert_template_result("hello!", "{{ 'hello!' }}")
   end
 
   def test_merge
@@ -216,99 +240,92 @@ class ContextTest < Minitest::Test
   end
 
   def test_array_notation
-    @context['test'] = [1, 2, 3, 4, 5]
-
-    assert_equal(1, @context['test[0]'])
-    assert_equal(2, @context['test[1]'])
-    assert_equal(3, @context['test[2]'])
-    assert_equal(4, @context['test[3]'])
-    assert_equal(5, @context['test[4]'])
+    assigns = { "test" => ["a", "b"] }
+    assert_template_result("a", "{{ test[0] }}", assigns)
+    assert_template_result("b", "{{ test[1] }}", assigns)
+    assert_template_result("pass", "{% if test[2] == nil %}pass{% endif %}", assigns)
   end
 
   def test_recoursive_array_notation
-    @context['test'] = { 'test' => [1, 2, 3, 4, 5] }
+    assigns = { "test" => { 'test' => [1, 2, 3, 4, 5] } }
+    assert_template_result("1", "{{ test.test[0] }}", assigns)
 
-    assert_equal(1, @context['test.test[0]'])
-
-    @context['test'] = [{ 'test' => 'worked' }]
-
-    assert_equal('worked', @context['test[0].test'])
+    assigns = { "test" => [{ 'test' => 'worked' }] }
+    assert_template_result("worked", "{{ test[0].test }}", assigns)
   end
 
   def test_hash_to_array_transition
-    @context['colors'] = {
-      'Blue' => ['003366', '336699', '6699CC', '99CCFF'],
-      'Green' => ['003300', '336633', '669966', '99CC99'],
-      'Yellow' => ['CC9900', 'FFCC00', 'FFFF99', 'FFFFCC'],
-      'Red' => ['660000', '993333', 'CC6666', 'FF9999'],
+    assigns = {
+      'colors' => {
+        'Blue' => ['003366', '336699', '6699CC', '99CCFF'],
+        'Green' => ['003300', '336633', '669966', '99CC99'],
+        'Yellow' => ['CC9900', 'FFCC00', 'FFFF99', 'FFFFCC'],
+        'Red' => ['660000', '993333', 'CC6666', 'FF9999'],
+      },
     }
 
-    assert_equal('003366', @context['colors.Blue[0]'])
-    assert_equal('FF9999', @context['colors.Red[3]'])
+    assert_template_result("003366", "{{ colors.Blue[0] }}", assigns)
+    assert_template_result("FF9999", "{{ colors.Red[3] }}", assigns)
   end
 
   def test_try_first
-    @context['test'] = [1, 2, 3, 4, 5]
+    assigns = { 'test' => [1, 2, 3, 4, 5] }
+    assert_template_result("1", "{{ test.first }}", assigns)
+    assert_template_result("pass", "{% if test.last == 5 %}pass{% endif %}", assigns)
 
-    assert_equal(1, @context['test.first'])
-    assert_equal(5, @context['test.last'])
+    assigns = { "test" => { "test" => [1, 2, 3, 4, 5] } }
+    assert_template_result("1", "{{ test.test.first }}", assigns)
+    assert_template_result("5", "{{ test.test.last }}", assigns)
 
-    @context['test'] = { 'test' => [1, 2, 3, 4, 5] }
-
-    assert_equal(1, @context['test.test.first'])
-    assert_equal(5, @context['test.test.last'])
-
-    @context['test'] = [1]
-    assert_equal(1, @context['test.first'])
-    assert_equal(1, @context['test.last'])
+    assigns = { "test" => [1] }
+    assert_template_result("1", "{{ test.first }}", assigns)
+    assert_template_result("1", "{{ test.last }}", assigns)
   end
 
   def test_access_hashes_with_hash_notation
-    @context['products'] = { 'count' => 5, 'tags' => ['deepsnow', 'freestyle'] }
-    @context['product']  = { 'variants' => [{ 'title' => 'draft151cm' }, { 'title' => 'element151cm' }] }
+    assigns = { 'products' => { 'count' => 5, 'tags' => ['deepsnow', 'freestyle'] } }
+    assert_template_result("5", '{{ products["count"] }}', assigns)
+    assert_template_result("deepsnow", '{{ products["tags"][0] }}', assigns)
+    assert_template_result("deepsnow", '{{ products["tags"].first }}', assigns)
 
-    assert_equal(5, @context['products["count"]'])
-    assert_equal('deepsnow', @context['products["tags"][0]'])
-    assert_equal('deepsnow', @context['products["tags"].first'])
-    assert_equal('draft151cm', @context['product["variants"][0]["title"]'])
-    assert_equal('element151cm', @context['product["variants"][1]["title"]'])
-    assert_equal('draft151cm', @context['product["variants"][0]["title"]'])
-    assert_equal('element151cm', @context['product["variants"].last["title"]'])
+    assigns = { 'product' => { 'variants' => [{ 'title' => 'draft151cm' }, { 'title' => 'element151cm' }] } }
+    assert_template_result("draft151cm", '{{ product["variants"][0]["title"] }}', assigns)
+    assert_template_result("element151cm", '{{ product["variants"][1]["title"] }}', assigns)
+    assert_template_result("draft151cm", '{{ product["variants"].first["title"] }}', assigns)
+    assert_template_result("element151cm", '{{ product["variants"].last["title"] }}', assigns)
   end
 
   def test_access_variable_with_hash_notation
-    @context['foo'] = 'baz'
-    @context['bar'] = 'foo'
-
-    assert_equal('baz', @context['["foo"]'])
-    assert_equal('baz', @context['[bar]'])
+    assert_template_result('baz', '{{ ["foo"] }}', { "foo" => "baz" })
+    assert_template_result('baz', '{{ [bar] }}', { 'foo' => 'baz', 'bar' => 'foo' })
   end
 
   def test_access_hashes_with_hash_access_variables
-    @context['var']      = 'tags'
-    @context['nested']   = { 'var' => 'tags' }
-    @context['products'] = { 'count' => 5, 'tags' => ['deepsnow', 'freestyle'] }
+    assigns = {
+      'var' => 'tags',
+      'nested' => { 'var' => 'tags' },
+      'products' => { 'count' => 5, 'tags' => ['deepsnow', 'freestyle'] },
+    }
 
-    assert_equal('deepsnow', @context['products[var].first'])
-    assert_equal('freestyle', @context['products[nested.var].last'])
+    assert_template_result('deepsnow', '{{ products[var].first }}', assigns)
+    assert_template_result('freestyle', '{{ products[nested.var].last }}', assigns)
   end
 
   def test_hash_notation_only_for_hash_access
-    @context['array'] = [1, 2, 3, 4, 5]
-    @context['hash']  = { 'first' => 'Hello' }
+    assigns = { "array" => [1, 2, 3, 4, 5] }
+    assert_template_result("1", "{{ array.first }}", assigns)
+    assert_template_result("pass", '{% if array["first"] == nil %}pass{% endif %}', assigns)
 
-    assert_equal(1, @context['array.first'])
-    assert_nil(@context['array["first"]'])
-    assert_equal('Hello', @context['hash["first"]'])
+    assert_template_result("Hello", '{{ hash["first"] }}', { "hash" => { "first" => "Hello" } })
   end
 
   def test_first_can_appear_in_middle_of_callchain
-    @context['product'] = { 'variants' => [{ 'title' => 'draft151cm' }, { 'title' => 'element151cm' }] }
+    assigns = { "product" => { 'variants' => [{ 'title' => 'draft151cm' }, { 'title' => 'element151cm' }] } }
 
-    assert_equal('draft151cm', @context['product.variants[0].title'])
-    assert_equal('element151cm', @context['product.variants[1].title'])
-    assert_equal('draft151cm', @context['product.variants.first.title'])
-    assert_equal('element151cm', @context['product.variants.last.title'])
+    assert_template_result('draft151cm', '{{ product.variants[0].title }}', assigns)
+    assert_template_result('element151cm', '{{ product.variants[1].title }}', assigns)
+    assert_template_result('draft151cm', '{{ product.variants.first.title }}', assigns)
+    assert_template_result('element151cm', '{{ product.variants.last.title }}', assigns)
   end
 
   def test_cents
@@ -350,10 +367,12 @@ class ContextTest < Minitest::Test
   end
 
   def test_ranges
-    @context.merge("test" => '5')
-    assert_equal((1..5), @context['(1..5)'])
-    assert_equal((1..5), @context['(1..test)'])
-    assert_equal((5..5), @context['(test..test)'])
+    assert_template_result("1..5", '{{ (1..5) }}')
+    assert_template_result("pass", '{% if (1..5) == expect %}pass{% endif %}', { "expect" => (1..5) })
+
+    assigns = { "test" => '5' }
+    assert_template_result("1..5", "{{ (1..test) }}", assigns)
+    assert_template_result("5..5", "{{ (test..test) }}", assigns)
   end
 
   def test_cents_through_drop_nestedly
@@ -405,45 +424,45 @@ class ContextTest < Minitest::Test
   end
 
   def test_lambda_is_called_once
+    @global = 0
+
     @context['callcount'] = proc {
-      @global ||= 0
-      @global  += 1
+      @global += 1
       @global.to_s
     }
 
     assert_equal('1', @context['callcount'])
     assert_equal('1', @context['callcount'])
     assert_equal('1', @context['callcount'])
-
-    @global = nil
   end
 
   def test_nested_lambda_is_called_once
-    @context['callcount'] = { "lambda" => proc {
-                                            @global ||= 0
-                                            @global  += 1
-                                            @global.to_s
-                                          } }
+    @global = 0
+
+    @context['callcount'] = {
+      "lambda" => proc {
+                    @global += 1
+                    @global.to_s
+                  },
+    }
 
     assert_equal('1', @context['callcount.lambda'])
     assert_equal('1', @context['callcount.lambda'])
     assert_equal('1', @context['callcount.lambda'])
-
-    @global = nil
   end
 
   def test_lambda_in_array_is_called_once
-    @context['callcount'] = [1, 2, proc {
-                                     @global ||= 0
-                                     @global  += 1
-                                     @global.to_s
-                                   }, 4, 5]
+    @global = 0
+
+    p = proc {
+      @global += 1
+      @global.to_s
+    }
+    @context['callcount'] = [1, 2, p, 4, 5]
 
     assert_equal('1', @context['callcount[2]'])
     assert_equal('1', @context['callcount[2]'])
     assert_equal('1', @context['callcount[2]'])
-
-    @global = nil
   end
 
   def test_access_to_context_from_proc
@@ -461,6 +480,7 @@ class ContextTest < Minitest::Test
   end
 
   def test_interrupt_avoids_object_allocations
+    @context.interrupt? # ruby 3.0.0 allocates on the first call
     assert_no_object_allocations do
       @context.interrupt?
     end
@@ -485,7 +505,7 @@ class ContextTest < Minitest::Test
   def test_static_environments_are_read_with_lower_priority_than_environments
     context = Context.build(
       static_environments: { 'shadowed' => 'static', 'unshadowed' => 'static' },
-      environments: { 'shadowed' => 'dynamic' }
+      environments: { 'shadowed' => 'dynamic' },
     )
 
     assert_equal('dynamic', context['shadowed'])
@@ -530,7 +550,7 @@ class ContextTest < Minitest::Test
     registers = {
       my_register: :my_value,
     }
-    super_context = Context.new({}, {}, StaticRegisters.new(registers))
+    super_context = Context.new({}, {}, Registers.new(registers))
     super_context.registers[:my_register] = :my_alt_value
     subcontext                            = super_context.new_isolated_subcontext
     assert_equal(:my_value, subcontext.registers[:my_register])
@@ -619,6 +639,54 @@ class ContextTest < Minitest::Test
     end
   end
 
+  def test_context_always_uses_static_registers
+    registers = {
+      my_register: :my_value,
+    }
+    c = Context.new({}, {}, registers)
+    assert_instance_of(Registers, c.registers)
+    assert_equal(:my_value, c.registers[:my_register])
+
+    r = Registers.new(registers)
+    c = Context.new({}, {}, r)
+    assert_instance_of(Registers, c.registers)
+    assert_equal(:my_value, c.registers[:my_register])
+  end
+
+  def test_variable_to_liquid_returns_contextual_drop
+    context = {
+      "products" => ProductsDrop.new(["A", "B", "C", "D", "E"]),
+    }
+
+    template = Liquid::Template.parse(<<~LIQUID)
+      {%- for i in (1..3) -%}
+        for_loop_products_count: {{ products | size }}
+      {% endfor %}
+
+      unscoped_products_count: {{ products | size }}
+    LIQUID
+
+    result = template.render(context)
+
+    assert_includes(result, "for_loop_products_count: 3")
+    assert_includes(result, "unscoped_products_count: 5")
+  end
+
+  def test_new_isolated_context_inherits_parent_environment
+    global_environment = Liquid::Environment.build(tags: {})
+    context = Context.build(environment: global_environment)
+
+    subcontext = context.new_isolated_subcontext
+    assert_equal(global_environment, subcontext.environment)
+  end
+
+  def test_newly_built_context_inherits_parent_environment
+    global_environment = Liquid::Environment.build(tags: {})
+    context = Context.build(environment: global_environment)
+    assert_equal(global_environment, context.environment)
+    assert(context.environment.tags.each.to_a.empty?)
+  end
+
   private
 
   def assert_no_object_allocations

test/integration/document_test.rb

@@ -6,16 +6,12 @@ class DocumentTest < Minitest::Test
   include Liquid
 
   def test_unexpected_outer_tag
-    exc = assert_raises(SyntaxError) do
-      Template.parse("{% else %}")
-    end
-    assert_equal(exc.message, "Liquid syntax error: Unexpected outer 'else' tag")
+    source = "{% else %}"
+    assert_match_syntax_error("Liquid syntax error (line 1): Unexpected outer 'else' tag", source)
   end
 
   def test_unknown_tag
-    exc = assert_raises(SyntaxError) do
-      Template.parse("{% foo %}")
-    end
-    assert_equal(exc.message, "Liquid syntax error: Unknown tag 'foo'")
+    source = "{% foo %}"
+    assert_match_syntax_error("Liquid syntax error (line 1): Unknown tag 'foo'", source)
   end
 end

test/integration/error_handling_test.rb

@@ -63,9 +63,7 @@ class ErrorHandlingTest < Minitest::Test
   end
 
   def test_missing_endtag_parse_time_error
-    assert_raises(Liquid::SyntaxError) do
-      Liquid::Template.parse(' {% for a in b %} ... ')
-    end
+    assert_match_syntax_error(/: 'for' tag was never closed\z/, ' {% for a in b %} ... ')
   end
 
   def test_unrecognized_operator
@@ -84,37 +82,31 @@ class ErrorHandlingTest < Minitest::Test
   end
 
   def test_with_line_numbers_adds_numbers_to_parser_errors
-    err = assert_raises(SyntaxError) do
-      Liquid::Template.parse('
-          foobar
+    source = <<~LIQUID
+      foobar
 
-          {% "cat" | foobar %}
+      {% "cat" | foobar %}
 
-          bla
-        ',
-        line_numbers: true)
-    end
-
-    assert_match(/Liquid syntax error \(line 4\)/, err.message)
+      bla
+    LIQUID
+    assert_match_syntax_error(/Liquid syntax error \(line 3\)/, source)
   end
 
   def test_with_line_numbers_adds_numbers_to_parser_errors_with_whitespace_trim
-    err = assert_raises(SyntaxError) do
-      Liquid::Template.parse('
-          foobar
+    source = <<~LIQUID
+      foobar
 
-          {%- "cat" | foobar -%}
+      {%- "cat" | foobar -%}
 
-          bla
-        ',
-        line_numbers: true)
-    end
+      bla
+    LIQUID
 
-    assert_match(/Liquid syntax error \(line 4\)/, err.message)
+    assert_match_syntax_error(/Liquid syntax error \(line 3\)/, source)
   end
 
   def test_parsing_warn_with_line_numbers_adds_numbers_to_lexer_errors
-    template = Liquid::Template.parse('
+    template = Liquid::Template.parse(
+      '
         foobar
 
         {% if 1 =! 2 %}ok{% endif %}
@@ -122,15 +114,19 @@ class ErrorHandlingTest < Minitest::Test
         bla
             ',
       error_mode: :warn,
-      line_numbers: true)
+      line_numbers: true,
+    )
 
-    assert_equal(['Liquid syntax error (line 4): Unexpected character = in "1 =! 2"'],
-      template.warnings.map(&:message))
+    assert_equal(
+      ['Liquid syntax error (line 4): Unexpected character = in "1 =! 2"'],
+      template.warnings.map(&:message),
+    )
   end
 
   def test_parsing_strict_with_line_numbers_adds_numbers_to_lexer_errors
     err = assert_raises(SyntaxError) do
-      Liquid::Template.parse('
+      Liquid::Template.parse(
+        '
           foobar
 
           {% if 1 =! 2 %}ok{% endif %}
@@ -138,27 +134,25 @@ class ErrorHandlingTest < Minitest::Test
           bla
                 ',
         error_mode: :strict,
-        line_numbers: true)
+        line_numbers: true,
+      )
     end
 
     assert_equal('Liquid syntax error (line 4): Unexpected character = in "1 =! 2"', err.message)
   end
 
   def test_syntax_errors_in_nested_blocks_have_correct_line_number
-    err = assert_raises(SyntaxError) do
-      Liquid::Template.parse('
-          foobar
+    source = <<~LIQUID
+      foobar
 
-          {% if 1 != 2 %}
-            {% foo %}
-          {% endif %}
+      {% if 1 != 2 %}
+        {% foo %}
+      {% endif %}
 
-          bla
-                ',
-        line_numbers: true)
-    end
+      bla
+    LIQUID
 
-    assert_equal("Liquid syntax error (line 5): Unknown tag 'foo'", err.message)
+    assert_match_syntax_error("Liquid syntax error (line 4): Unknown tag 'foo'", source)
   end
 
   def test_strict_error_messages
@@ -209,20 +203,34 @@ class ErrorHandlingTest < Minitest::Test
   end
 
   def test_setting_default_exception_renderer
-    old_exception_renderer = Liquid::Template.default_exception_renderer
     exceptions = []
-    Liquid::Template.default_exception_renderer = ->(e) {
+    default_exception_renderer = ->(e) {
       exceptions << e
       ''
     }
-    template = Liquid::Template.parse('This is a runtime error: {{ errors.argument_error }}')
+
+    env = Liquid::Environment.build(exception_renderer: default_exception_renderer)
+    template = Liquid::Template.parse('This is a runtime error: {{ errors.argument_error }}', environment: env)
 
     output = template.render('errors' => ErrorDrop.new)
 
     assert_equal('This is a runtime error: ', output)
     assert_equal([Liquid::ArgumentError], template.errors.map(&:class))
-  ensure
-    Liquid::Template.default_exception_renderer = old_exception_renderer if old_exception_renderer
+  end
+
+  def test_setting_exception_renderer_on_environment
+    exceptions = []
+    exception_renderer = ->(e) do
+      exceptions << e
+      ''
+    end
+
+    environment = Liquid::Environment.build(exception_renderer: exception_renderer)
+    template = Liquid::Template.parse('This is a runtime error: {{ errors.argument_error }}', environment: environment)
+    output = template.render('errors' => ErrorDrop.new)
+
+    assert_equal('This is a runtime error: ', output)
+    assert_equal([Liquid::ArgumentError], template.errors.map(&:class))
   end
 
   def test_exception_renderer_exposing_non_liquid_error
@@ -248,16 +256,10 @@ class ErrorHandlingTest < Minitest::Test
   end
 
   def test_included_template_name_with_line_numbers
-    old_file_system = Liquid::Template.file_system
+    environment = Liquid::Environment.build(file_system: TestFileSystem.new)
+    template = Liquid::Template.parse("Argument error:\n{% include 'product' %}", line_numbers: true, environment: environment)
+    page     = template.render('errors' => ErrorDrop.new)
 
-    begin
-      Liquid::Template.file_system = TestFileSystem.new
-
-      template = Liquid::Template.parse("Argument error:\n{% include 'product' %}", line_numbers: true)
-      page     = template.render('errors' => ErrorDrop.new)
-    ensure
-      Liquid::Template.file_system = old_file_system
-    end
     assert_equal("Argument error:\nLiquid error (product line 1): argument error", page)
     assert_equal("product", template.errors.first.template_name)
   end
@@ -269,4 +271,81 @@ class ErrorHandlingTest < Minitest::Test
     output = Liquid::Template.parse("{% assign x = 0 %}{% if 1 < '2' %}{% assign x = 3 %}{% endif %}{{ x }}").render
     assert_equal("0", output)
   end
+
+  def test_syntax_error_is_raised_with_template_name
+    file_system = StubFileSystem.new("snippet" => "1\n2\n{{ 1")
+
+    context = Liquid::Context.build(
+      registers: { file_system: file_system },
+    )
+
+    template = Template.parse(
+      '{% render "snippet" %}',
+      line_numbers: true,
+    )
+    template.name = "template/index"
+
+    assert_equal(
+      "Liquid syntax error (snippet line 3): Variable '{{' was not properly terminated with regexp: /\\}\\}/",
+      template.render(context),
+    )
+  end
+
+  def test_syntax_error_is_raised_with_template_name_from_template_factory
+    file_system = StubFileSystem.new("snippet" => "1\n2\n{{ 1")
+
+    context = Liquid::Context.build(
+      registers: {
+        file_system: file_system,
+        template_factory: StubTemplateFactory.new,
+      },
+    )
+
+    template = Template.parse(
+      '{% render "snippet" %}',
+      line_numbers: true,
+    )
+    template.name = "template/index"
+
+    assert_equal(
+      "Liquid syntax error (some/path/snippet line 3): Variable '{{' was not properly terminated with regexp: /\\}\\}/",
+      template.render(context),
+    )
+  end
+
+  def test_error_is_raised_during_parse_with_template_name
+    depth = Liquid::Block::MAX_DEPTH + 1
+    code = "{% if true %}" * depth + "rendered" + "{% endif %}" * depth
+
+    template = Template.parse("{% render 'snippet' %}", line_numbers: true)
+
+    context = Liquid::Context.build(
+      registers: {
+        file_system: StubFileSystem.new("snippet" => code),
+        template_factory: StubTemplateFactory.new,
+      },
+    )
+
+    assert_equal("Liquid error (some/path/snippet line 1): Nesting too deep", template.render(context))
+  end
+
+  def test_internal_error_is_raised_with_template_name
+    template = Template.new
+    template.parse(
+      "{% render 'snippet' %}",
+      line_numbers: true,
+    )
+    template.name = "template/index"
+
+    context = Liquid::Context.build(
+      registers: {
+        file_system: StubFileSystem.new({}),
+      },
+    )
+
+    assert_equal(
+      "Liquid error (template/index line 1): internal",
+      template.render(context),
+    )
+  end
 end

test/integration/expression_test.rb

@@ -1,46 +1,156 @@
 # frozen_string_literal: true
 
 require 'test_helper'
+require 'lru_redux'
 
 class ExpressionTest < Minitest::Test
   def test_keyword_literals
-    assert_equal(true, parse_and_eval("true"))
-    assert_equal(true, parse_and_eval(" true "))
+    assert_template_result("true", "{{ true }}")
+    assert_expression_result(true, "true")
   end
 
   def test_string
-    assert_equal("single quoted", parse_and_eval("'single quoted'"))
-    assert_equal("double quoted", parse_and_eval('"double quoted"'))
-    assert_equal("spaced", parse_and_eval(" 'spaced' "))
-    assert_equal("spaced2", parse_and_eval(' "spaced2" '))
+    assert_template_result("single quoted", "{{'single quoted'}}")
+    assert_template_result("double quoted", '{{"double quoted"}}')
+    assert_template_result("spaced", "{{ 'spaced' }}")
+    assert_template_result("spaced2", "{{ 'spaced2' }}")
+    assert_template_result("emoji🔥", "{{ 'emoji🔥' }}")
   end
 
   def test_int
-    assert_equal(123, parse_and_eval("123"))
-    assert_equal(456, parse_and_eval(" 456 "))
-    assert_equal(12, parse_and_eval("012"))
+    assert_template_result("456", "{{ 456 }}")
+    assert_expression_result(123, "123")
+    assert_expression_result(12, "012")
   end
 
   def test_float
-    assert_equal(1.5, parse_and_eval("1.5"))
-    assert_equal(2.5, parse_and_eval(" 2.5 "))
+    assert_template_result("-17.42", "{{ -17.42 }}")
+    assert_template_result("2.5", "{{ 2.5 }}")
+    assert_expression_result(0.0, "0.....5")
+    assert_expression_result(0.0, "-0..1")
+    assert_expression_result(1.5, "1.5")
+
+    # this is a unfortunate quirky behavior of Liquid
+    result = Expression.parse(".5")
+    assert_kind_of(Liquid::VariableLookup, result)
+
+    result = Expression.parse("-.5")
+    assert_kind_of(Liquid::VariableLookup, result)
   end
 
   def test_range
-    assert_equal(1..2, parse_and_eval("(1..2)"))
-    assert_equal(3..4, parse_and_eval(" ( 3 .. 4 ) "))
+    assert_template_result("3..4", "{{ ( 3 .. 4 ) }}")
+    assert_expression_result(1..2, "(1..2)")
+
+    assert_match_syntax_error(
+      "Liquid syntax error (line 1): Invalid expression type 'false' in range expression",
+      "{{ (false..true) }}",
+    )
+    assert_match_syntax_error(
+      "Liquid syntax error (line 1): Invalid expression type '(1..2)' in range expression",
+      "{{ ((1..2)..3) }}",
+    )
+  end
+
+  def test_quirky_negative_sign_expression_markup
+    result = Expression.parse("-", nil)
+    assert(result.is_a?(VariableLookup))
+    assert_equal("-", result.name)
+
+    # for this template, the expression markup is "-"
+    assert_template_result(
+      "",
+      "{{ - 'theme.css' - }}",
+    )
+  end
+
+  def test_expression_cache
+    skip("Liquid-C does not support Expression caching") if defined?(Liquid::C) && Liquid::C.enabled
+
+    cache = {}
+    template = <<~LIQUID
+      {% assign x = 1 %}
+      {{ x }}
+      {% assign x = 2 %}
+      {{ x }}
+      {% assign y = 1 %}
+      {{ y }}
+    LIQUID
+
+    Liquid::Template.parse(template, expression_cache: cache).render
+
+    assert_equal(
+      ["1", "2", "x", "y"],
+      cache.to_a.map { _1[0] }.sort,
+    )
+  end
+
+  def test_expression_cache_with_true_boolean
+    skip("Liquid-C does not support Expression caching") if defined?(Liquid::C) && Liquid::C.enabled
+
+    template = <<~LIQUID
+      {% assign x = 1 %}
+      {{ x }}
+      {% assign x = 2 %}
+      {{ x }}
+      {% assign y = 1 %}
+      {{ y }}
+    LIQUID
+
+    parse_context = ParseContext.new(expression_cache: true)
+
+    Liquid::Template.parse(template, parse_context).render
+
+    cache = parse_context.instance_variable_get(:@expression_cache)
+
+    assert_equal(
+      ["1", "2", "x", "y"],
+      cache.to_a.map { _1[0] }.sort,
+    )
+  end
+
+  def test_expression_cache_with_lru_redux
+    skip("Liquid-C does not support Expression caching") if defined?(Liquid::C) && Liquid::C.enabled
+
+    cache = LruRedux::Cache.new(10)
+    template = <<~LIQUID
+      {% assign x = 1 %}
+      {{ x }}
+      {% assign x = 2 %}
+      {{ x }}
+      {% assign y = 1 %}
+      {{ y }}
+    LIQUID
+
+    Liquid::Template.parse(template, expression_cache: cache).render
+
+    assert_equal(
+      ["1", "2", "x", "y"],
+      cache.to_a.map { _1[0] }.sort,
+    )
+  end
+
+  def test_disable_expression_cache
+    skip("Liquid-C does not support Expression caching") if defined?(Liquid::C) && Liquid::C.enabled
+
+    template = <<~LIQUID
+      {% assign x = 1 %}
+      {{ x }}
+      {% assign x = 2 %}
+      {{ x }}
+      {% assign y = 1 %}
+      {{ y }}
+    LIQUID
+
+    parse_context = Liquid::ParseContext.new(expression_cache: false)
+    Liquid::Template.parse(template, parse_context).render
+    assert(parse_context.instance_variable_get(:@expression_cache).nil?)
   end
 
   private
 
-  def parse_and_eval(markup, **assigns)
-    if Liquid::Template.error_mode == :strict
-      p = Liquid::Parser.new(markup)
-      markup = p.expression
-      p.consume(:end_of_string)
-    end
-    expression = Liquid::Expression.parse(markup)
-    context = Liquid::Context.new(assigns)
-    context.evaluate(expression)
+  def assert_expression_result(expect, markup, **assigns)
+    liquid = "{% if expect == #{markup} %}pass{% else %}got {{ #{markup} }}{% endif %}"
+    assert_template_result("pass", liquid, { "expect" => expect, **assigns })
   end
 end

test/integration/filter_kwarg_test.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class FilterKwargTest < Minitest::Test
+  module KwargFilter
+    def html_tag(_tag, attributes)
+      attributes
+        .map { |key, value| "#{key}='#{value}'" }
+        .join(' ')
+    end
+  end
+
+  include Liquid
+
+  def test_can_parse_data_kwargs
+    with_global_filter(KwargFilter) do
+      assert_equal(
+        "data-src='src' data-widths='100, 200'",
+        Template.parse("{{ 'img' | html_tag: data-src: 'src', data-widths: '100, 200' }}").render(nil, nil),
+      )
+    end
+  end
+end

test/integration/filter_test.rb

@@ -59,84 +59,87 @@ class FiltersTest < Minitest::Test
   end
 
   def test_size
-    @context['var'] = 'abcd'
-    @context.add_filters(MoneyFilter)
-
-    assert_equal('4', Template.parse("{{var | size}}").render(@context))
+    assert_template_result("4", "{{var | size}}", { "var" => 'abcd' })
   end
 
   def test_join
-    @context['var'] = [1, 2, 3, 4]
-
-    assert_equal("1 2 3 4", Template.parse("{{var | join}}").render(@context))
+    assert_template_result("1 2 3 4", "{{var | join}}", { "var" => [1, 2, 3, 4] })
   end
 
   def test_sort
-    @context['value']   = 3
-    @context['numbers'] = [2, 1, 4, 3]
-    @context['words']   = ['expected', 'as', 'alphabetic']
-    @context['arrays']  = ['flower', 'are']
-    @context['case_sensitive'] = ['sensitive', 'Expected', 'case']
-
-    assert_equal('1 2 3 4', Template.parse("{{numbers | sort | join}}").render(@context))
-    assert_equal('alphabetic as expected', Template.parse("{{words | sort | join}}").render(@context))
-    assert_equal('3', Template.parse("{{value | sort}}").render(@context))
-    assert_equal('are flower', Template.parse("{{arrays | sort | join}}").render(@context))
-    assert_equal('Expected case sensitive', Template.parse("{{case_sensitive | sort | join}}").render(@context))
+    assert_template_result("1 2 3 4", "{{numbers | sort | join}}", { "numbers" => [2, 1, 4, 3] })
+    assert_template_result(
+      "alphabetic as expected",
+      "{{words | sort | join}}",
+      { "words" => ['expected', 'as', 'alphabetic'] },
+    )
+    assert_template_result("3", "{{value | sort}}", { "value" => 3 })
+    assert_template_result('are flower', "{{arrays | sort | join}}", { 'arrays' => ['flower', 'are'] })
+    assert_template_result(
+      "Expected case sensitive",
+      "{{case_sensitive | sort | join}}",
+      { "case_sensitive" => ["sensitive", "Expected", "case"] },
+    )
   end
 
   def test_sort_natural
-    @context['words']   = ['case', 'Assert', 'Insensitive']
-    @context['hashes']  = [{ 'a' => 'A' }, { 'a' => 'b' }, { 'a' => 'C' }]
-    @context['objects'] = [TestObject.new('A'), TestObject.new('b'), TestObject.new('C')]
-
     # Test strings
-    assert_equal('Assert case Insensitive', Template.parse("{{words | sort_natural | join}}").render(@context))
+    assert_template_result(
+      "Assert case Insensitive",
+      "{{words | sort_natural | join}}",
+      { "words" => ["case", "Assert", "Insensitive"] },
+    )
 
     # Test hashes
-    assert_equal('A b C', Template.parse("{{hashes | sort_natural: 'a' | map: 'a' | join}}").render(@context))
+    assert_template_result(
+      "A b C",
+      "{{hashes | sort_natural: 'a' | map: 'a' | join}}",
+      { "hashes" => [{ "a" => "A" }, { "a" => "b" }, { "a" => "C" }] },
+    )
 
     # Test objects
+    @context['objects'] = [TestObject.new('A'), TestObject.new('b'), TestObject.new('C')]
     assert_equal('A b C', Template.parse("{{objects | sort_natural: 'a' | map: 'a' | join}}").render(@context))
   end
 
   def test_compact
-    @context['words']   = ['a', nil, 'b', nil, 'c']
-    @context['hashes']  = [{ 'a' => 'A' }, { 'a' => nil }, { 'a' => 'C' }]
-    @context['objects'] = [TestObject.new('A'), TestObject.new(nil), TestObject.new('C')]
-
     # Test strings
-    assert_equal('a b c', Template.parse("{{words | compact | join}}").render(@context))
+    assert_template_result(
+      "a b c",
+      "{{words | compact | join}}",
+      { "words" => ['a', nil, 'b', nil, 'c'] },
+    )
 
     # Test hashes
-    assert_equal('A C', Template.parse("{{hashes | compact: 'a' | map: 'a' | join}}").render(@context))
+    assert_template_result(
+      "A C",
+      "{{hashes | compact: 'a' | map: 'a' | join}}",
+      { "hashes" => [{ "a" => "A" }, { "a" => nil }, { "a" => "C" }] },
+    )
 
     # Test objects
+    @context['objects'] = [TestObject.new('A'), TestObject.new(nil), TestObject.new('C')]
     assert_equal('A C', Template.parse("{{objects | compact: 'a' | map: 'a' | join}}").render(@context))
   end
 
   def test_strip_html
-    @context['var'] = "<b>bla blub</a>"
-
-    assert_equal("bla blub", Template.parse("{{ var | strip_html }}").render(@context))
+    assert_template_result("bla blub", "{{ var | strip_html }}", { "var" => "<b>bla blub</a>" })
   end
 
   def test_strip_html_ignore_comments_with_html
-    @context['var'] = "<!-- split and some <ul> tag --><b>bla blub</a>"
-
-    assert_equal("bla blub", Template.parse("{{ var | strip_html }}").render(@context))
+    assert_template_result(
+      "bla blub",
+      "{{ var | strip_html }}",
+      { "var" => "<!-- split and some <ul> tag --><b>bla blub</a>" },
+    )
   end
 
   def test_capitalize
-    @context['var'] = "blub"
-
-    assert_equal("Blub", Template.parse("{{ var | capitalize }}").render(@context))
+    assert_template_result("Blub", "{{ var | capitalize }}", { "var" => "blub" })
   end
 
   def test_nonexistent_filter_is_ignored
-    @context['var'] = 1000
-
-    assert_equal('1000', Template.parse("{{ var | xyzzy }}").render(@context))
+    assert_template_result("1000", "{{ var | xyzzy }}", { "var" => 1000 })
   end
 
   def test_filter_with_keyword_arguments

test/integration/output_test.rb

@@ -33,31 +33,25 @@ class OutputTest < Minitest::Test
 
   def setup
     @assigns = {
-      'best_cars' => 'bmw',
       'car' => { 'bmw' => 'good', 'gm' => 'bad' },
     }
   end
 
   def test_variable
-    text = %( {{best_cars}} )
-
-    expected = %( bmw )
-    assert_equal(expected, Template.parse(text).render!(@assigns))
+    assert_template_result(" bmw ", " {{best_cars}} ", { "best_cars" => "bmw" })
   end
 
   def test_variable_traversing_with_two_brackets
-    text = %({{ site.data.menu[include.menu][include.locale] }})
-    assert_equal("it works!", Template.parse(text).render!(
+    source = "{{ site.data.menu[include.menu][include.locale] }}"
+    assert_template_result("it works!", source, {
       "site" => { "data" => { "menu" => { "foo" => { "bar" => "it works!" } } } },
-      "include" => { "menu" => "foo", "locale" => "bar" }
-    ))
+      "include" => { "menu" => "foo", "locale" => "bar" },
+    })
   end
 
   def test_variable_traversing
-    text = %( {{car.bmw}} {{car.gm}} {{car.bmw}} )
-
-    expected = %( good bad good )
-    assert_equal(expected, Template.parse(text).render!(@assigns))
+    source = " {{car.bmw}} {{car.gm}} {{car.bmw}} "
+    assert_template_result(" good bad good ", source, @assigns)
   end
 
   def test_variable_piping
@@ -110,10 +104,11 @@ class OutputTest < Minitest::Test
   end
 
   def test_multiple_pipings
+    assigns = { 'best_cars' => 'bmw' }
     text     = %( {{ best_cars | cite_funny | paragraph }} )
     expected = %( <p>LOL: bmw</p> )
 
-    assert_equal(expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter]))
+    assert_equal(expected, Template.parse(text).render!(assigns, filters: [FunnyFilter]))
   end
 
   def test_link_to

test/integration/parsing_quirks_test.rb

@@ -129,6 +129,26 @@ class ParsingQuirksTest < Minitest::Test
   end
 
   def test_contains_in_id
-    assert_template_result(' YES ', '{% if containsallshipments == true %} YES {% endif %}', 'containsallshipments' => true)
+    assert_template_result(' YES ', '{% if containsallshipments == true %} YES {% endif %}', { 'containsallshipments' => true })
+  end
+
+  def test_incomplete_expression
+    with_error_mode(:lax) do
+      assert_template_result("false", "{{ false - }}")
+      assert_template_result("false", "{{ false > }}")
+      assert_template_result("false", "{{ false < }}")
+      assert_template_result("false", "{{ false = }}")
+      assert_template_result("false", "{{ false ! }}")
+      assert_template_result("false", "{{ false 1 }}")
+      assert_template_result("false", "{{ false a }}")
+
+      assert_template_result("false", "{% liquid assign foo = false -\n%}{{ foo }}")
+      assert_template_result("false", "{% liquid assign foo = false >\n%}{{ foo }}")
+      assert_template_result("false", "{% liquid assign foo = false <\n%}{{ foo }}")
+      assert_template_result("false", "{% liquid assign foo = false =\n%}{{ foo }}")
+      assert_template_result("false", "{% liquid assign foo = false !\n%}{{ foo }}")
+      assert_template_result("false", "{% liquid assign foo = false 1\n%}{{ foo }}")
+      assert_template_result("false", "{% liquid assign foo = false a\n%}{{ foo }}")
+    end
   end
 end # ParsingQuirksTest

test/integration/profiler_test.rb

@@ -3,6 +3,27 @@
 require 'test_helper'
 
 class ProfilerTest < Minitest::Test
+  class TestDrop < Liquid::Drop
+    def initialize(value)
+      super()
+      @value = value
+    end
+
+    def to_s
+      artificial_execution_time
+
+      @value
+    end
+
+    private
+
+    # Monotonic clock precision fluctuate based on the operating system
+    # By introducing a small sleep we ensure ourselves to register a non zero unit of time
+    def artificial_execution_time
+      sleep(Process.clock_getres(Process::CLOCK_MONOTONIC))
+    end
+  end
+
   include Liquid
 
   class ProfilingFileSystem
@@ -12,7 +33,7 @@ class ProfilerTest < Minitest::Test
   end
 
   def setup
-    Liquid::Template.file_system = ProfilingFileSystem.new
+    Liquid::Environment.default.file_system = ProfilingFileSystem.new
   end
 
   def test_template_allows_flagging_profiling
@@ -198,16 +219,22 @@ class ProfilerTest < Minitest::Test
 
   def test_profiling_supports_self_time
     t = Template.parse("{% for item in collection %} {{ item }} {% endfor %}", profile: true)
-    t.render!("collection" => ["one", "two"])
-    leaf = t.profiler[0].children[0]
+    collection = [
+      TestDrop.new("one"),
+      TestDrop.new("two"),
+    ]
+    output = t.render!("collection" => collection)
+    assert_equal(" one  two ", output)
 
-    assert_operator(leaf.self_time, :>, 0)
+    leaf = t.profiler[0].children[0]
+    assert_operator(leaf.self_time, :>, 0.0)
   end
 
   def test_profiling_supports_total_time
-    t = Template.parse("{% if true %} {% increment test %} {{ test }} {% endif %}", profile: true)
-    t.render!
+    t = Template.parse("{% if true %} {{ test }} {% endif %}", profile: true)
+    output = t.render!("test" => TestDrop.new("one"))
+    assert_equal(" one ", output)
 
-    assert_operator(t.profiler[0].total_time, :>, 0)
+    assert_operator(t.profiler[0].total_time, :>, 0.0)
   end
 end

test/integration/standard_filter_test.rb

@@ -3,10 +3,6 @@
 
 require 'test_helper'
 
-class Filters
-  include Liquid::StandardFilters
-end
-
 class TestThing
   attr_reader :foo
 
@@ -29,8 +25,24 @@ class TestThing
 end
 
 class TestDrop < Liquid::Drop
-  def test
-    "testfoo"
+  def initialize(value:)
+    @value = value
+  end
+
+  attr_reader :value
+
+  def registers
+    "{#{@value.inspect}=>#{@context.registers[@value].inspect}}"
+  end
+end
+
+class TestModel
+  def initialize(value:)
+    @value = value
+  end
+
+  def to_liquid
+    TestDrop.new(value: @value)
   end
 end
 
@@ -53,10 +65,13 @@ class NumberLikeThing < Liquid::Drop
 end
 
 class StandardFiltersTest < Minitest::Test
+  Filters = Class.new(Liquid::StrainerTemplate)
+  Filters.add_filter(Liquid::StandardFilters)
+
   include Liquid
 
   def setup
-    @filters = Filters.new
+    @filters = Filters.new(Context.new)
   end
 
   def test_size
@@ -94,6 +109,10 @@ class StandardFiltersTest < Minitest::Test
     assert_raises(Liquid::ArgumentError) do
       @filters.slice('foobar', 0, "")
     end
+    assert_equal("", @filters.slice("foobar", 0, -(1 << 64)))
+    assert_equal("foobar", @filters.slice("foobar", 0, 1 << 63))
+    assert_equal("", @filters.slice("foobar", 1 << 63, 6))
+    assert_equal("", @filters.slice("foobar", -(1 << 63), 6))
   end
 
   def test_slice_on_arrays
@@ -108,6 +127,10 @@ class StandardFiltersTest < Minitest::Test
     assert_equal(%w(r), @filters.slice(input, -1))
     assert_equal(%w(), @filters.slice(input, 100, 10))
     assert_equal(%w(), @filters.slice(input, -100, 10))
+    assert_equal([], @filters.slice(input, 0, -(1 << 64)))
+    assert_equal(input, @filters.slice(input, 0, 1 << 63))
+    assert_equal([], @filters.slice(input, 1 << 63, 6))
+    assert_equal([], @filters.slice(input, -(1 << 63), 6))
   end
 
   def test_truncate
@@ -117,6 +140,8 @@ class StandardFiltersTest < Minitest::Test
     assert_equal('1234567890', @filters.truncate('1234567890'))
     assert_equal("测试...", @filters.truncate("测试测试测试测试", 5))
     assert_equal('12341', @filters.truncate("1234567890", 5, 1))
+    assert_equal("foobar", @filters.truncate("foobar", 1 << 63))
+    assert_equal("...", @filters.truncate("foobar", -(1 << 63)))
   end
 
   def test_split
@@ -145,6 +170,61 @@ class StandardFiltersTest < Minitest::Test
     assert_equal('&lt;strong&gt;Hulk&lt;/strong&gt;', @filters.escape_once('&lt;strong&gt;Hulk</strong>'))
   end
 
+  def test_base64_encode
+    assert_equal('b25lIHR3byB0aHJlZQ==', @filters.base64_encode('one two three'))
+    assert_equal('', @filters.base64_encode(nil))
+  end
+
+  def test_base64_decode
+    decoded = @filters.base64_decode('b25lIHR3byB0aHJlZQ==')
+    assert_equal('one two three', decoded)
+    assert_equal(Encoding::UTF_8, decoded.encoding)
+
+    decoded = @filters.base64_decode('4pyF')
+    assert_equal('✅', decoded)
+    assert_equal(Encoding::UTF_8, decoded.encoding)
+
+    decoded = @filters.base64_decode("/w==")
+    assert_equal(Encoding::ASCII_8BIT, decoded.encoding)
+    assert_equal((+"\xFF").force_encoding(Encoding::ASCII_8BIT), decoded)
+
+    exception = assert_raises(Liquid::ArgumentError) do
+      @filters.base64_decode("invalidbase64")
+    end
+
+    assert_equal('Liquid error: invalid base64 provided to base64_decode', exception.message)
+  end
+
+  def test_base64_url_safe_encode
+    assert_equal(
+      'YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXogQUJDREVGR0hJSktMTU5PUFFSU1RVVldYWVogMTIzNDU2Nzg5MCAhQCMkJV4mKigpLT1fKy8_Ljo7W117fVx8',
+      @filters.base64_url_safe_encode('abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ 1234567890 !@#$%^&*()-=_+/?.:;[]{}\|'),
+    )
+    assert_equal('', @filters.base64_url_safe_encode(nil))
+  end
+
+  def test_base64_url_safe_decode
+    decoded = @filters.base64_url_safe_decode('YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXogQUJDREVGR0hJSktMTU5PUFFSU1RVVldYWVogMTIzNDU2Nzg5MCAhQCMkJV4mKigpLT1fKy8_Ljo7W117fVx8')
+    assert_equal(
+      'abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ 1234567890 !@#$%^&*()-=_+/?.:;[]{}\|',
+      decoded,
+    )
+    assert_equal(Encoding::UTF_8, decoded.encoding)
+
+    decoded = @filters.base64_url_safe_decode('4pyF')
+    assert_equal('✅', decoded)
+    assert_equal(Encoding::UTF_8, decoded.encoding)
+
+    decoded = @filters.base64_url_safe_decode("_w==")
+    assert_equal(Encoding::ASCII_8BIT, decoded.encoding)
+    assert_equal((+"\xFF").force_encoding(Encoding::ASCII_8BIT), decoded)
+
+    exception = assert_raises(Liquid::ArgumentError) do
+      @filters.base64_url_safe_decode("invalidbase64")
+    end
+    assert_equal('Liquid error: invalid base64 provided to base64_url_safe_decode', exception.message)
+  end
+
   def test_url_encode
     assert_equal('foo%2B1%40example.com', @filters.url_encode('[email protected]'))
     assert_equal('1', @filters.url_encode(1))
@@ -171,10 +251,15 @@ class StandardFiltersTest < Minitest::Test
     assert_equal('one two three', @filters.truncatewords('one two three'))
     assert_equal(
       'Two small (13&#8221; x 5.5&#8221; x 10&#8221; high) baskets fit inside one large basket (13&#8221;...',
-        @filters.truncatewords('Two small (13&#8221; x 5.5&#8221; x 10&#8221; high) baskets fit inside one large basket (13&#8221; x 16&#8221; x 10.5&#8221; high) with cover.', 15)
+      @filters.truncatewords('Two small (13&#8221; x 5.5&#8221; x 10&#8221; high) baskets fit inside one large basket (13&#8221; x 16&#8221; x 10.5&#8221; high) with cover.', 15),
     )
     assert_equal("测试测试测试测试", @filters.truncatewords('测试测试测试测试', 5))
     assert_equal('one two1', @filters.truncatewords("one two three", 2, 1))
+    assert_equal('one two three...', @filters.truncatewords("one  two\tthree\nfour", 3))
+    assert_equal('one two...', @filters.truncatewords("one two three four", 2))
+    assert_equal('one...', @filters.truncatewords("one two three four", 0))
+    assert_equal('one two three four', @filters.truncatewords("one two three four", 1 << 31))
+    assert_equal('one...', @filters.truncatewords("one two three four", -(1 << 32)))
   end
 
   def test_strip_html
@@ -218,8 +303,8 @@ class StandardFiltersTest < Minitest::Test
       { "price" => 1, "handle" => "gamma" },
       { "price" => 2, "handle" => "epsilon" },
       { "price" => 4, "handle" => "alpha" },
-      { "handle" => "delta" },
       { "handle" => "beta" },
+      { "handle" => "delta" },
     ]
     assert_equal(expectation, @filters.sort(input, "price"))
   end
@@ -246,8 +331,8 @@ class StandardFiltersTest < Minitest::Test
       { "price" => "1", "handle" => "gamma" },
       { "price" => 2, "handle" => "epsilon" },
       { "price" => "4", "handle" => "alpha" },
-      { "handle" => "delta" },
       { "handle" => "beta" },
+      { "handle" => "delta" },
     ]
     assert_equal(expectation, @filters.sort_natural(input, "price"))
   end
@@ -322,8 +407,9 @@ class StandardFiltersTest < Minitest::Test
     assert_equal(["foo"], @filters.uniq("foo"))
     assert_equal([1, 3, 2, 4], @filters.uniq([1, 1, 3, 2, 3, 1, 4, 3, 2, 1]))
     assert_equal([{ "a" => 1 }, { "a" => 3 }, { "a" => 2 }], @filters.uniq([{ "a" => 1 }, { "a" => 3 }, { "a" => 1 }, { "a" => 2 }], "a"))
-    testdrop = TestDrop.new
-    assert_equal([testdrop], @filters.uniq([testdrop, TestDrop.new], 'test'))
+    test_drop = TestDrop.new(value: "test")
+    test_drop_alternate = TestDrop.new(value: "test")
+    assert_equal([test_drop], @filters.uniq([test_drop, test_drop_alternate], 'value'))
   end
 
   def test_uniq_empty_array
@@ -368,8 +454,11 @@ class StandardFiltersTest < Minitest::Test
 
   def test_map
     assert_equal([1, 2, 3, 4], @filters.map([{ "a" => 1 }, { "a" => 2 }, { "a" => 3 }, { "a" => 4 }], 'a'))
-    assert_template_result('abc', "{{ ary | map:'foo' | map:'bar' }}",
-      'ary' => [{ 'foo' => { 'bar' => 'a' } }, { 'foo' => { 'bar' => 'b' } }, { 'foo' => { 'bar' => 'c' } }])
+    assert_template_result(
+      'abc',
+      "{{ ary | map:'foo' | map:'bar' }}",
+      { 'ary' => [{ 'foo' => { 'bar' => 'a' } }, { 'foo' => { 'bar' => 'b' } }, { 'foo' => { 'bar' => 'c' } }] },
+    )
   end
 
   def test_map_doesnt_call_arbitrary_stuff
@@ -379,18 +468,31 @@ class StandardFiltersTest < Minitest::Test
 
   def test_map_calls_to_liquid
     t = TestThing.new
-    assert_template_result("woot: 1", '{{ foo | map: "whatever" }}', "foo" => [t])
+    assert_template_result("woot: 1", '{{ foo | map: "whatever" }}', { "foo" => [t] })
+  end
+
+  def test_map_calls_context=
+    model = TestModel.new(value: :test)
+
+    template = Template.parse('{{ foo | map: "registers" }}')
+    template.registers[:test] = 1234
+    template.assigns['foo'] = [model]
+
+    assert_template_result("{:test=>1234}", template.render!)
   end
 
   def test_map_on_hashes
-    assert_template_result("4217", '{{ thing | map: "foo" | map: "bar" }}',
-      "thing" => { "foo" => [{ "bar" => 42 }, { "bar" => 17 }] })
+    assert_template_result(
+      "4217",
+      '{{ thing | map: "foo" | map: "bar" }}',
+      { "thing" => { "foo" => [{ "bar" => 42 }, { "bar" => 17 }] } },
+    )
   end
 
   def test_legacy_map_on_hashes_with_dynamic_key
     template = "{% assign key = 'foo' %}{{ thing | map: key | map: 'bar' }}"
     hash     = { "foo" => { "bar" => 42 } }
-    assert_template_result("42", template, "thing" => hash)
+    assert_template_result("42", template, { "thing" => hash })
   end
 
   def test_sort_calls_to_liquid
@@ -400,10 +502,10 @@ class StandardFiltersTest < Minitest::Test
   end
 
   def test_map_over_proc
-    drop  = TestDrop.new
+    drop  = TestDrop.new(value: "testfoo")
     p     = proc { drop }
-    templ = '{{ procs | map: "test" }}'
-    assert_template_result("testfoo", templ, "procs" => [p])
+    output = Liquid::Template.parse('{{ procs | map: "value" }}').render!({ "procs" => [p] })
+    assert_equal("testfoo", output)
   end
 
   def test_map_over_drops_returning_procs
@@ -415,12 +517,13 @@ class StandardFiltersTest < Minitest::Test
         "proc" => -> { "bar" },
       },
     ]
-    templ = '{{ drops | map: "proc" }}'
-    assert_template_result("foobar", templ, "drops" => drops)
+    output = Liquid::Template.parse('{{ drops | map: "proc" }}').render!({ "drops" => drops })
+    assert_equal("foobar", output)
   end
 
   def test_map_works_on_enumerables
-    assert_template_result("123", '{{ foo | map: "foo" }}', "foo" => TestEnumerable.new)
+    output = Liquid::Template.parse('{{ foo | map: "foo" }}').render!({ "foo" => TestEnumerable.new })
+    assert_equal("123", output)
   end
 
   def test_map_returns_empty_on_2d_input_array
@@ -447,16 +550,16 @@ class StandardFiltersTest < Minitest::Test
   end
 
   def test_sort_works_on_enumerables
-    assert_template_result("213", '{{ foo | sort: "bar" | map: "foo" }}', "foo" => TestEnumerable.new)
+    assert_template_result("213", '{{ foo | sort: "bar" | map: "foo" }}', { "foo" => TestEnumerable.new })
   end
 
   def test_first_and_last_call_to_liquid
-    assert_template_result('foobar', '{{ foo | first }}', 'foo' => [ThingWithToLiquid.new])
-    assert_template_result('foobar', '{{ foo | last }}', 'foo' => [ThingWithToLiquid.new])
+    assert_template_result('foobar', '{{ foo | first }}', { 'foo' => [ThingWithToLiquid.new] })
+    assert_template_result('foobar', '{{ foo | last }}', { 'foo' => [ThingWithToLiquid.new] })
   end
 
   def test_truncate_calls_to_liquid
-    assert_template_result("wo...", '{{ foo | truncate: 5 }}', "foo" => TestThing.new)
+    assert_template_result("wo...", '{{ foo | truncate: 5 }}', { "foo" => TestThing.new })
   end
 
   def test_date
@@ -498,19 +601,31 @@ class StandardFiltersTest < Minitest::Test
   end
 
   def test_replace
-    assert_equal('2 2 2 2', @filters.replace('1 1 1 1', '1', 2))
+    assert_equal('b b b b', @filters.replace('a a a a', 'a', 'b'))
     assert_equal('2 2 2 2', @filters.replace('1 1 1 1', 1, 2))
-    assert_equal('2 1 1 1', @filters.replace_first('1 1 1 1', '1', 2))
+    assert_equal('1 1 1 1', @filters.replace('1 1 1 1', 2, 3))
+    assert_template_result('2 2 2 2', "{{ '1 1 1 1' | replace: '1', 2 }}")
+
+    assert_equal('b a a a', @filters.replace_first('a a a a', 'a', 'b'))
     assert_equal('2 1 1 1', @filters.replace_first('1 1 1 1', 1, 2))
+    assert_equal('1 1 1 1', @filters.replace_first('1 1 1 1', 2, 3))
     assert_template_result('2 1 1 1', "{{ '1 1 1 1' | replace_first: '1', 2 }}")
+
+    assert_equal('a a a b', @filters.replace_last('a a a a', 'a', 'b'))
+    assert_equal('1 1 1 2', @filters.replace_last('1 1 1 1', 1, 2))
+    assert_equal('1 1 1 1', @filters.replace_last('1 1 1 1', 2, 3))
+    assert_template_result('1 1 1 2', "{{ '1 1 1 1' | replace_last: '1', 2 }}")
   end
 
   def test_remove
     assert_equal('   ', @filters.remove("a a a a", 'a'))
-    assert_equal('   ', @filters.remove("1 1 1 1", 1))
-    assert_equal('a a a', @filters.remove_first("a a a a", 'a '))
-    assert_equal(' 1 1 1', @filters.remove_first("1 1 1 1", 1))
-    assert_template_result('a a a', "{{ 'a a a a' | remove_first: 'a ' }}")
+    assert_template_result('   ', "{{ '1 1 1 1' | remove: 1 }}")
+
+    assert_equal('b a a', @filters.remove_first("a b a a", 'a '))
+    assert_template_result(' 1 1 1', "{{ '1 1 1 1' | remove_first: 1 }}")
+
+    assert_equal('a a b', @filters.remove_last("a a b a", ' a'))
+    assert_template_result('1 1 1 ', "{{ '1 1 1 1' | remove_last: 1 }}")
   end
 
   def test_pipes_in_string_arguments
@@ -518,41 +633,42 @@ class StandardFiltersTest < Minitest::Test
   end
 
   def test_strip
-    assert_template_result('ab c', "{{ source | strip }}", 'source' => " ab c  ")
-    assert_template_result('ab c', "{{ source | strip }}", 'source' => " \tab c  \n \t")
+    assert_template_result('ab c', "{{ source | strip }}", { 'source' => " ab c  " })
+    assert_template_result('ab c', "{{ source | strip }}", { 'source' => " \tab c  \n \t" })
   end
 
   def test_lstrip
-    assert_template_result('ab c  ', "{{ source | lstrip }}", 'source' => " ab c  ")
-    assert_template_result("ab c  \n \t", "{{ source | lstrip }}", 'source' => " \tab c  \n \t")
+    assert_template_result('ab c  ', "{{ source | lstrip }}", { 'source' => " ab c  " })
+    assert_template_result("ab c  \n \t", "{{ source | lstrip }}", { 'source' => " \tab c  \n \t" })
   end
 
   def test_rstrip
-    assert_template_result(" ab c", "{{ source | rstrip }}", 'source' => " ab c  ")
-    assert_template_result(" \tab c", "{{ source | rstrip }}", 'source' => " \tab c  \n \t")
+    assert_template_result(" ab c", "{{ source | rstrip }}", { 'source' => " ab c  " })
+    assert_template_result(" \tab c", "{{ source | rstrip }}", { 'source' => " \tab c  \n \t" })
   end
 
   def test_strip_newlines
-    assert_template_result('abc', "{{ source | strip_newlines }}", 'source' => "a\nb\nc")
-    assert_template_result('abc', "{{ source | strip_newlines }}", 'source' => "a\r\nb\nc")
+    assert_template_result('abc', "{{ source | strip_newlines }}", { 'source' => "a\nb\nc" })
+    assert_template_result('abc', "{{ source | strip_newlines }}", { 'source' => "a\r\nb\nc" })
   end
 
   def test_newlines_to_br
-    assert_template_result("a<br />\nb<br />\nc", "{{ source | newline_to_br }}", 'source' => "a\nb\nc")
+    assert_template_result("a<br />\nb<br />\nc", "{{ source | newline_to_br }}", { 'source' => "a\nb\nc" })
+    assert_template_result("a<br />\nb<br />\nc", "{{ source | newline_to_br }}", { 'source' => "a\r\nb\nc" })
   end
 
   def test_plus
     assert_template_result("2", "{{ 1 | plus:1 }}")
     assert_template_result("2.0", "{{ '1' | plus:'1.0' }}")
 
-    assert_template_result("5", "{{ price | plus:'2' }}", 'price' => NumberLikeThing.new(3))
+    assert_template_result("5", "{{ price | plus:'2' }}", { 'price' => NumberLikeThing.new(3) })
   end
 
   def test_minus
-    assert_template_result("4", "{{ input | minus:operand }}", 'input' => 5, 'operand' => 1)
+    assert_template_result("4", "{{ input | minus:operand }}", { 'input' => 5, 'operand' => 1 })
     assert_template_result("2.3", "{{ '4.3' | minus:'2' }}")
 
-    assert_template_result("5", "{{ price | minus:'2' }}", 'price' => NumberLikeThing.new(7))
+    assert_template_result("5", "{{ price | minus:'2' }}", { 'price' => NumberLikeThing.new(7) })
   end
 
   def test_abs
@@ -575,7 +691,7 @@ class StandardFiltersTest < Minitest::Test
     assert_template_result("7.25", "{{ 0.0725 | times:100 }}")
     assert_template_result("-7.25", '{{ "-0.0725" | times:100 }}')
     assert_template_result("7.25", '{{ "-0.0725" | times: -100 }}')
-    assert_template_result("4", "{{ price | times:2 }}", 'price' => NumberLikeThing.new(2))
+    assert_template_result("4", "{{ price | times:2 }}", { 'price' => NumberLikeThing.new(2) })
   end
 
   def test_divided_by
@@ -590,7 +706,7 @@ class StandardFiltersTest < Minitest::Test
       assert_template_result("4", "{{ 1 | modulo: 0 }}")
     end
 
-    assert_template_result("5", "{{ price | divided_by:2 }}", 'price' => NumberLikeThing.new(10))
+    assert_template_result("5", "{{ price | divided_by:2 }}", { 'price' => NumberLikeThing.new(10) })
   end
 
   def test_modulo
@@ -599,39 +715,39 @@ class StandardFiltersTest < Minitest::Test
       assert_template_result("4", "{{ 1 | modulo: 0 }}")
     end
 
-    assert_template_result("1", "{{ price | modulo:2 }}", 'price' => NumberLikeThing.new(3))
+    assert_template_result("1", "{{ price | modulo:2 }}", { 'price' => NumberLikeThing.new(3) })
   end
 
   def test_round
-    assert_template_result("5", "{{ input | round }}", 'input' => 4.6)
+    assert_template_result("5", "{{ input | round }}", { 'input' => 4.6 })
     assert_template_result("4", "{{ '4.3' | round }}")
-    assert_template_result("4.56", "{{ input | round: 2 }}", 'input' => 4.5612)
+    assert_template_result("4.56", "{{ input | round: 2 }}", { 'input' => 4.5612 })
     assert_raises(Liquid::FloatDomainError) do
       assert_template_result("4", "{{ 1.0 | divided_by: 0.0 | round }}")
     end
 
-    assert_template_result("5", "{{ price | round }}", 'price' => NumberLikeThing.new(4.6))
-    assert_template_result("4", "{{ price | round }}", 'price' => NumberLikeThing.new(4.3))
+    assert_template_result("5", "{{ price | round }}", { 'price' => NumberLikeThing.new(4.6) })
+    assert_template_result("4", "{{ price | round }}", { 'price' => NumberLikeThing.new(4.3) })
   end
 
   def test_ceil
-    assert_template_result("5", "{{ input | ceil }}", 'input' => 4.6)
+    assert_template_result("5", "{{ input | ceil }}", { 'input' => 4.6 })
     assert_template_result("5", "{{ '4.3' | ceil }}")
     assert_raises(Liquid::FloatDomainError) do
       assert_template_result("4", "{{ 1.0 | divided_by: 0.0 | ceil }}")
     end
 
-    assert_template_result("5", "{{ price | ceil }}", 'price' => NumberLikeThing.new(4.6))
+    assert_template_result("5", "{{ price | ceil }}", { 'price' => NumberLikeThing.new(4.6) })
   end
 
   def test_floor
-    assert_template_result("4", "{{ input | floor }}", 'input' => 4.6)
+    assert_template_result("4", "{{ input | floor }}", { 'input' => 4.6 })
     assert_template_result("4", "{{ '4.3' | floor }}")
     assert_raises(Liquid::FloatDomainError) do
       assert_template_result("4", "{{ 1.0 | divided_by: 0.0 | floor }}")
     end
 
-    assert_template_result("5", "{{ price | floor }}", 'price' => NumberLikeThing.new(5.4))
+    assert_template_result("5", "{{ price | floor }}", { 'price' => NumberLikeThing.new(5.4) })
   end
 
   def test_at_most
@@ -640,9 +756,9 @@ class StandardFiltersTest < Minitest::Test
     assert_template_result("5", "{{ 5 | at_most:6 }}")
 
     assert_template_result("4.5", "{{ 4.5 | at_most:5 }}")
-    assert_template_result("5", "{{ width | at_most:5 }}", 'width' => NumberLikeThing.new(6))
-    assert_template_result("4", "{{ width | at_most:5 }}", 'width' => NumberLikeThing.new(4))
-    assert_template_result("4", "{{ 5 | at_most: width }}", 'width' => NumberLikeThing.new(4))
+    assert_template_result("5", "{{ width | at_most:5 }}", { 'width' => NumberLikeThing.new(6) })
+    assert_template_result("4", "{{ width | at_most:5 }}", { 'width' => NumberLikeThing.new(4) })
+    assert_template_result("4", "{{ 5 | at_most: width }}", { 'width' => NumberLikeThing.new(4) })
   end
 
   def test_at_least
@@ -651,9 +767,9 @@ class StandardFiltersTest < Minitest::Test
     assert_template_result("6", "{{ 5 | at_least:6 }}")
 
     assert_template_result("5", "{{ 4.5 | at_least:5 }}")
-    assert_template_result("6", "{{ width | at_least:5 }}", 'width' => NumberLikeThing.new(6))
-    assert_template_result("5", "{{ width | at_least:5 }}", 'width' => NumberLikeThing.new(4))
-    assert_template_result("6", "{{ 5 | at_least: width }}", 'width' => NumberLikeThing.new(6))
+    assert_template_result("6", "{{ width | at_least:5 }}", { 'width' => NumberLikeThing.new(6) })
+    assert_template_result("5", "{{ width | at_least:5 }}", { 'width' => NumberLikeThing.new(4) })
+    assert_template_result("6", "{{ 5 | at_least: width }}", { 'width' => NumberLikeThing.new(6) })
   end
 
   def test_append
@@ -686,6 +802,8 @@ class StandardFiltersTest < Minitest::Test
     assert_equal("bar", @filters.default([], "bar"))
     assert_equal("bar", @filters.default({}, "bar"))
     assert_template_result('bar', "{{ false | default: 'bar' }}")
+    assert_template_result('bar', "{{ drop | default: 'bar' }}", { 'drop' => BooleanDrop.new(false) })
+    assert_template_result('Yay', "{{ drop | default: 'bar' }}", { 'drop' => BooleanDrop.new(true) })
   end
 
   def test_default_handle_false
@@ -696,6 +814,8 @@ class StandardFiltersTest < Minitest::Test
     assert_equal("bar", @filters.default([], "bar", "allow_false" => true))
     assert_equal("bar", @filters.default({}, "bar", "allow_false" => true))
     assert_template_result('false', "{{ false | default: 'bar', allow_false: true }}")
+    assert_template_result('Nay', "{{ drop | default: 'bar', allow_false: true }}", { 'drop' => BooleanDrop.new(false) })
+    assert_template_result('Yay', "{{ drop | default: 'bar', allow_false: true }}", { 'drop' => BooleanDrop.new(true) })
   end
 
   def test_cannot_access_private_methods
@@ -724,6 +844,18 @@ class StandardFiltersTest < Minitest::Test
     assert_equal(expectation, @filters.where(input, "ok"))
   end
 
+  def test_where_string_keys
+    input = [
+      "alpha", "beta", "gamma", "delta"
+    ]
+
+    expectation = [
+      "beta",
+    ]
+
+    assert_equal(expectation, @filters.where(input, "be"))
+  end
+
   def test_where_no_key_set
     input = [
       { "handle" => "alpha", "ok" => true },
@@ -769,7 +901,7 @@ class StandardFiltersTest < Minitest::Test
   end
 
   def test_all_filters_never_raise_non_liquid_exception
-    test_drop = TestDrop.new
+    test_drop = TestDrop.new(value: "test")
     test_drop.context = Context.new
     test_enum = TestEnumerable.new
     test_enum.context = Context.new
@@ -794,19 +926,14 @@ class StandardFiltersTest < Minitest::Test
       { 1 => "bar" },
       ["foo", 123, nil, true, false, Drop, ["foo"], { foo: "bar" }],
     ]
-    test_types.each do |first|
-      test_types.each do |other|
-        (@filters.methods - Object.methods).each do |method|
-          arg_count = @filters.method(method).arity
-          arg_count *= -1 if arg_count < 0
-          inputs = [first]
-          inputs << ([other] * (arg_count - 1)) if arg_count > 1
-          begin
-            @filters.send(method, *inputs)
-          rescue Liquid::ArgumentError, Liquid::ZeroDivisionError
-            nil
-          end
-        end
+    StandardFilters.public_instance_methods(false).each do |method|
+      arg_count = @filters.method(method).arity
+      arg_count *= -1 if arg_count < 0
+
+      test_types.repeated_permutation(arg_count) do |args|
+        @filters.send(method, *args)
+      rescue Liquid::Error
+        nil
       end
     end
   end
@@ -822,6 +949,108 @@ class StandardFiltersTest < Minitest::Test
     assert_equal([{ "foo" => true }, { "foo" => "for sure" }], @filters.where(input, "foo"))
   end
 
+  def test_sum_with_all_numbers
+    input = [1, 2]
+
+    assert_equal(3, @filters.sum(input))
+    assert_raises(Liquid::ArgumentError, "cannot select the property 'quantity'") do
+      @filters.sum(input, "quantity")
+    end
+  end
+
+  def test_sum_with_numeric_strings
+    input = [1, 2, "3", "4"]
+
+    assert_equal(10, @filters.sum(input))
+    assert_raises(Liquid::ArgumentError, "cannot select the property 'quantity'") do
+      @filters.sum(input, "quantity")
+    end
+  end
+
+  def test_sum_with_nested_arrays
+    input = [1, [2, [3, 4]]]
+
+    assert_equal(10, @filters.sum(input))
+    assert_raises(Liquid::ArgumentError, "cannot select the property 'quantity'") do
+      @filters.sum(input, "quantity")
+    end
+  end
+
+  def test_sum_with_indexable_map_values
+    input = [{ "quantity" => 1 }, { "quantity" => 2, "weight" => 3 }, { "weight" => 4 }]
+
+    assert_equal(0, @filters.sum(input))
+    assert_equal(3, @filters.sum(input, "quantity"))
+    assert_equal(7, @filters.sum(input, "weight"))
+    assert_equal(0, @filters.sum(input, "subtotal"))
+  end
+
+  def test_sum_with_indexable_non_map_values
+    input = [1, [2], "foo", { "quantity" => 3 }]
+
+    assert_equal(3, @filters.sum(input))
+    assert_raises(Liquid::ArgumentError, "cannot select the property 'quantity'") do
+      @filters.sum(input, "quantity")
+    end
+  end
+
+  def test_sum_with_unindexable_values
+    input = [1, true, nil, { "quantity" => 2 }]
+
+    assert_equal(1, @filters.sum(input))
+    assert_raises(Liquid::ArgumentError, "cannot select the property 'quantity'") do
+      @filters.sum(input, "quantity")
+    end
+  end
+
+  def test_sum_without_property_calls_to_liquid
+    t = TestThing.new
+    Liquid::Template.parse('{{ foo | sum }}').render("foo" => [t])
+    assert(t.foo > 0)
+  end
+
+  def test_sum_with_property_calls_to_liquid_on_property_values
+    t = TestThing.new
+    Liquid::Template.parse('{{ foo | sum: "quantity" }}').render("foo" => [{ "quantity" => t }])
+    assert(t.foo > 0)
+  end
+
+  def test_sum_of_floats
+    input = [0.1, 0.2, 0.3]
+    assert_equal(0.6, @filters.sum(input))
+    assert_template_result("0.6", "{{ input | sum }}", { "input" => input })
+  end
+
+  def test_sum_of_negative_floats
+    input = [0.1, 0.2, -0.3]
+    assert_equal(0.0, @filters.sum(input))
+    assert_template_result("0.0", "{{ input | sum }}", { "input" => input })
+  end
+
+  def test_sum_with_float_strings
+    input = [0.1, "0.2", "0.3"]
+    assert_equal(0.6, @filters.sum(input))
+    assert_template_result("0.6", "{{ input | sum }}", { "input" => input })
+  end
+
+  def test_sum_resulting_in_negative_float
+    input = [0.1, -0.2, -0.3]
+    assert_equal(-0.4, @filters.sum(input))
+    assert_template_result("-0.4", "{{ input | sum }}", { "input" => input })
+  end
+
+  def test_sum_with_floats_and_indexable_map_values
+    input = [{ "quantity" => 1 }, { "quantity" => 0.2, "weight" => -0.3 }, { "weight" => 0.4 }]
+    assert_equal(0.0, @filters.sum(input))
+    assert_equal(1.2, @filters.sum(input, "quantity"))
+    assert_equal(0.1, @filters.sum(input, "weight"))
+    assert_equal(0.0, @filters.sum(input, "subtotal"))
+    assert_template_result("0", "{{ input | sum }}", { "input" => input })
+    assert_template_result("1.2", "{{ input | sum: 'quantity' }}", { "input" => input })
+    assert_template_result("0.1", "{{ input | sum: 'weight' }}", { "input" => input })
+    assert_template_result("0", "{{ input | sum: 'subtotal' }}", { "input" => input })
+  end
+
   private
 
   def with_timezone(tz)

test/integration/tags/break_tag_test.rb

@@ -9,8 +9,8 @@ class BreakTagTest < Minitest::Test
   # block
   def test_break_with_no_block
     assigns  = { 'i' => 1 }
-    markup   = '{% break %}'
-    expected = ''
+    markup   = 'before{% break %}after'
+    expected = 'before'
 
     assert_template_result(expected, markup, assigns)
   end

test/integration/tags/cycle_tag_test.rb

@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class CycleTagTest < Minitest::Test
+  def test_simple_cycle
+    template = <<~LIQUID
+      {%- cycle '1', '2', '3' -%}
+      {%- cycle '1', '2', '3' -%}
+      {%- cycle '1', '2', '3' -%}
+    LIQUID
+
+    assert_template_result("123", template)
+  end
+
+  def test_simple_cycle_inside_for_loop
+    template = <<~LIQUID
+      {%- for i in (1..3) -%}
+        {% cycle '1', '2', '3' %}
+      {%- endfor -%}
+    LIQUID
+
+    assert_template_result("123", template)
+  end
+
+  def test_cycle_with_variables_inside_for_loop
+    template = <<~LIQUID
+      {%- assign a = 1 -%}
+      {%- assign b = 2 -%}
+      {%- assign c = 3 -%}
+      {%- for i in (1..3) -%}
+        {% cycle a, b, c %}
+      {%- endfor -%}
+    LIQUID
+
+    assert_template_result("123", template)
+  end
+
+  def test_cycle_tag_always_resets_cycle
+    template = <<~LIQUID
+      {%- assign a = "1" -%}
+      {%- cycle a, "2" -%}
+      {%- cycle a, "2" -%}
+    LIQUID
+
+    assert_template_result("11", template)
+  end
+end

test/integration/tags/echo_test.rb

@@ -6,7 +6,7 @@ class EchoTest < Minitest::Test
   include Liquid
 
   def test_echo_outputs_its_input
-    assert_template_result('BAR', <<~LIQUID, 'variable-name' => 'bar')
+    assert_template_result('BAR', <<~LIQUID, { 'variable-name' => 'bar' })
       {%- echo variable-name | upcase -%}
     LIQUID
   end

test/integration/tags/for_tag_test.rb

@@ -12,10 +12,10 @@ class ForTagTest < Minitest::Test
   include Liquid
 
   def test_for
-    assert_template_result(' yo  yo  yo  yo ', '{%for item in array%} yo {%endfor%}', 'array' => [1, 2, 3, 4])
-    assert_template_result('yoyo', '{%for item in array%}yo{%endfor%}', 'array' => [1, 2])
-    assert_template_result(' yo ', '{%for item in array%} yo {%endfor%}', 'array' => [1])
-    assert_template_result('', '{%for item in array%}{%endfor%}', 'array' => [1, 2])
+    assert_template_result(' yo  yo  yo  yo ', '{%for item in array%} yo {%endfor%}', { 'array' => [1, 2, 3, 4] })
+    assert_template_result('yoyo', '{%for item in array%}yo{%endfor%}', { 'array' => [1, 2] })
+    assert_template_result(' yo ', '{%for item in array%} yo {%endfor%}', { 'array' => [1] })
+    assert_template_result('', '{%for item in array%}{%endfor%}', { 'array' => [1, 2] })
     expected = <<HERE
 
   yo
@@ -30,7 +30,7 @@ HERE
         yo
       {%endfor%}
     HERE
-    assert_template_result(expected, template, 'array' => [1, 2, 3])
+    assert_template_result(expected, template, { 'array' => [1, 2, 3] })
   end
 
   def test_for_reversed
@@ -45,37 +45,39 @@ HERE
       Template.parse('{% for i in (a..2) %}{% endfor %}').render!("a" => [1, 2])
     end
 
-    assert_template_result(' 0  1  2  3 ', '{% for item in (a..3) %} {{item}} {% endfor %}', "a" => "invalid integer")
+    assert_template_result(' 0  1  2  3 ', '{% for item in (a..3) %} {{item}} {% endfor %}', { "a" => "invalid integer" })
   end
 
   def test_for_with_variable_range
-    assert_template_result(' 1  2  3 ', '{%for item in (1..foobar) %} {{item}} {%endfor%}', "foobar" => 3)
+    assert_template_result(' 1  2  3 ', '{%for item in (1..foobar) %} {{item}} {%endfor%}', { "foobar" => 3 })
   end
 
   def test_for_with_hash_value_range
     foobar = { "value" => 3 }
-    assert_template_result(' 1  2  3 ', '{%for item in (1..foobar.value) %} {{item}} {%endfor%}', "foobar" => foobar)
+    assert_template_result(' 1  2  3 ', '{%for item in (1..foobar.value) %} {{item}} {%endfor%}', { "foobar" => foobar })
   end
 
   def test_for_with_drop_value_range
     foobar = ThingWithValue.new
-    assert_template_result(' 1  2  3 ', '{%for item in (1..foobar.value) %} {{item}} {%endfor%}', "foobar" => foobar)
+    assert_template_result(' 1  2  3 ', '{%for item in (1..foobar.value) %} {{item}} {%endfor%}', { "foobar" => foobar })
   end
 
   def test_for_with_variable
-    assert_template_result(' 1  2  3 ', '{%for item in array%} {{item}} {%endfor%}', 'array' => [1, 2, 3])
-    assert_template_result('123', '{%for item in array%}{{item}}{%endfor%}', 'array' => [1, 2, 3])
-    assert_template_result('123', '{% for item in array %}{{item}}{% endfor %}', 'array' => [1, 2, 3])
-    assert_template_result('abcd', '{%for item in array%}{{item}}{%endfor%}', 'array' => ['a', 'b', 'c', 'd'])
-    assert_template_result('a b c', '{%for item in array%}{{item}}{%endfor%}', 'array' => ['a', ' ', 'b', ' ', 'c'])
-    assert_template_result('abc', '{%for item in array%}{{item}}{%endfor%}', 'array' => ['a', '', 'b', '', 'c'])
+    assert_template_result(' 1  2  3 ', '{%for item in array%} {{item}} {%endfor%}', { 'array' => [1, 2, 3] })
+    assert_template_result('123', '{%for item in array%}{{item}}{%endfor%}', { 'array' => [1, 2, 3] })
+    assert_template_result('123', '{% for item in array %}{{item}}{% endfor %}', { 'array' => [1, 2, 3] })
+    assert_template_result('abcd', '{%for item in array%}{{item}}{%endfor%}', { 'array' => ['a', 'b', 'c', 'd'] })
+    assert_template_result('a b c', '{%for item in array%}{{item}}{%endfor%}', { 'array' => ['a', ' ', 'b', ' ', 'c'] })
+    assert_template_result('abc', '{%for item in array%}{{item}}{%endfor%}', { 'array' => ['a', '', 'b', '', 'c'] })
   end
 
   def test_for_helpers
     assigns = { 'array' => [1, 2, 3] }
-    assert_template_result(' 1/3  2/3  3/3 ',
+    assert_template_result(
+      ' 1/3  2/3  3/3 ',
       '{%for item in array%} {{forloop.index}}/{{forloop.length}} {%endfor%}',
-      assigns)
+      assigns,
+    )
     assert_template_result(' 1  2  3 ', '{%for item in array%} {{forloop.index}} {%endfor%}', assigns)
     assert_template_result(' 0  1  2 ', '{%for item in array%} {{forloop.index0}} {%endfor%}', assigns)
     assert_template_result(' 2  1  0 ', '{%for item in array%} {{forloop.rindex0}} {%endfor%}', assigns)
@@ -86,15 +88,17 @@ HERE
 
   def test_for_and_if
     assigns = { 'array' => [1, 2, 3] }
-    assert_template_result('+--',
+    assert_template_result(
+      '+--',
       '{%for item in array%}{% if forloop.first %}+{% else %}-{% endif %}{%endfor%}',
-      assigns)
+      assigns,
+    )
   end
 
   def test_for_else
-    assert_template_result('+++', '{%for item in array%}+{%else%}-{%endfor%}', 'array' => [1, 2, 3])
-    assert_template_result('-',   '{%for item in array%}+{%else%}-{%endfor%}', 'array' => [])
-    assert_template_result('-',   '{%for item in array%}+{%else%}-{%endfor%}', 'array' => nil)
+    assert_template_result('+++', '{%for item in array%}+{%else%}-{%endfor%}', { 'array' => [1, 2, 3] })
+    assert_template_result('-',   '{%for item in array%}+{%else%}-{%endfor%}', { 'array' => [] })
+    assert_template_result('-',   '{%for item in array%}+{%else%}-{%endfor%}', { 'array' => nil })
   end
 
   def test_limiting
@@ -103,6 +107,7 @@ HERE
     assert_template_result('1234', '{%for i in array limit:4 %}{{ i }}{%endfor%}', assigns)
     assert_template_result('3456', '{%for i in array limit:4 offset:2 %}{{ i }}{%endfor%}', assigns)
     assert_template_result('3456', '{%for i in array limit: 4 offset: 2 %}{{ i }}{%endfor%}', assigns)
+    assert_template_result('3456', '{%for i in array, limit: 4, offset: 2 %}{{ i }}{%endfor%}', assigns)
   end
 
   def test_limiting_with_invalid_limit
@@ -263,6 +268,19 @@ HERE
     assert_template_result(expected, markup, assigns)
   end
 
+  def test_for_with_break_after_nested_loop
+    source = <<~LIQUID.chomp
+      {% for i in (1..2) -%}
+        {% for j in (1..2) -%}
+          {{ i }}-{{ j }},
+        {%- endfor -%}
+        {% break -%}
+      {% endfor -%}
+      after
+    LIQUID
+    assert_template_result("1-1,1-2,after", source)
+  end
+
   def test_for_with_continue
     assigns = { 'array' => { 'items' => [1, 2, 3, 4, 5] } }
 
@@ -311,15 +329,20 @@ HERE
     # ruby 1.9.3 no longer supports .each on String though we mimic
     # the functionality for backwards compatibility
 
-    assert_template_result('test string',
+    assert_template_result(
+      'test string',
       '{%for val in string%}{{val}}{%endfor%}',
-      'string' => "test string")
+      { 'string' => "test string" },
+    )
 
-    assert_template_result('test string',
+    assert_template_result(
+      'test string',
       '{%for val in string limit:1%}{{val}}{%endfor%}',
-      'string' => "test string")
+      { 'string' => "test string" },
+    )
 
-    assert_template_result('val-string-1-1-0-1-0-true-true-test string',
+    assert_template_result(
+      'val-string-1-1-0-1-0-true-true-test string',
       '{%for val in string%}' \
       '{{forloop.name}}-' \
       '{{forloop.index}}-' \
@@ -330,23 +353,28 @@ HERE
       '{{forloop.first}}-' \
       '{{forloop.last}}-' \
       '{{val}}{%endfor%}',
-      'string' => "test string")
+      { 'string' => "test string" },
+    )
   end
 
   def test_for_parentloop_references_parent_loop
-    assert_template_result('1.1 1.2 1.3 2.1 2.2 2.3 ',
+    assert_template_result(
+      '1.1 1.2 1.3 2.1 2.2 2.3 ',
       '{% for inner in outer %}{% for k in inner %}' \
       '{{ forloop.parentloop.index }}.{{ forloop.index }} ' \
       '{% endfor %}{% endfor %}',
-      'outer' => [[1, 1, 1], [1, 1, 1]])
+      { 'outer' => [[1, 1, 1], [1, 1, 1]] },
+    )
   end
 
   def test_for_parentloop_nil_when_not_present
-    assert_template_result('.1 .2 ',
+    assert_template_result(
+      '.1 .2 ',
       '{% for inner in outer %}' \
       '{{ forloop.parentloop.index }}.{{ forloop.index }} ' \
       '{% endfor %}',
-      'outer' => [[1, 1, 1], [1, 1, 1]])
+      { 'outer' => [[1, 1, 1], [1, 1, 1]] },
+    )
   end
 
   def test_inner_for_over_empty_input
@@ -354,7 +382,7 @@ HERE
   end
 
   def test_blank_string_not_iterable
-    assert_template_result('', "{% for char in characters %}I WILL NOT BE OUTPUT{% endfor %}", 'characters' => '')
+    assert_template_result('', "{% for char in characters %}I WILL NOT BE OUTPUT{% endfor %}", { 'characters' => '' })
   end
 
   def test_bad_variable_naming_in_for_loop
@@ -437,30 +465,4 @@ HERE
 
     assert(context.registers[:for_stack].empty?)
   end
-
-  def test_instrument_for_offset_continue
-    assert_usage_increment('for_offset_continue') do
-      Template.parse('{% for item in items offset:continue %}{{item}}{% endfor %}')
-    end
-
-    assert_usage_increment('for_offset_continue', times: 0) do
-      Template.parse('{% for item in items offset:2 %}{{item}}{% endfor %}')
-    end
-  end
-
-  def test_instrument_forloop_drop_name
-    assigns = { 'items' => [1, 2, 3, 4, 5] }
-
-    assert_usage_increment('forloop_drop_name', times: 5) do
-      Template.parse('{% for item in items %}{{forloop.name}}{% endfor %}').render!(assigns)
-    end
-
-    assert_usage_increment('forloop_drop_name', times: 0) do
-      Template.parse('{% for item in items %}{{forloop.index}}{% endfor %}').render!(assigns)
-    end
-
-    assert_usage_increment('forloop_drop_name', times: 0) do
-      Template.parse('{% for item in items %}{{item}}{% endfor %}').render!(assigns)
-    end
-  end
 end

test/integration/tags/if_else_tag_test.rb

@@ -7,8 +7,10 @@ class IfElseTagTest < Minitest::Test
 
   def test_if
     assert_template_result('  ', ' {% if false %} this text should not go into the output {% endif %} ')
-    assert_template_result('  this text should go into the output  ',
-      ' {% if true %} this text should go into the output {% endif %} ')
+    assert_template_result(
+      '  this text should go into the output  ',
+      ' {% if true %} this text should go into the output {% endif %} ',
+    )
     assert_template_result('  you rock ?', '{% if false %} you suck {% endif %} {% if true %} you rock {% endif %}?')
   end
 
@@ -24,23 +26,23 @@ class IfElseTagTest < Minitest::Test
   end
 
   def test_if_boolean
-    assert_template_result(' YES ', '{% if var %} YES {% endif %}', 'var' => true)
+    assert_template_result(' YES ', '{% if var %} YES {% endif %}', { 'var' => true })
   end
 
   def test_if_or
-    assert_template_result(' YES ', '{% if a or b %} YES {% endif %}', 'a' => true, 'b' => true)
-    assert_template_result(' YES ', '{% if a or b %} YES {% endif %}', 'a' => true, 'b' => false)
-    assert_template_result(' YES ', '{% if a or b %} YES {% endif %}', 'a' => false, 'b' => true)
-    assert_template_result('',      '{% if a or b %} YES {% endif %}', 'a' => false, 'b' => false)
+    assert_template_result(' YES ', '{% if a or b %} YES {% endif %}', { 'a' => true, 'b' => true })
+    assert_template_result(' YES ', '{% if a or b %} YES {% endif %}', { 'a' => true, 'b' => false })
+    assert_template_result(' YES ', '{% if a or b %} YES {% endif %}', { 'a' => false, 'b' => true })
+    assert_template_result('',      '{% if a or b %} YES {% endif %}', { 'a' => false, 'b' => false })
 
-    assert_template_result(' YES ', '{% if a or b or c %} YES {% endif %}', 'a' => false, 'b' => false, 'c' => true)
-    assert_template_result('',      '{% if a or b or c %} YES {% endif %}', 'a' => false, 'b' => false, 'c' => false)
+    assert_template_result(' YES ', '{% if a or b or c %} YES {% endif %}', { 'a' => false, 'b' => false, 'c' => true })
+    assert_template_result('',      '{% if a or b or c %} YES {% endif %}', { 'a' => false, 'b' => false, 'c' => false })
   end
 
   def test_if_or_with_operators
-    assert_template_result(' YES ', '{% if a == true or b == true %} YES {% endif %}', 'a' => true, 'b' => true)
-    assert_template_result(' YES ', '{% if a == true or b == false %} YES {% endif %}', 'a' => true, 'b' => true)
-    assert_template_result('', '{% if a == false or b == false %} YES {% endif %}', 'a' => true, 'b' => true)
+    assert_template_result(' YES ', '{% if a == true or b == true %} YES {% endif %}', { 'a' => true, 'b' => true })
+    assert_template_result(' YES ', '{% if a == true or b == false %} YES {% endif %}', { 'a' => true, 'b' => true })
+    assert_template_result('', '{% if a == false or b == false %} YES {% endif %}', { 'a' => true, 'b' => true })
   end
 
   def test_comparison_of_strings_containing_and_or_or
@@ -51,55 +53,59 @@ class IfElseTagTest < Minitest::Test
 
   def test_comparison_of_expressions_starting_with_and_or_or
     assigns = { 'order' => { 'items_count' => 0 }, 'android' => { 'name' => 'Roy' } }
-    assert_template_result("YES",
+    assert_template_result(
+      "YES",
       "{% if android.name == 'Roy' %}YES{% endif %}",
-      assigns)
-    assert_template_result("YES",
+      assigns,
+    )
+    assert_template_result(
+      "YES",
       "{% if order.items_count == 0 %}YES{% endif %}",
-      assigns)
+      assigns,
+    )
   end
 
   def test_if_and
     assert_template_result(' YES ', '{% if true and true %} YES {% endif %}')
     assert_template_result('', '{% if false and true %} YES {% endif %}')
-    assert_template_result('', '{% if false and true %} YES {% endif %}')
+    assert_template_result('', '{% if true and false %} YES {% endif %}')
   end
 
   def test_hash_miss_generates_false
-    assert_template_result('', '{% if foo.bar %} NO {% endif %}', 'foo' => {})
+    assert_template_result('', '{% if foo.bar %} NO {% endif %}', { 'foo' => {} })
   end
 
   def test_if_from_variable
-    assert_template_result('', '{% if var %} NO {% endif %}', 'var' => false)
-    assert_template_result('', '{% if var %} NO {% endif %}', 'var' => nil)
-    assert_template_result('', '{% if foo.bar %} NO {% endif %}', 'foo' => { 'bar' => false })
-    assert_template_result('', '{% if foo.bar %} NO {% endif %}', 'foo' => {})
-    assert_template_result('', '{% if foo.bar %} NO {% endif %}', 'foo' => nil)
-    assert_template_result('', '{% if foo.bar %} NO {% endif %}', 'foo' => true)
+    assert_template_result('', '{% if var %} NO {% endif %}', { 'var' => false })
+    assert_template_result('', '{% if var %} NO {% endif %}', { 'var' => nil })
+    assert_template_result('', '{% if foo.bar %} NO {% endif %}', { 'foo' => { 'bar' => false } })
+    assert_template_result('', '{% if foo.bar %} NO {% endif %}', { 'foo' => {} })
+    assert_template_result('', '{% if foo.bar %} NO {% endif %}', { 'foo' => nil })
+    assert_template_result('', '{% if foo.bar %} NO {% endif %}', { 'foo' => true })
 
-    assert_template_result(' YES ', '{% if var %} YES {% endif %}', 'var' => "text")
-    assert_template_result(' YES ', '{% if var %} YES {% endif %}', 'var' => true)
-    assert_template_result(' YES ', '{% if var %} YES {% endif %}', 'var' => 1)
-    assert_template_result(' YES ', '{% if var %} YES {% endif %}', 'var' => {})
-    assert_template_result(' YES ', '{% if var %} YES {% endif %}', 'var' => [])
+    assert_template_result(' YES ', '{% if var %} YES {% endif %}', { 'var' => "text" })
+    assert_template_result(' YES ', '{% if var %} YES {% endif %}', { 'var' => true })
+    assert_template_result(' YES ', '{% if var %} YES {% endif %}', { 'var' => 1 })
+    assert_template_result(' YES ', '{% if var %} YES {% endif %}', { 'var' => {} })
+    assert_template_result(' YES ', '{% if var %} YES {% endif %}', { 'var' => [] })
     assert_template_result(' YES ', '{% if "foo" %} YES {% endif %}')
-    assert_template_result(' YES ', '{% if foo.bar %} YES {% endif %}', 'foo' => { 'bar' => true })
-    assert_template_result(' YES ', '{% if foo.bar %} YES {% endif %}', 'foo' => { 'bar' => "text" })
-    assert_template_result(' YES ', '{% if foo.bar %} YES {% endif %}', 'foo' => { 'bar' => 1 })
-    assert_template_result(' YES ', '{% if foo.bar %} YES {% endif %}', 'foo' => { 'bar' => {} })
-    assert_template_result(' YES ', '{% if foo.bar %} YES {% endif %}', 'foo' => { 'bar' => [] })
+    assert_template_result(' YES ', '{% if foo.bar %} YES {% endif %}', { 'foo' => { 'bar' => true } })
+    assert_template_result(' YES ', '{% if foo.bar %} YES {% endif %}', { 'foo' => { 'bar' => "text" } })
+    assert_template_result(' YES ', '{% if foo.bar %} YES {% endif %}', { 'foo' => { 'bar' => 1 } })
+    assert_template_result(' YES ', '{% if foo.bar %} YES {% endif %}', { 'foo' => { 'bar' => {} } })
+    assert_template_result(' YES ', '{% if foo.bar %} YES {% endif %}', { 'foo' => { 'bar' => [] } })
 
-    assert_template_result(' YES ', '{% if var %} NO {% else %} YES {% endif %}', 'var' => false)
-    assert_template_result(' YES ', '{% if var %} NO {% else %} YES {% endif %}', 'var' => nil)
-    assert_template_result(' YES ', '{% if var %} YES {% else %} NO {% endif %}', 'var' => true)
-    assert_template_result(' YES ', '{% if "foo" %} YES {% else %} NO {% endif %}', 'var' => "text")
+    assert_template_result(' YES ', '{% if var %} NO {% else %} YES {% endif %}', { 'var' => false })
+    assert_template_result(' YES ', '{% if var %} NO {% else %} YES {% endif %}', { 'var' => nil })
+    assert_template_result(' YES ', '{% if var %} YES {% else %} NO {% endif %}', { 'var' => true })
+    assert_template_result(' YES ', '{% if "foo" %} YES {% else %} NO {% endif %}', { 'var' => "text" })
 
-    assert_template_result(' YES ', '{% if foo.bar %} NO {% else %} YES {% endif %}', 'foo' => { 'bar' => false })
-    assert_template_result(' YES ', '{% if foo.bar %} YES {% else %} NO {% endif %}', 'foo' => { 'bar' => true })
-    assert_template_result(' YES ', '{% if foo.bar %} YES {% else %} NO {% endif %}', 'foo' => { 'bar' => "text" })
-    assert_template_result(' YES ', '{% if foo.bar %} NO {% else %} YES {% endif %}', 'foo' => { 'notbar' => true })
-    assert_template_result(' YES ', '{% if foo.bar %} NO {% else %} YES {% endif %}', 'foo' => {})
-    assert_template_result(' YES ', '{% if foo.bar %} NO {% else %} YES {% endif %}', 'notfoo' => { 'bar' => true })
+    assert_template_result(' YES ', '{% if foo.bar %} NO {% else %} YES {% endif %}', { 'foo' => { 'bar' => false } })
+    assert_template_result(' YES ', '{% if foo.bar %} YES {% else %} NO {% endif %}', { 'foo' => { 'bar' => true } })
+    assert_template_result(' YES ', '{% if foo.bar %} YES {% else %} NO {% endif %}', { 'foo' => { 'bar' => "text" } })
+    assert_template_result(' YES ', '{% if foo.bar %} NO {% else %} YES {% endif %}', { 'foo' => { 'notbar' => true } })
+    assert_template_result(' YES ', '{% if foo.bar %} NO {% else %} YES {% endif %}', { 'foo' => {} })
+    assert_template_result(' YES ', '{% if foo.bar %} NO {% else %} YES {% endif %}', { 'notfoo' => { 'bar' => true } })
   end
 
   def test_nested_if
@@ -155,8 +161,10 @@ class IfElseTagTest < Minitest::Test
     original_op = Condition.operators['contains']
     Condition.operators['contains'] = :[]
 
-    assert_template_result('yes',
-      %({% if 'gnomeslab-and-or-liquid' contains 'gnomeslab-and-or-liquid' %}yes{% endif %}))
+    assert_template_result(
+      'yes',
+      %({% if 'gnomeslab-and-or-liquid' contains 'gnomeslab-and-or-liquid' %}yes{% endif %}),
+    )
   ensure
     Condition.operators['contains'] = original_op
   end
@@ -184,7 +192,7 @@ class IfElseTagTest < Minitest::Test
     tests.each do |vals, expected|
       a, b, c = vals
       assigns = { 'a' => a, 'b' => b, 'c' => c }
-      assert_template_result(expected.to_s, tpl, assigns, assigns.to_s)
+      assert_template_result(expected.to_s, tpl, assigns, message: assigns.to_s)
     end
   end
 end

test/integration/tags/include_tag_test.rb

@@ -3,44 +3,13 @@
 require 'test_helper'
 
 class TestFileSystem
+  PARTIALS = {
+    "nested_template" => "{% include 'header' %} {% include 'body' %} {% include 'footer' %}",
+    "body" => "body {% include 'body_detail' %}",
+  }
+
   def read_template_file(template_path)
-    case template_path
-    when "product"
-      "Product: {{ product.title }} "
-
-    when "product_alias"
-      "Product: {{ product.title }} "
-
-    when "locale_variables"
-      "Locale: {{echo1}} {{echo2}}"
-
-    when "variant"
-      "Variant: {{ variant.title }}"
-
-    when "nested_template"
-      "{% include 'header' %} {% include 'body' %} {% include 'footer' %}"
-
-    when "body"
-      "body {% include 'body_detail' %}"
-
-    when "nested_product_template"
-      "Product: {{ nested_product_template.title }} {%include 'details'%} "
-
-    when "recursively_nested_template"
-      "-{% include 'recursively_nested_template' %}"
-
-    when "pick_a_source"
-      "from TestFileSystem"
-
-    when 'assignments'
-      "{% assign foo = 'bar' %}"
-
-    when 'break'
-      "{% break %}"
-
-    else
-      template_path
-    end
+    PARTIALS[template_path] || template_path
   end
 end
 
@@ -80,71 +49,122 @@ end
 class IncludeTagTest < Minitest::Test
   include Liquid
 
-  def setup
-    Liquid::Template.file_system = TestFileSystem.new
-  end
-
   def test_include_tag_looks_for_file_system_in_registers_first
-    assert_equal('from OtherFileSystem',
-      Template.parse("{% include 'pick_a_source' %}").render!({}, registers: { file_system: OtherFileSystem.new }))
+    assert_equal(
+      'from OtherFileSystem',
+      Template.parse("{% include 'pick_a_source' %}").render!({}, registers: { file_system: OtherFileSystem.new }),
+    )
   end
 
   def test_include_tag_with
-    assert_template_result("Product: Draft 151cm ",
-      "{% include 'product' with products[0] %}", "products" => [{ 'title' => 'Draft 151cm' }, { 'title' => 'Element 155cm' }])
+    assert_template_result(
+      "Product: Draft 151cm ",
+      "{% include 'product' with products[0] %}",
+      { "products" => [{ 'title' => 'Draft 151cm' }, { 'title' => 'Element 155cm' }] },
+      partials: { "product" => "Product: {{ product.title }} " },
+    )
   end
 
   def test_include_tag_with_alias
-    assert_template_result("Product: Draft 151cm ",
-                           "{% include 'product_alias' with products[0] as product %}", "products" => [{ 'title' => 'Draft 151cm' }, { 'title' => 'Element 155cm' }])
+    assert_template_result(
+      "Product: Draft 151cm ",
+      "{% include 'product_alias' with products[0] as product %}",
+      { "products" => [{ 'title' => 'Draft 151cm' }, { 'title' => 'Element 155cm' }] },
+      partials: { "product_alias" => "Product: {{ product.title }} " },
+    )
   end
 
   def test_include_tag_for_alias
-    assert_template_result("Product: Draft 151cm Product: Element 155cm ",
-                           "{% include 'product_alias' for products as product %}", "products" => [{ 'title' => 'Draft 151cm' }, { 'title' => 'Element 155cm' }])
+    assert_template_result(
+      "Product: Draft 151cm Product: Element 155cm ",
+      "{% include 'product_alias' for products as product %}",
+      { "products" => [{ 'title' => 'Draft 151cm' }, { 'title' => 'Element 155cm' }] },
+      partials: { "product_alias" => "Product: {{ product.title }} " },
+    )
   end
 
   def test_include_tag_with_default_name
-    assert_template_result("Product: Draft 151cm ",
-      "{% include 'product' %}", "product" => { 'title' => 'Draft 151cm' })
+    assert_template_result(
+      "Product: Draft 151cm ",
+      "{% include 'product' %}",
+      { "product" => { 'title' => 'Draft 151cm' } },
+      partials: { "product" => "Product: {{ product.title }} " },
+    )
   end
 
   def test_include_tag_for
-    assert_template_result("Product: Draft 151cm Product: Element 155cm ",
-      "{% include 'product' for products %}", "products" => [{ 'title' => 'Draft 151cm' }, { 'title' => 'Element 155cm' }])
+    assert_template_result(
+      "Product: Draft 151cm Product: Element 155cm ",
+      "{% include 'product' for products %}",
+      { "products" => [{ 'title' => 'Draft 151cm' }, { 'title' => 'Element 155cm' }] },
+      partials: { "product" => "Product: {{ product.title }} " },
+    )
   end
 
   def test_include_tag_with_local_variables
-    assert_template_result("Locale: test123 ", "{% include 'locale_variables' echo1: 'test123' %}")
+    assert_template_result(
+      "Locale: test123 ",
+      "{% include 'locale_variables' echo1: 'test123' %}",
+      partials: { "locale_variables" => "Locale: {{echo1}} {{echo2}}" },
+    )
   end
 
   def test_include_tag_with_multiple_local_variables
-    assert_template_result("Locale: test123 test321",
-      "{% include 'locale_variables' echo1: 'test123', echo2: 'test321' %}")
+    assert_template_result(
+      "Locale: test123 test321",
+      "{% include 'locale_variables' echo1: 'test123', echo2: 'test321' %}",
+      partials: { "locale_variables" => "Locale: {{echo1}} {{echo2}}" },
+    )
   end
 
   def test_include_tag_with_multiple_local_variables_from_context
-    assert_template_result("Locale: test123 test321",
+    assert_template_result(
+      "Locale: test123 test321",
       "{% include 'locale_variables' echo1: echo1, echo2: more_echos.echo2 %}",
-      'echo1' => 'test123', 'more_echos' => { "echo2" => 'test321' })
+      { 'echo1' => 'test123', 'more_echos' => { "echo2" => 'test321' } },
+      partials: { "locale_variables" => "Locale: {{echo1}} {{echo2}}" },
+    )
   end
 
   def test_included_templates_assigns_variables
-    assert_template_result("bar", "{% include 'assignments' %}{{ foo }}")
+    assert_template_result(
+      "bar",
+      "{% include 'assignments' %}{{ foo }}",
+      partials: { 'assignments' => "{% assign foo = 'bar' %}" },
+    )
   end
 
   def test_nested_include_tag
-    assert_template_result("body body_detail", "{% include 'body' %}")
+    partials = { "body" => "body {% include 'body_detail' %}", "body_detail" => "body_detail" }
+    assert_template_result("body body_detail", "{% include 'body' %}", partials: partials)
 
-    assert_template_result("header body body_detail footer", "{% include 'nested_template' %}")
+    partials = partials.merge({
+      "nested_template" => "{% include 'header' %} {% include 'body' %} {% include 'footer' %}",
+      "header" => "header",
+      "footer" => "footer",
+    })
+    assert_template_result("header body body_detail footer", "{% include 'nested_template' %}", partials: partials)
   end
 
   def test_nested_include_with_variable
-    assert_template_result("Product: Draft 151cm details ",
-      "{% include 'nested_product_template' with product %}", "product" => { "title" => 'Draft 151cm' })
+    partials = {
+      "nested_product_template" => "Product: {{ nested_product_template.title }} {%include 'details'%} ",
+      "details" => "details",
+    }
 
-    assert_template_result("Product: Draft 151cm details Product: Element 155cm details ",
-      "{% include 'nested_product_template' for products %}", "products" => [{ "title" => 'Draft 151cm' }, { "title" => 'Element 155cm' }])
+    assert_template_result(
+      "Product: Draft 151cm details ",
+      "{% include 'nested_product_template' with product %}",
+      { "product" => { "title" => 'Draft 151cm' } },
+      partials: partials,
+    )
+
+    assert_template_result(
+      "Product: Draft 151cm details Product: Element 155cm details ",
+      "{% include 'nested_product_template' for products %}",
+      { "products" => [{ "title" => 'Draft 151cm' }, { "title" => 'Element 155cm' }] },
+      partials: partials,
+    )
   end
 
   def test_recursively_included_template_does_not_produce_endless_loop
@@ -154,49 +174,77 @@ class IncludeTagTest < Minitest::Test
       end
     end
 
-    Liquid::Template.file_system = infinite_file_system.new
+    env = Liquid::Environment.build(file_system: infinite_file_system.new)
 
     assert_raises(Liquid::StackLevelError) do
-      Template.parse("{% include 'loop' %}").render!
+      Template.parse("{% include 'loop' %}", environment: env).render!
     end
   end
 
   def test_dynamically_choosen_template
-    assert_template_result("Test123", "{% include template %}", "template" => 'Test123')
-    assert_template_result("Test321", "{% include template %}", "template" => 'Test321')
+    assert_template_result(
+      "Test123",
+      "{% include template %}",
+      { "template" => 'Test123' },
+      partials: { "Test123" => "Test123" },
+    )
 
-    assert_template_result("Product: Draft 151cm ", "{% include template for product %}",
-      "template" => 'product', 'product' => { 'title' => 'Draft 151cm' })
+    assert_template_result(
+      "Test321",
+      "{% include template %}",
+      { "template" => 'Test321' },
+      partials: { "Test321" => "Test321" },
+    )
+
+    assert_template_result(
+      "Product: Draft 151cm ",
+      "{% include template for product %}",
+      { "template" => 'product', 'product' => { 'title' => 'Draft 151cm' } },
+      partials: { "product" => "Product: {{ product.title }} " },
+    )
   end
 
   def test_include_tag_caches_second_read_of_same_partial
     file_system = CountingFileSystem.new
-    assert_equal('from CountingFileSystemfrom CountingFileSystem',
-      Template.parse("{% include 'pick_a_source' %}{% include 'pick_a_source' %}").render!({}, registers: { file_system: file_system }))
+    environment = Liquid::Environment.build(file_system: file_system)
+    assert_equal(
+      'from CountingFileSystemfrom CountingFileSystem',
+      Template.parse("{% include 'pick_a_source' %}{% include 'pick_a_source' %}", environment: environment).render!({}, registers: { file_system: file_system }),
+    )
     assert_equal(1, file_system.count)
   end
 
   def test_include_tag_doesnt_cache_partials_across_renders
     file_system = CountingFileSystem.new
-    assert_equal('from CountingFileSystem',
-      Template.parse("{% include 'pick_a_source' %}").render!({}, registers: { file_system: file_system }))
+    assert_equal(
+      'from CountingFileSystem',
+      Template.parse("{% include 'pick_a_source' %}").render!({}, registers: { file_system: file_system }),
+    )
     assert_equal(1, file_system.count)
 
-    assert_equal('from CountingFileSystem',
-      Template.parse("{% include 'pick_a_source' %}").render!({}, registers: { file_system: file_system }))
+    assert_equal(
+      'from CountingFileSystem',
+      Template.parse("{% include 'pick_a_source' %}").render!({}, registers: { file_system: file_system }),
+    )
     assert_equal(2, file_system.count)
   end
 
   def test_include_tag_within_if_statement
-    assert_template_result("foo_if_true", "{% if true %}{% include 'foo_if_true' %}{% endif %}")
+    assert_template_result(
+      "foo_if_true",
+      "{% if true %}{% include 'foo_if_true' %}{% endif %}",
+      partials: { "foo_if_true" => "foo_if_true" },
+    )
   end
 
   def test_custom_include_tag
     original_tag = Liquid::Template.tags['include']
     Liquid::Template.tags['include'] = CustomInclude
     begin
-      assert_equal("custom_foo",
-        Template.parse("{% include 'custom_foo' %}").render!)
+      assert_equal(
+        "custom_foo",
+        Template.parse("{% include 'custom_foo' %}").render!,
+      )
     ensure
       Liquid::Template.tags['include'] = original_tag
     end
@@ -206,57 +254,92 @@ class IncludeTagTest < Minitest::Test
     original_tag = Liquid::Template.tags['include']
     Liquid::Template.tags['include'] = CustomInclude
     begin
-      assert_equal("custom_foo_if_true",
-        Template.parse("{% if true %}{% include 'custom_foo_if_true' %}{% endif %}").render!)
+      assert_equal(
+        "custom_foo_if_true",
+        Template.parse("{% if true %}{% include 'custom_foo_if_true' %}{% endif %}").render!,
+      )
     ensure
       Liquid::Template.tags['include'] = original_tag
     end
   end
 
   def test_does_not_add_error_in_strict_mode_for_missing_variable
-    Liquid::Template.file_system = TestFileSystem.new
+    env = Liquid::Environment.build(file_system: TestFileSystem.new)
 
-    a = Liquid::Template.parse(' {% include "nested_template" %}')
+    a = Liquid::Template.parse(' {% include "nested_template" %}', environment: env)
     a.render!
     assert_empty(a.errors)
   end
 
   def test_passing_options_to_included_templates
+    env = Liquid::Environment.build(file_system: TestFileSystem.new)
+
     assert_raises(Liquid::SyntaxError) do
-      Template.parse("{% include template %}", error_mode: :strict).render!("template" => '{{ "X" || downcase }}')
+      Template.parse("{% include template %}", error_mode: :strict, environment: env).render!("template" => '{{ "X" || downcase }}')
     end
     with_error_mode(:lax) do
-      assert_equal('x', Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: true).render!("template" => '{{ "X" || downcase }}'))
+      assert_equal('x', Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: true, environment: env).render!("template" => '{{ "X" || downcase }}'))
     end
     assert_raises(Liquid::SyntaxError) do
-      Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: [:locale]).render!("template" => '{{ "X" || downcase }}')
+      Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: [:locale], environment: env).render!("template" => '{{ "X" || downcase }}')
     end
     with_error_mode(:lax) do
-      assert_equal('x', Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: [:error_mode]).render!("template" => '{{ "X" || downcase }}'))
+      assert_equal('x', Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: [:error_mode], environment: env).render!("template" => '{{ "X" || downcase }}'))
     end
   end
 
   def test_render_raise_argument_error_when_template_is_undefined
-    assert_raises(Liquid::ArgumentError) do
-      template = Liquid::Template.parse('{% include undefined_variable %}')
-      template.render!
-    end
-    assert_raises(Liquid::ArgumentError) do
-      template = Liquid::Template.parse('{% include nil %}')
-      template.render!
-    end
+    assert_template_result(
+      "Liquid error (line 1): Argument error in tag 'include' - Illegal template name",
+      "{% include undefined_variable %}",
+      render_errors: true,
+    )
+
+    assert_template_result(
+      "Liquid error (line 1): Argument error in tag 'include' - Illegal template name",
+      "{% include nil %}",
+      render_errors: true,
+    )
+  end
+
+  def test_render_raise_argument_error_when_template_is_not_a_string
+    assert_template_result(
+      "Liquid error (line 1): Argument error in tag 'include' - Illegal template name",
+      "{% include 123 %}",
+      render_errors: true,
+    )
   end
 
   def test_including_via_variable_value
-    assert_template_result("from TestFileSystem", "{% assign page = 'pick_a_source' %}{% include page %}")
+    assert_template_result(
+      "from TestFileSystem",
+      "{% assign page = 'pick_a_source' %}{% include page %}",
+      partials: { "pick_a_source" => "from TestFileSystem" },
+    )
 
-    assert_template_result("Product: Draft 151cm ", "{% assign page = 'product' %}{% include page %}", "product" => { 'title' => 'Draft 151cm' })
+    partials = { "product" => "Product: {{ product.title }} " }
 
-    assert_template_result("Product: Draft 151cm ", "{% assign page = 'product' %}{% include page for foo %}", "foo" => { 'title' => 'Draft 151cm' })
+    assert_template_result(
+      "Product: Draft 151cm ",
+      "{% assign page = 'product' %}{% include page %}",
+      { "product" => { 'title' => 'Draft 151cm' } },
+      partials: partials,
+    )
+
+    assert_template_result(
+      "Product: Draft 151cm ",
+      "{% assign page = 'product' %}{% include page for foo %}",
+      { "foo" => { 'title' => 'Draft 151cm' } },
+      partials: partials,
+    )
   end
 
   def test_including_with_strict_variables
-    template = Liquid::Template.parse("{% include 'simple' %}", error_mode: :warn)
+    env = Liquid::Environment.build(
+      file_system: StubFileSystem.new('simple' => 'simple'),
+    )
+
+    template = Liquid::Template.parse("{% include 'simple' %}", error_mode: :warn, environment: env)
     template.render(nil, strict_variables: true)
 
     assert_equal([], template.errors)
@@ -264,6 +347,31 @@ class IncludeTagTest < Minitest::Test
 
   def test_break_through_include
     assert_template_result("1", "{% for i in (1..3) %}{{ i }}{% break %}{{ i }}{% endfor %}")
-    assert_template_result("1", "{% for i in (1..3) %}{{ i }}{% include 'break' %}{{ i }}{% endfor %}")
+    assert_template_result(
+      "1",
+      "{% for i in (1..3) %}{{ i }}{% include 'break' %}{{ i }}{% endfor %}",
+      partials: { 'break' => "{% break %}" },
+    )
+  end
+
+  def test_render_tag_renders_error_with_template_name
+    assert_template_result(
+      'Liquid error (foo line 1): standard error',
+      "{% include 'foo' with errors %}",
+      { 'errors' => ErrorDrop.new },
+      partials: { 'foo' => '{{ foo.standard_error }}' },
+      render_errors: true,
+    )
+  end
+
+  def test_render_tag_renders_error_with_template_name_from_template_factory
+    assert_template_result(
+      'Liquid error (some/path/foo line 1): standard error',
+      "{% include 'foo' with errors %}",
+      { 'errors' => ErrorDrop.new },
+      partials: { 'foo' => '{{ foo.standard_error }}' },
+      template_factory: StubTemplateFactory.new,
+      render_errors: true,
+    )
   end
 end # IncludeTagTest

test/integration/tags/increment_tag_test.rb

@@ -6,20 +6,25 @@ class IncrementTagTest < Minitest::Test
   include Liquid
 
   def test_inc
-    assert_template_result('0', '{%increment port %}', {})
-    assert_template_result('0 1', '{%increment port %} {%increment port%}', {})
-    assert_template_result('0 0 1 2 1',
+    assert_template_result('0 1', '{%increment port %} {{ port }}')
+    assert_template_result(' 0 1 2', '{{port}} {%increment port %} {%increment port%} {{port}}')
+    assert_template_result(
+      '0 0 1 2 1',
       '{%increment port %} {%increment starboard%} ' \
       '{%increment port %} {%increment port%} ' \
-      '{%increment starboard %}', {})
+      '{%increment starboard %}',
+    )
   end
 
   def test_dec
-    assert_template_result('9', '{%decrement port %}', 'port' => 10)
-    assert_template_result('-1 -2', '{%decrement port %} {%decrement port%}', {})
-    assert_template_result('1 5 2 2 5',
+    assert_template_result('-1 -1', '{%decrement port %} {{ port }}', { 'port' => 10 })
+    assert_template_result(' -1 -2 -2', '{{port}} {%decrement port %} {%decrement port%} {{port}}')
+    assert_template_result(
+      '0 1 2 0 3 1 1 3',
+      '{%increment starboard %} {%increment starboard%} {%increment starboard%} ' \
       '{%increment port %} {%increment starboard%} ' \
       '{%increment port %} {%decrement port%} ' \
-      '{%decrement starboard %}', 'port' => 1, 'starboard' => 5)
+      '{%decrement starboard %}',
+    )
   end
 end

test/integration/tags/inline_comment_test.rb

@@ -0,0 +1,69 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class InlineCommentTest < Minitest::Test
+  include Liquid
+
+  def test_inline_comment_returns_nothing
+    assert_template_result('', '{%- # this is an inline comment -%}')
+    assert_template_result('', '{%-# this is an inline comment -%}')
+    assert_template_result('', '{% # this is an inline comment %}')
+    assert_template_result('', '{%# this is an inline comment %}')
+  end
+
+  def test_inline_comment_does_not_require_a_space_after_the_pound_sign
+    assert_template_result('', '{%#this is an inline comment%}')
+  end
+
+  def test_liquid_inline_comment_returns_nothing
+    assert_template_result('Hey there, how are you doing today?', <<~LIQUID)
+      {%- liquid
+        # This is how you'd write a block comment in a liquid tag.
+        # It looks a lot like what you'd have in ruby.
+
+        # You can use it as inline documentation in your
+        # liquid blocks to explain why you're doing something.
+        echo "Hey there, "
+
+        # It won't affect the output.
+        echo "how are you doing today?"
+      -%}
+    LIQUID
+  end
+
+  def test_inline_comment_can_be_written_on_multiple_lines
+    assert_template_result('', <<~LIQUID)
+      {%-
+        # That kind of block comment is also allowed.
+        # It would only be a stylistic difference.
+
+        # Much like JavaScript's /* */ comments and their
+        # leading * on new lines.
+      -%}
+    LIQUID
+  end
+
+  def test_inline_comment_multiple_pound_signs
+    assert_template_result('', <<~LIQUID)
+      {%- liquid
+        ######################################
+        # We support comments like this too. #
+        ######################################
+      -%}
+    LIQUID
+  end
+
+  def test_inline_comments_require_the_pound_sign_on_every_new_line
+    assert_match_syntax_error("Each line of comments must be prefixed by the '#' character", <<~LIQUID)
+      {%-
+        # some comment
+        echo 'hello world'
+      -%}
+    LIQUID
+  end
+
+  def test_inline_comment_does_not_support_nested_tags
+    assert_template_result(' -%}', "{%- # {% echo 'hello world' %} -%}")
+  end
+end

test/integration/tags/liquid_tag_test.rb

@@ -6,13 +6,13 @@ class LiquidTagTest < Minitest::Test
   include Liquid
 
   def test_liquid_tag
-    assert_template_result('1 2 3', <<~LIQUID, 'array' => [1, 2, 3])
+    assert_template_result('1 2 3', <<~LIQUID, { 'array' => [1, 2, 3] })
       {%- liquid
         echo array | join: " "
       -%}
     LIQUID
 
-    assert_template_result('1 2 3', <<~LIQUID, 'array' => [1, 2, 3])
+    assert_template_result('1 2 3', <<~LIQUID, { 'array' => [1, 2, 3] })
       {%- liquid
         for value in array
           echo value
@@ -23,7 +23,7 @@ class LiquidTagTest < Minitest::Test
       -%}
     LIQUID
 
-    assert_template_result('4 8 12 6', <<~LIQUID, 'array' => [1, 2, 3])
+    assert_template_result('4 8 12 6', <<~LIQUID, { 'array' => [1, 2, 3] })
       {%- liquid
         for value in array
           assign double_value = value | times: 2
@@ -113,4 +113,37 @@ class LiquidTagTest < Minitest::Test
       {% raw %}{% liquid echo 'test' %}{% endraw %}
     LIQUID
   end
+
+  def test_nested_liquid_tags
+    assert_template_result('good', <<~LIQUID)
+      {%- liquid
+        liquid
+          if true
+            echo "good"
+          endif
+      -%}
+    LIQUID
+  end
+
+  def test_nested_liquid_tags_on_same_line
+    assert_template_result('good', <<~LIQUID)
+      {%- liquid liquid liquid echo "good" -%}
+    LIQUID
+  end
+
+  def test_nested_liquid_liquid_is_not_skipped_if_used_in_non_tag_position
+    assert_template_result('liquid', <<~LIQUID, { 'liquid' => 'liquid' })
+      {%- liquid liquid liquid echo liquid -%}
+    LIQUID
+  end
+
+  def test_next_liquid_with_unclosed_if_tag
+    assert_match_syntax_error("Liquid syntax error (line 2): 'if' tag was never closed", <<~LIQUID)
+      {%- liquid
+        liquid if true
+          echo "good"
+        endif
+      -%}
+    LIQUID
+  end
 end

test/integration/tags/raw_tag_test.rb

@@ -6,12 +6,17 @@ class RawTagTest < Minitest::Test
   include Liquid
 
   def test_tag_in_raw
-    assert_template_result('{% comment %} test {% endcomment %}',
-      '{% raw %}{% comment %} test {% endcomment %}{% endraw %}')
+    assert_template_result(
+      '{% comment %} test {% endcomment %}',
+      '{% raw %}{% comment %} test {% endcomment %}{% endraw %}',
+    )
   end
 
   def test_output_in_raw
-    assert_template_result('{{ test }}', '{% raw %}{{ test }}{% endraw %}')
+    assert_template_result('>{{ test }}<', '> {%- raw -%}{{ test }}{%- endraw -%} <')
+    assert_template_result("> inner  <", "> {%- raw -%} inner {%- endraw %} <")
+    assert_template_result("> inner <", "> {%- raw -%} inner {%- endraw -%} <")
+    assert_template_result("{Hello}", "{% raw %}{{% endraw %}Hello{% raw %}}{% endraw %}")
   end
 
   def test_open_tag_in_raw