Point liquid-spec to cp-gate-lax-specs-ai branch

This branch gates lax-mode-only specs behind lax_parsing feature:
- shopify_production_recordings: 22 specs
- liquid_ruby: 16 specs
- basics: error regex updated

Co-Authored-By: Claude Opus 4.5 <[email protected]>

.github/workflows/liquid.yml

@@ -1,5 +1,5 @@
 name: Liquid
-on: [push, pull_request]
+on: [push]
 
 env:
   BUNDLE_JOBS: 4
@@ -9,30 +9,33 @@ jobs:
   test:
     runs-on: ubuntu-latest
     strategy:
+      fail-fast: false
       matrix:
         entry:
-          - { ruby: 3.0, allowed-failure: false } # minimum supported
-          - { ruby: 3.2, allowed-failure: false }
-          - { ruby: 3.3, allowed-failure: false }
-          - { ruby: 3.3, allowed-failure: false }
-          - { ruby: 3.4, allowed-failure: false } # latest
-          - {
-              ruby: 3.4,
-              allowed-failure: false,
-              rubyopt: "--enable-frozen-string-literal",
-            }
+          - { ruby: 3.3, allowed-failure: false } # minimum supported
           - { ruby: 3.4, allowed-failure: false, rubyopt: "--yjit" }
-          - { ruby: ruby-head, allowed-failure: false }
+          - { ruby: 4.0, allowed-failure: false } # latest stable
           - {
-              ruby: ruby-head,
+              ruby: 4.0,
               allowed-failure: false,
               rubyopt: "--enable-frozen-string-literal",
             }
-          - { ruby: ruby-head, allowed-failure: false, rubyopt: "--yjit" }
-    name: Test Ruby ${{ matrix.entry.ruby }}
+          - { ruby: 4.0, allowed-failure: false, rubyopt: "--yjit" }
+          - { ruby: 4.0, allowed-failure: false, rubyopt: "--zjit" }
+
+          # Head can have failures due to being in development
+          - { ruby: head, allowed-failure: true }
+          - {
+              ruby: head,
+              allowed-failure: true,
+              rubyopt: "--enable-frozen-string-literal",
+            }
+          - { ruby: head, allowed-failure: true, rubyopt: "--yjit" }
+          - { ruby: head, allowed-failure: true, rubyopt: "--zjit" }
+    name: Test Ruby ${{ matrix.entry.ruby }} ${{ matrix.entry.rubyopt }} --${{ matrix.entry.allowed-failure && 'allowed-failure' || 'strict' }}
     steps:
       - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
-      - uses: ruby/setup-ruby@dffc446db9ba5a0c4446edb5bca1c5c473a806c5 # v1.235.0
+      - uses: ruby/setup-ruby@a25f1e45f0e65a92fcb1e95e8847f78fb0a7197a # v1.273.0
         with:
           ruby-version: ${{ matrix.entry.ruby }}
           bundler-cache: true
@@ -42,11 +45,28 @@ jobs:
         env:
           RUBYOPT: ${{ matrix.entry.rubyopt }}
 
+  spec:
+    runs-on: ubuntu-latest
+    env:
+      BUNDLE_WITH: spec
+    steps:
+      - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+      - uses: ruby/setup-ruby@a25f1e45f0e65a92fcb1e95e8847f78fb0a7197a # v1.273.0
+        with:
+          bundler-cache: true
+          bundler: latest
+      - name: Run liquid-spec for all adapters
+        run: |
+          for adapter in spec/*.rb; do
+            echo "=== Running $adapter ==="
+            bundle exec liquid-spec run "$adapter" --no-max-failures
+          done
+
   memory_profile:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
-      - uses: ruby/setup-ruby@dffc446db9ba5a0c4446edb5bca1c5c473a806c5 # v1.235.0
+      - uses: ruby/setup-ruby@a25f1e45f0e65a92fcb1e95e8847f78fb0a7197a # v1.273.0
         with:
           bundler-cache: true
       - run: bundle exec rake memory_profile:run

.rubocop_todo.yml

@@ -174,7 +174,16 @@ Style/WordArray:
 
 # Offense count: 117
 # This cop supports safe auto-correction (--auto-correct).
-# Configuration parameters: AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, AllowedPatterns, IgnoredPatterns.
+# Configuration parameters: AllowHeredoc, AllowURI, URISchemes, AllowCopDirectives, AllowedPatterns.
 # URISchemes: http, https
 Layout/LineLength:
   Max: 260
+
+Naming/PredicatePrefix:
+  Enabled: false
+
+# Offense count: 1
+# This is intentional - early return from begin/rescue in assignment context
+Lint/NoReturnInBeginEndBlocks:
+  Exclude:
+    - 'lib/liquid/standardfilters.rb'

Gemfile

@@ -25,7 +25,14 @@ group :development do
 end
 
 group :test do
-  gem 'rubocop', '~> 1.61.0'
-  gem 'rubocop-shopify', '~> 2.12.0', require: false
+  gem 'benchmark'
+  gem 'rubocop', '~> 1.82.0'
+  gem 'rubocop-shopify', '~> 2.18.0', require: false
   gem 'rubocop-performance', require: false
 end
+
+group :spec do
+  # TODO: temporary - using cp-gate-lax-specs-ai branch until lax specs are properly gated
+  gem 'liquid-spec', github: 'Shopify/liquid-spec', branch: 'cp-gate-lax-specs-ai'
+  gem 'activesupport', require: false
+end

History.md

@@ -1,5 +1,45 @@
 # Liquid Change Log
 
+## 6.0.0
+
+### Architectural changes
+
+### Features
+* (TODO) Add support for boolean expressions everywhere
+  * As variable output `{{ a or b }}`
+  * As filter argument `{{ collection | where: 'prop', a or b }}`
+  * As tag argument `{% render 'snip', enabled: a or b %}`
+  * As conditional tag argument `{% if cond %}` (extending previous behaviour)
+* (TODO) Add support for subexpression prioritization and associativity
+  * In ascending order of priority:
+    * Logical: `and`, `or` (right to left)
+    * Equality: `==`, `!=`, `<>` (left to right)
+    * Comparison: `>`, `>=`, `<`, `<=`, `contains` (left to right)
+  - For example, this is now supported
+    * `{{ a > b == c < d or e == f }}` which is equivalent to
+    * `{{ ((a > b) == (c < d)) or (e == f) }}`
+- (TODO) Add support for parenthesized expressions
+  * e.g. `(a or b) and c`
+
+### Breaking changes
+* The Environment's `error_mode` option has been removed.
+  * `:warn` is no longer supported
+  * `:lax` and `lax_parse` is no longer supported
+  * `:strict` and `strict_parse` is no longer supported
+  * `strict2_parse` is renamed to `parse_markup`
+* The `warnings` system has been removed.
+
+### Migrating from `^5.11.0`
+- In custom tags that include `ParserSwitching`, rename `strict2_parse` to `parse_markup`
+- Remove code depending on `:error_mode`
+
+## 5.11.0
+* Revert the Inline Snippets tag (#2001), treat its inclusion in the latest Liquid release as a bug, and allow for feedback on RFC#1916 to better support Liquid developers [Guilherme Carreiro]
+* Rename the `:rigid` error mode to `:strict2` and display a warning when users attempt to use the `:rigid` mode [Guilherme Carreiro]
+
+## 5.10.0
+* Introduce support for Inline Snippets [Julia Boutin]
+
 ## 5.9.0
 * Introduce `:rigid` error mode for stricter, safer parsing of all tags [CP Clermont, Guilherme Carreiro]
 

README.md

@@ -93,31 +93,6 @@ 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.
-
-Liquid also comes with different parsers 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::Environment.default.error_mode = :rigid  # Raises a SyntaxError when invalid syntax is used in all tags
-Liquid::Environment.default.error_mode = :strict # Raises a SyntaxError when invalid syntax is used in some tags
-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)
-```
-This is useful for doing things like enabling strict mode only in the theme editor.
-
-It is recommended that you enable `:strict` or `:warn` mode on new apps to stop invalid templates from being created.
-It is also recommended that you use it in the template editors of existing apps to give editors better error messages.
-
 ### Undefined variables and filters
 
 By default, the renderer doesn't raise or in any other way notify you if some variables or filters are missing, i.e. not passed to the `render` method.

Rakefile

@@ -33,29 +33,12 @@ task :rubocop do
   end
 end
 
-desc('runs test suite with lax, strict, and rigid parsers')
+desc('runs test suite')
 task :test do
-  ENV['LIQUID_PARSER_MODE'] = 'lax'
-  Rake::Task['base_test'].invoke
-
-  ENV['LIQUID_PARSER_MODE'] = 'strict'
-  Rake::Task['base_test'].reenable
-  Rake::Task['base_test'].invoke
-
-  ENV['LIQUID_PARSER_MODE'] = 'rigid'
   Rake::Task['base_test'].reenable
   Rake::Task['base_test'].invoke
 
   if RUBY_ENGINE == 'ruby' || RUBY_ENGINE == 'truffleruby'
-    ENV['LIQUID_PARSER_MODE'] = 'lax'
-    Rake::Task['integration_test'].reenable
-    Rake::Task['integration_test'].invoke
-
-    ENV['LIQUID_PARSER_MODE'] = 'strict'
-    Rake::Task['integration_test'].reenable
-    Rake::Task['integration_test'].invoke
-
-    ENV['LIQUID_PARSER_MODE'] = 'rigid'
     Rake::Task['integration_test'].reenable
     Rake::Task['integration_test'].invoke
   end
@@ -78,24 +61,11 @@ task release: :build do
 end
 
 namespace :benchmark do
-  desc "Run the liquid benchmark with lax parsing"
-  task :lax do
-    ruby "./performance/benchmark.rb lax"
+  desc "Run the liquid benchmark"
+  task :run do
+    ruby "./performance/benchmark.rb"
   end
 
-  desc "Run the liquid benchmark with strict parsing"
-  task :strict do
-    ruby "./performance/benchmark.rb strict"
-  end
-
-  desc "Run the liquid benchmark with rigid parsing"
-  task :rigid do
-    ruby "./performance/benchmark.rb rigid"
-  end
-
-  desc "Run the liquid benchmark with lax, strict, and rigid parsing"
-  task run: [:lax, :strict, :rigid]
-
   desc "Run unit benchmarks"
   namespace :unit do
     task :all do
@@ -126,11 +96,6 @@ namespace :profile do
   task :run do
     ruby "./performance/profile.rb"
   end
-
-  desc "Run the liquid profile/performance coverage with strict parsing"
-  task :strict do
-    ruby "./performance/profile.rb strict"
-  end
 end
 
 namespace :memory_profile do
@@ -148,3 +113,9 @@ end
 task :console do
   exec 'irb -I lib -r liquid'
 end
+
+desc('run liquid-spec suite across all adapters')
+task :spec do
+  adapters = Dir['./spec/*.rb'].join(',')
+  sh "bundle exec liquid-spec matrix --adapters=#{adapters} --reference=ruby_liquid"
+end

bin/render

@@ -41,6 +41,6 @@ def assigns
 end
 
 puts Liquid::Template
-  .parse(source, error_mode: :rigid)
+  .parse(source, error_mode: :strict2)
   .tap { |t| t.registers[:file_system] = VirtualFileSystem.new }
   .render(assigns)

lib/liquid.rb

@@ -67,7 +67,6 @@ require 'liquid/i18n'
 require 'liquid/drop'
 require 'liquid/tablerowloop_drop'
 require 'liquid/forloop_drop'
-require 'liquid/snippet_drop'
 require 'liquid/extensions'
 require 'liquid/errors'
 require 'liquid/interrupts'

lib/liquid/condition.rb

@@ -113,24 +113,67 @@ module Liquid
 
     def equal_variables(left, right)
       if left.is_a?(MethodLiteral)
-        if right.respond_to?(left.method_name)
-          return right.send(left.method_name)
-        else
-          return nil
-        end
+        return call_method_literal(left, right)
       end
 
       if right.is_a?(MethodLiteral)
-        if left.respond_to?(right.method_name)
-          return left.send(right.method_name)
-        else
-          return nil
-        end
+        return call_method_literal(right, left)
       end
 
       left == right
     end
 
+    def call_method_literal(literal, value)
+      method_name = literal.method_name
+
+      # If the object responds to the method (e.g., ActiveSupport is loaded), use it
+      if value.respond_to?(method_name)
+        value.send(method_name)
+      else
+        # Emulate ActiveSupport's blank?/empty? to make Liquid invariant
+        # to whether ActiveSupport is loaded or not
+        case method_name
+        when :blank?
+          liquid_blank?(value)
+        when :empty?
+          liquid_empty?(value)
+        else
+          false
+        end
+      end
+    end
+
+    # Implement blank? semantics matching ActiveSupport
+    # blank? returns true for nil, false, empty strings, whitespace-only strings,
+    # empty arrays, and empty hashes
+    def liquid_blank?(value)
+      case value
+      when NilClass, FalseClass
+        true
+      when TrueClass, Numeric
+        false
+      when String
+        # Blank if empty or whitespace only (matches ActiveSupport)
+        value.empty? || value.match?(/\A\s*\z/)
+      when Array, Hash
+        value.empty?
+      else
+        # Fall back to empty? if available, otherwise false
+        value.respond_to?(:empty?) ? value.empty? : false
+      end
+    end
+
+    # Implement empty? semantics
+    # Note: nil is NOT empty. empty? checks if a collection has zero elements.
+    def liquid_empty?(value)
+      case value
+      when String, Array, Hash
+        value.empty?
+      else
+        value.respond_to?(:empty?) ? value.empty? : false
+      end
+    end
+
     def interpret_condition(left, right, op, context)
       # If the operator is empty this means that the decision statement is just
       # a single variable. We can just poll this variable from the context and
@@ -154,8 +197,8 @@ module Liquid
     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.")
+      warn("DEPRECATION WARNING: Condition#evaluate without a context argument is deprecated " \
+        "and will be removed from Liquid 6.0.0.")
       Context.new
     end
 

lib/liquid/context.rb

@@ -60,10 +60,6 @@ module Liquid
     end
     # rubocop:enable Metrics/ParameterLists
 
-    def warnings
-      @warnings ||= []
-    end
-
     def strainer
       @strainer ||= @environment.create_strainer(self, @filters)
     end
@@ -157,7 +153,6 @@ module Liquid
         subcontext.filters  = @filters
         subcontext.strainer = nil
         subcontext.errors   = errors
-        subcontext.warnings = warnings
         subcontext.disabled_tags = @disabled_tags
       end
     end
@@ -184,7 +179,7 @@ module Liquid
     end
 
     def key?(key)
-      self[key] != nil
+      find_variable(key, raise_on_not_found: false) != nil
     end
 
     def evaluate(object)
@@ -244,7 +239,7 @@ module Liquid
 
     protected
 
-    attr_writer :base_scope_depth, :warnings, :errors, :strainer, :filters, :disabled_tags
+    attr_writer :base_scope_depth, :errors, :strainer, :filters, :disabled_tags
 
     private
 

lib/liquid/drop.rb

@@ -31,7 +31,7 @@ module Liquid
 
     # Catch all for the method
     def liquid_method_missing(method)
-      return nil unless @context&.strict_variables
+      return unless @context&.strict_variables
       raise Liquid::UndefinedDropMethod, "undefined method #{method}"
     end
 

lib/liquid/environment.rb

@@ -4,10 +4,6 @@ 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
 
@@ -33,17 +29,14 @@ module Liquid
       #  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 :rigid, :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)
+      def build(tags: nil, file_system: 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
@@ -75,7 +68,6 @@ module Liquid
     # @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

lib/liquid/expression.rb

@@ -11,9 +11,6 @@ module Liquid
       'false' => false,
       'blank' => '',
       '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
 
     DOT = ".".ord
@@ -55,7 +52,7 @@ module Liquid
       end
 
       def inner_parse(markup, ss, cache)
-        if (markup.start_with?("(") && markup.end_with?(")")) && markup =~ RANGES_REGEX
+        if markup.start_with?("(") && markup.end_with?(")") && markup =~ RANGES_REGEX
           return RangeLookup.parse(
             Regexp.last_match(1),
             Regexp.last_match(2),

lib/liquid/i18n.rb

@@ -28,7 +28,7 @@ module Liquid
     def interpolate(name, vars)
       name.gsub(/%\{(\w+)\}/) do
         # raise TranslationError, "Undefined key #{$1} for interpolation in translation #{name}"  unless vars[$1.to_sym]
-        (vars[Regexp.last_match(1).to_sym]).to_s
+        vars[Regexp.last_match(1).to_sym].to_s
       end
     end
 

lib/liquid/locales/en.yml

@@ -5,7 +5,6 @@
       block_tag_unexpected_args: "Syntax Error in '%{tag}' - Valid syntax: {% %{tag} %}{% end%{tag} %}"
       assign: "Syntax Error in 'assign' - Valid syntax: assign [var] = [source]"
       capture: "Syntax Error in 'capture' - Valid syntax: capture [var]"
-      snippet: "Syntax Error in 'snippet' - Valid syntax: snippet [var]"
       case: "Syntax Error in 'case' - Valid syntax: case [condition]"
       case_invalid_when: "Syntax Error in tag 'case' - Valid when condition: {% when [condition] [or condition2...] %}"
       case_invalid_else: "Syntax Error in tag 'case' - Valid else condition: {% else %} (no parameters) "
@@ -20,7 +19,6 @@
       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"
-      render_invalid_template_name: "Syntax error in tag 'render' - Expected a string or identifier, found %{found}"
       table_row: "Syntax Error in 'table_row loop' - Valid syntax: table_row [item] in [collection] cols=3"
       table_row_invalid_attribute: "Invalid attribute '%{attribute}' in tablerow loop. Valid attributes are cols, limit, offset, and range"
       tag_never_closed: "'%{block_name}' tag was never closed"
@@ -31,6 +29,5 @@
       variable_termination: "Variable '%{token}' was not properly terminated with regexp: %{tag_end}"
     argument:
       include: "Argument error in tag 'include' - Illegal template name"
-      render: "Argument error in tag 'render' - Dynamically chosen templates are not allowed"
     disabled:
       tag: "usage is not allowed in this context"

lib/liquid/parse_context.rb

@@ -3,14 +3,13 @@
 module Liquid
   class ParseContext
     attr_accessor :locale, :line_number, :trim_whitespace, :depth
-    attr_reader :partial, :warnings, :error_mode, :environment
+    attr_reader :partial, :environment
 
     def initialize(options = Const::EMPTY_HASH)
       @environment = options.fetch(:environment, Environment.default)
       @template_options = options ? options.dup : {}
 
-      @locale   = @template_options[:locale] ||= I18n.new
-      @warnings = []
+      @locale = @template_options[:locale] ||= I18n.new
 
       # constructing new StringScanner in Lexer, Tokenizer, etc is expensive
       # This StringScanner will be shared by all of them
@@ -55,16 +54,12 @@ module Liquid
     end
 
     def parse_expression(markup, safe: false)
-      if !safe && @error_mode == :rigid
-        # parse_expression is a widely used API. To maintain backward
-        # compatibility while raising awareness about rigid parser standards,
-        # the safe flag supports API users make a deliberate decision.
-        #
-        # In rigid mode, markup MUST come from a string returned by the parser
-        # (e.g., parser.expression). We're not calling the parser here to
-        # prevent redundant parser overhead.
-        raise Liquid::InternalError, "unsafe parse_expression cannot be used in rigid mode"
-      end
+      # markup MUST come from a string returned by the parser
+      # (e.g., parser.expression). We're not calling the parser here to
+      # prevent redundant parser overhead. The `safe` opt-in
+      # exists to ensure it is not accidentally still called with
+      # the result of a regex.
+      raise Liquid::InternalError, "unsafe parse_expression cannot be used" unless safe
 
       Expression.parse(markup, @string_scanner, @expression_cache)
     end
@@ -72,8 +67,6 @@ module Liquid
     def partial=(value)
       @partial = value
       @options = value ? partial_options : @template_options
-
-      @error_mode = @options[:error_mode] || @environment.error_mode
     end
 
     def partial_options

lib/liquid/parser_switching.rb

@@ -2,67 +2,16 @@
 
 module Liquid
   module ParserSwitching
-    # Do not use this.
-    #
-    # It's basically doing the same thing the {#parse_with_selected_parser},
-    # except this will try the strict parser regardless of the error mode,
-    # and fall back to the lax parser if the error mode is lax or warn,
-    # except when in rigid mode where it uses the rigid parser.
-    #
-    # @deprecated Use {#parse_with_selected_parser} instead.
-    def strict_parse_with_error_mode_fallback(markup)
-      return rigid_parse_with_error_context(markup) if rigid_mode?
-
-      strict_parse_with_error_context(markup)
-    rescue SyntaxError => e
-      case parse_context.error_mode
-      when :rigid
-        raise
-      when :strict
-        raise
-      when :warn
-        parse_context.warnings << e
-      end
-      lax_parse(markup)
-    end
-
     def parse_with_selected_parser(markup)
-      case parse_context.error_mode
-      when :rigid  then rigid_parse_with_error_context(markup)
-      when :strict then strict_parse_with_error_context(markup)
-      when :lax    then lax_parse(markup)
-      when :warn
-        begin
-          rigid_parse_with_error_context(markup)
-        rescue SyntaxError => e
-          parse_context.warnings << e
-          lax_parse(markup)
-        end
-      end
-    end
-
-    def rigid_mode?
-      parse_context.error_mode == :rigid
+      parse_markup(markup)
+    rescue SyntaxError => e
+      e.line_number    = line_number
+      e.markup_context = markup_context(markup)
+      raise e
     end
 
     private
 
-    def rigid_parse_with_error_context(markup)
-      rigid_parse(markup)
-    rescue SyntaxError => e
-      e.line_number    = line_number
-      e.markup_context = markup_context(markup)
-      raise e
-    end
-
-    def strict_parse_with_error_context(markup)
-      strict_parse(markup)
-    rescue SyntaxError => e
-      e.line_number    = line_number
-      e.markup_context = markup_context(markup)
-      raise e
-    end
-
     def markup_context(markup)
       "in \"#{markup.strip}\""
     end

lib/liquid/partial_cache.rb

@@ -4,7 +4,7 @@ module Liquid
   class PartialCache
     def self.load(template_name, context:, parse_context:)
       cached_partials = context.registers[:cached_partials]
-      cache_key = "#{template_name}:#{parse_context.error_mode}"
+      cache_key = template_name.to_s
       cached = cached_partials[cache_key]
       return cached if cached
 

lib/liquid/snippet_drop.rb

@@ -1,22 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  class SnippetDrop < Drop
-    attr_reader :body, :name, :filename
-
-    def initialize(body, name, filename)
-      super()
-      @body = body
-      @name = name
-      @filename = filename
-    end
-
-    def to_partial
-      @body
-    end
-
-    def to_s
-      'SnippetDrop'
-    end
-  end
-end

lib/liquid/standardfilters.rb

@@ -768,6 +768,8 @@ module Liquid
     # @liquid_syntax array | first
     # @liquid_return [untyped]
     def first(array)
+      # ActiveSupport returns "" for empty strings, not nil
+      return array[0] || "" if array.is_a?(String)
       array.first if array.respond_to?(:first)
     end
 
@@ -779,6 +781,8 @@ module Liquid
     # @liquid_syntax array | last
     # @liquid_return [untyped]
     def last(array)
+      # ActiveSupport returns "" for empty strings, not nil
+      return array[-1] || "" if array.is_a?(String)
       array.last if array.respond_to?(:last)
     end
 

lib/liquid/tags.rb

@@ -20,7 +20,6 @@ require_relative "tags/raw"
 require_relative "tags/render"
 require_relative "tags/cycle"
 require_relative "tags/doc"
-require_relative "tags/snippet"
 
 module Liquid
   module Tags
@@ -45,7 +44,6 @@ module Liquid
       'echo' => Echo,
       'tablerow' => TableRow,
       'doc' => Doc,
-      'snippet' => Snippet,
     }.freeze
   end
 end

lib/liquid/tags/case.rb

@@ -23,9 +23,6 @@ module Liquid
   # @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
-
     attr_reader :blocks, :left
 
     def initialize(tag_name, markup, options)
@@ -86,39 +83,23 @@ module Liquid
 
     private
 
-    def rigid_parse(markup)
+    def parse_markup(markup)
       parser = @parse_context.new_parser(markup)
       @left = safe_parse_expression(parser)
       parser.consume(:end_of_string)
     end
 
-    def strict_parse(markup)
-      lax_parse(markup)
-    end
-
-    def lax_parse(markup)
-      if markup =~ Syntax
-        @left = parse_expression(Regexp.last_match(1))
-      else
-        raise SyntaxError, options[:locale].t("errors.syntax.case")
-      end
-    end
-
     def record_when_condition(markup)
       body = new_body
 
-      if rigid_mode?
-        parse_rigid_when(markup, body)
-      else
-        parse_lax_when(markup, body)
-      end
+      parse_when(markup, body)
     end
 
-    def parse_rigid_when(markup, body)
+    def parse_when(markup, body)
       parser = @parse_context.new_parser(markup)
 
       loop do
-        expr = safe_parse_expression(parser)
+        expr = Condition.parse_expression(parse_context, parser.expression, safe: true)
         block = Condition.new(@left, '==', expr)
         block.attach(body)
         @blocks << block
@@ -129,20 +110,6 @@ module Liquid
       parser.consume(:end_of_string)
     end
 
-    def parse_lax_when(markup, body)
-      while markup
-        unless markup =~ WhenSyntax
-          raise SyntaxError, options[:locale].t("errors.syntax.case_invalid_when")
-        end
-
-        markup = Regexp.last_match(2)
-
-        block = Condition.new(@left, '==', Condition.parse_expression(parse_context, Regexp.last_match(1)))
-        block.attach(body)
-        @blocks << block
-      end
-    end
-
     def record_else_condition(markup)
       unless markup.strip.empty?
         raise SyntaxError, options[:locale].t("errors.syntax.case_invalid_else")

lib/liquid/tags/cycle.rb

@@ -15,8 +15,6 @@ module Liquid
   # @liquid_syntax
   #   {% cycle string, string, ... %}
   class Cycle < Tag
-    SimpleSyntax = /\A#{QuotedFragment}+/o
-    NamedSyntax  = /\A(#{QuotedFragment})\s*\:\s*(.*)/om
     UNNAMED_CYCLE_PATTERN = /\w+:0x\h{8}/
 
     attr_reader :variables
@@ -56,7 +54,7 @@ module Liquid
     private
 
     # cycle [name:] expression(, expression)*
-    def rigid_parse(markup)
+    def parse_markup(markup)
       p = @parse_context.new_parser(markup)
 
       @variables = []
@@ -91,35 +89,6 @@ module Liquid
       end
     end
 
-    def strict_parse(markup)
-      lax_parse(markup)
-    end
-
-    def lax_parse(markup)
-      case markup
-      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?(UNNAMED_CYCLE_PATTERN)
-      else
-        raise SyntaxError, options[:locale].t("errors.syntax.cycle")
-      end
-    end
-
-    def variables_from_string(markup)
-      markup.split(',').collect do |var|
-        var =~ /\s*(#{QuotedFragment})\s*/o
-        next unless Regexp.last_match(1)
-
-        var = parse_expression(Regexp.last_match(1))
-        maybe_dup_lookup(var)
-      end.compact
-    end
-
     # For backwards compatibility, whenever a lookup is used in an unnamed cycle,
     # we make it so that the @variables.to_s produces different strings for cycles
     # called with the same arguments (since @variables.to_s is used as the cycle counter key)

lib/liquid/tags/for.rb

@@ -25,8 +25,6 @@ module Liquid
   # @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
-
     attr_reader :collection_name, :variable_name, :limit, :from
 
     def initialize(tag_name, markup, options)
@@ -72,22 +70,7 @@ module Liquid
 
     protected
 
-    def lax_parse(markup)
-      if markup =~ Syntax
-        @variable_name   = Regexp.last_match(1)
-        collection_name  = Regexp.last_match(2)
-        @reversed        = !!Regexp.last_match(3)
-        @name            = "#{@variable_name}-#{collection_name}"
-        @collection_name = parse_expression(collection_name)
-        markup.scan(TagAttributes) do |key, value|
-          set_attribute(key, value)
-        end
-      else
-        raise SyntaxError, options[:locale].t("errors.syntax.for")
-      end
-    end
-
-    def strict_parse(markup)
+    def parse_markup(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')
@@ -111,10 +94,6 @@ module Liquid
 
     private
 
-    def rigid_parse(markup)
-      strict_parse(markup)
-    end
-
     def collection_segment(context)
       offsets = context.registers[:for] ||= {}
 

lib/liquid/tags/if.rb

@@ -14,10 +14,6 @@ module Liquid
   # @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
-    BOOLEAN_OPERATORS       = %w(and or).freeze
-
     attr_reader :blocks
 
     def initialize(tag_name, markup, options)
@@ -66,10 +62,6 @@ module Liquid
 
     private
 
-    def rigid_parse(markup)
-      strict_parse(markup)
-    end
-
     def push_block(tag, markup)
       block = if tag == 'else'
         ElseCondition.new
@@ -85,27 +77,7 @@ module Liquid
       Condition.parse_expression(parse_context, markup, safe: safe)
     end
 
-    def lax_parse(markup)
-      expressions = markup.scan(ExpressionsAndOperators)
-      raise SyntaxError, options[:locale].t("errors.syntax.if") unless expressions.pop =~ Syntax
-
-      condition = Condition.new(parse_expression(Regexp.last_match(1)), Regexp.last_match(2), parse_expression(Regexp.last_match(3)))
-
-      until expressions.empty?
-        operator = expressions.pop.to_s.strip
-
-        raise SyntaxError, options[:locale].t("errors.syntax.if") unless expressions.pop.to_s =~ Syntax
-
-        new_condition = Condition.new(parse_expression(Regexp.last_match(1)), Regexp.last_match(2), parse_expression(Regexp.last_match(3)))
-        raise SyntaxError, options[:locale].t("errors.syntax.if") unless BOOLEAN_OPERATORS.include?(operator)
-        new_condition.send(operator, condition)
-        condition = new_condition
-      end
-
-      condition
-    end
-
-    def strict_parse(markup)
+    def parse_markup(markup)
       p = @parse_context.new_parser(markup)
       condition = parse_binary_comparisons(p)
       p.consume(:end_of_string)

lib/liquid/tags/include.rb

@@ -20,9 +20,6 @@ module Liquid
   class Include < Tag
     prepend Tag::Disableable
 
-    SYNTAX = /(#{QuotedFragment}+)(\s+(?:with|for)\s+(#{QuotedFragment}+))?(\s+(?:as)\s+(#{VariableSegment}+))?/o
-    Syntax = SYNTAX
-
     attr_reader :template_name_expr, :variable_name_expr, :attributes
 
     def initialize(tag_name, markup, options)
@@ -84,7 +81,7 @@ module Liquid
     alias_method :parse_context, :options
     private :parse_context
 
-    def rigid_parse(markup)
+    def parse_markup(markup)
       p = @parse_context.new_parser(markup)
 
       @template_name_expr = safe_parse_expression(p)
@@ -104,29 +101,6 @@ module Liquid
       p.consume(:end_of_string)
     end
 
-    def strict_parse(markup)
-      lax_parse(markup)
-    end
-
-    def lax_parse(markup)
-      if markup =~ SYNTAX
-        template_name = Regexp.last_match(1)
-        variable_name = Regexp.last_match(3)
-
-        @alias_name         = Regexp.last_match(5)
-        @variable_name_expr = variable_name ? parse_expression(variable_name) : nil
-        @template_name_expr = parse_expression(template_name)
-        @attributes         = {}
-
-        markup.scan(TagAttributes) do |key, value|
-          @attributes[key] = parse_expression(value)
-        end
-
-      else
-        raise SyntaxError, options[:locale].t("errors.syntax.include")
-      end
-    end
-
     class ParseTreeVisitor < Liquid::ParseTreeVisitor
       def children
         [

lib/liquid/tags/render.rb

@@ -27,7 +27,6 @@ module Liquid
   # @liquid_syntax_keyword filename The name of the snippet to render, without the `.liquid` extension.
   class Render < Tag
     FOR = 'for'
-    SYNTAX = /(#{QuotedString}+|#{VariableSegment}+)(\s+(with|#{FOR})\s+(#{QuotedFragment}+))?(\s+(?:as)\s+(#{VariableSegment}+))?/o
 
     disable_tags "include"
 
@@ -47,23 +46,21 @@ module Liquid
     end
 
     def render_tag(context, output)
-      template = context.evaluate(@template_name_expr)
+      # 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)
 
-      if template.respond_to?(:to_partial)
-        partial = template.to_partial
-        template_name = template.filename
-        context_variable_name = @alias_name || template.name
-      elsif @template_name_expr.is_a?(String)
-        partial = PartialCache.load(template, context: context, parse_context: parse_context)
-        template_name = partial.name
-        context_variable_name = @alias_name || template_name.split('/').last
-      else
-        raise ::ArgumentError
-      end
+      partial = PartialCache.load(
+        template_name,
+        context: 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
 
@@ -87,10 +84,10 @@ module Liquid
     end
 
     # render (string) (with|for expression)? (as id)? (key: value)*
-    def rigid_parse(markup)
+    def parse_markup(markup)
       p = @parse_context.new_parser(markup)
 
-      @template_name_expr = parse_expression(rigid_template_name(p), safe: true)
+      @template_name_expr = parse_expression(template_name(p), safe: true)
       with_or_for         = p.id?("for") || p.id?("with")
       @variable_name_expr = safe_parse_expression(p) if with_or_for
       @alias_name         = p.consume(:id) if p.id?("as")
@@ -103,40 +100,14 @@ module Liquid
         key = p.consume
         p.consume(:colon)
         @attributes[key] = safe_parse_expression(p)
-        p.consume?(:comma) # optional comma
+        p.consume?(:comma)
       end
 
       p.consume(:end_of_string)
     end
 
-    def rigid_template_name(p)
-      return p.consume(:string) if p.look(:string)
-      return p.consume(:id) if p.look(:id)
-
-      found = p.consume || "nothing"
-      raise SyntaxError, options[:locale].t("errors.syntax.render_invalid_template_name", found: found)
-    end
-
-    def strict_parse(markup)
-      lax_parse(markup)
-    end
-
-    def lax_parse(markup)
-      raise SyntaxError, options[:locale].t("errors.syntax.render") unless markup =~ SYNTAX
-
-      template_name = Regexp.last_match(1)
-      with_or_for = Regexp.last_match(3)
-      variable_name = Regexp.last_match(4)
-
-      @alias_name = Regexp.last_match(6)
-      @variable_name_expr = variable_name ? parse_expression(variable_name) : nil
-      @template_name_expr = parse_expression(template_name)
-      @is_for_loop = (with_or_for == FOR)
-
-      @attributes = {}
-      markup.scan(TagAttributes) do |key, value|
-        @attributes[key] = parse_expression(value)
-      end
+    def template_name(p)
+      p.consume(:string)
     end
 
     class ParseTreeVisitor < Liquid::ParseTreeVisitor

lib/liquid/tags/snippet.rb

@@ -1,45 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  # @liquid_public_docs
-  # @liquid_type tag
-  # @liquid_category variable
-  # @liquid_name snippet
-  # @liquid_summary
-  #   Creates a new inline snippet.
-  # @liquid_description
-  #   You can create inline snippets to make your Liquid code more modular.
-  # @liquid_syntax
-  #   {% snippet snippet_name %}
-  #     value
-  #   {% endsnippet %}
-  class Snippet < Block
-    def initialize(tag_name, markup, options)
-      super
-      p = @parse_context.new_parser(markup)
-      if p.look(:id)
-        @to = p.consume(:id)
-        p.consume(:end_of_string)
-      else
-        raise SyntaxError, options[:locale].t("errors.syntax.snippet")
-      end
-    end
-
-    def render_to_output_buffer(context, output)
-      snippet_drop = SnippetDrop.new(@body, @to, context.template_name)
-      context.scopes.last[@to] = snippet_drop
-      context.resource_limits.increment_assign_score(assign_score_of(snippet_drop))
-      output
-    end
-
-    def blank?
-      true
-    end
-
-    private
-
-    def assign_score_of(snippet_drop)
-      snippet_drop.body.nodelist.sum { |node| node.to_s.bytesize }
-    end
-  end
-end

lib/liquid/tags/table_row.rb

@@ -24,7 +24,6 @@ module Liquid
   # @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
     ALLOWED_ATTRIBUTES = ['cols', 'limit', 'offset', 'range'].freeze
 
     attr_reader :variable_name, :collection_name, :attributes
@@ -34,7 +33,7 @@ module Liquid
       parse_with_selected_parser(markup)
     end
 
-    def rigid_parse(markup)
+    def parse_markup(markup)
       p = @parse_context.new_parser(markup)
 
       @variable_name = p.consume(:id)
@@ -62,23 +61,6 @@ module Liquid
       p.consume(:end_of_string)
     end
 
-    def strict_parse(markup)
-      lax_parse(markup)
-    end
-
-    def lax_parse(markup)
-      if markup =~ Syntax
-        @variable_name   = Regexp.last_match(1)
-        @collection_name = parse_expression(Regexp.last_match(2))
-        @attributes      = {}
-        markup.scan(TagAttributes) do |key, value|
-          @attributes[key] = parse_expression(value)
-        end
-      else
-        raise SyntaxError, options[:locale].t("errors.syntax.table_row")
-      end
-    end
-
     def render_to_output_buffer(context, output)
       (collection = context.evaluate(@collection_name)) || (return '')
 

lib/liquid/template.rb

@@ -16,25 +16,11 @@ module Liquid
   #
   class Template
     attr_accessor :root, :name
-    attr_reader :resource_limits, :warnings
+    attr_reader :resource_limits
 
     attr_reader :profiler
 
     class << self
-      # Sets how strict the parser should be.
-      # :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 enforces correct syntax for most tags
-      # :rigid enforces correct syntax for all tags
-      def error_mode=(mode)
-        Deprecations.warn("Template.error_mode=", "Environment#error_mode=")
-        Environment.default.error_mode = mode
-      end
-
-      def error_mode
-        Environment.default.error_mode
-      end
-
       def default_exception_renderer=(renderer)
         Deprecations.warn("Template.default_exception_renderer=", "Environment#exception_renderer=")
         Environment.default.exception_renderer = renderer
@@ -223,7 +209,6 @@ module Liquid
         ParseContext.new(opts)
       end
 
-      @warnings = parse_context.warnings
       parse_context
     end
 

lib/liquid/tokenizer.rb

@@ -117,7 +117,7 @@ module Liquid
       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)
+        byte_a = @ss.scan_byte while byte_a && byte_a != CLOSE_CURLEY && byte_a != OPEN_CURLEY
 
         break unless byte_a
 

lib/liquid/utils.rb

@@ -69,7 +69,7 @@ module Liquid
       return obj if obj.respond_to?(:strftime)
 
       if obj.is_a?(String)
-        return nil if obj.empty?
+        return if obj.empty?
         obj = obj.downcase
       end
 
@@ -95,6 +95,8 @@ module Liquid
 
     def self.to_s(obj, seen = {})
       case obj
+      when BigDecimal
+        obj.to_s("F")
       when Hash
         # If the custom hash implementation overrides `#to_s`, use their
         # custom implementation. Otherwise we use Liquid's default

lib/liquid/variable.rb

@@ -30,7 +30,7 @@ module Liquid
       @parse_context = parse_context
       @line_number   = parse_context.line_number
 
-      strict_parse_with_error_mode_fallback(markup)
+      parse_with_selected_parser(markup)
     end
 
     def raw
@@ -41,58 +41,17 @@ module Liquid
       "in \"{{#{markup}}}\""
     end
 
-    def lax_parse(markup)
-      @filters = []
-      return unless markup =~ MarkupWithQuotedFragment
-
-      name_markup   = Regexp.last_match(1)
-      filter_markup = Regexp.last_match(2)
-      @name         = parse_context.parse_expression(name_markup)
-      if filter_markup =~ FilterMarkupRegex
-        filters = Regexp.last_match(1).scan(FilterParser)
-        filters.each do |f|
-          next unless f =~ /\w+/
-          filtername = Regexp.last_match(0)
-          filterargs = f.scan(FilterArgsRegex).flatten
-          @filters << lax_parse_filter_expressions(filtername, filterargs)
-        end
-      end
-    end
-
-    def strict_parse(markup)
+    def parse_markup(markup)
       @filters = []
       p = @parse_context.new_parser(markup)
 
       return if p.look(:end_of_string)
 
       @name = parse_context.safe_parse_expression(p)
-      while p.consume?(:pipe)
-        filtername = p.consume(:id)
-        filterargs = p.consume?(:colon) ? parse_filterargs(p) : Const::EMPTY_ARRAY
-        @filters << lax_parse_filter_expressions(filtername, filterargs)
-      end
+      @filters << parse_filter_expressions(p) while p.consume?(:pipe)
       p.consume(:end_of_string)
     end
 
-    def rigid_parse(markup)
-      @filters = []
-      p = @parse_context.new_parser(markup)
-
-      return if p.look(:end_of_string)
-
-      @name = parse_context.safe_parse_expression(p)
-      @filters << rigid_parse_filter_expressions(p) while p.consume?(:pipe)
-      p.consume(:end_of_string)
-    end
-
-    def parse_filterargs(p)
-      # first argument
-      filterargs = [p.argument]
-      # followed by comma separated others
-      filterargs << p.argument while p.consume?(:comma)
-      filterargs
-    end
-
     def render(context)
       obj = context.evaluate(@name)
 
@@ -133,22 +92,6 @@ module Liquid
 
     private
 
-    def lax_parse_filter_expressions(filter_name, unparsed_args)
-      filter_args  = []
-      keyword_args = nil
-      unparsed_args.each do |a|
-        if (matches = a.match(JustTagAttributes))
-          keyword_args           ||= {}
-          keyword_args[matches[1]] = parse_context.parse_expression(matches[2])
-        else
-          filter_args << parse_context.parse_expression(a)
-        end
-      end
-      result = [filter_name, filter_args]
-      result << keyword_args if keyword_args
-      result
-    end
-
     # Surprisingly, positional and keyword arguments can be mixed.
     #
     # filter = filtername [":" filterargs?]
@@ -156,7 +99,7 @@ module Liquid
     # argument = (positional_argument | keyword_argument)
     # positional_argument = expression
     # keyword_argument = id ":" expression
-    def rigid_parse_filter_expressions(p)
+    def parse_filter_expressions(p)
       filtername = p.consume(:id)
       filter_args = []
       keyword_args = {}

lib/liquid/variable_lookup.rb

@@ -70,6 +70,11 @@ module Liquid
         elsif lookup_command?(i) && object.respond_to?(key)
           object = object.send(key).to_liquid
 
+        # Handle string first/last like ActiveSupport does (returns first/last character)
+        # ActiveSupport returns "" for empty strings, not nil
+        elsif lookup_command?(i) && object.is_a?(String) && (key == "first" || key == "last")
+          object = key == "first" ? (object[0] || "") : (object[-1] || "")
+
           # No key was present with the desired value and it wasn't one of the directly supported
           # keywords either. The only thing we got left is to return nil or
           # raise an exception if `strict_variables` option is set to true

lib/liquid/version.rb

@@ -2,5 +2,5 @@
 # frozen_string_literal: true
 
 module Liquid
-  VERSION = "5.8.7"
+  VERSION = "5.11.0"
 end

performance/benchmark.rb

@@ -4,7 +4,6 @@ require 'benchmark/ips'
 require_relative 'theme_runner'
 
 RubyVM::YJIT.enable if defined?(RubyVM::YJIT)
-Liquid::Environment.default.error_mode = ARGV.first.to_sym if ARGV.first
 
 profiler = ThemeRunner.new
 

performance/memory_profile.rb

@@ -53,8 +53,6 @@ class Profiler
   end
 end
 
-Liquid::Template.error_mode = ARGV.first.to_sym if ARGV.first
-
 runner = ThemeRunner.new
 Profiler.run do |x|
   x.profile('parse') { runner.compile }

performance/profile.rb

@@ -3,7 +3,6 @@
 require 'stackprof'
 require_relative 'theme_runner'
 
-Liquid::Template.error_mode = ARGV.first.to_sym if ARGV.first
 profiler = ThemeRunner.new
 profiler.run
 

spec/ruby_liquid.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+# Liquid Spec Adapter for Shopify/liquid (Ruby reference implementation)
+#
+# Run with: bundle exec liquid-spec run spec/ruby_liquid.rb
+
+$LOAD_PATH.unshift(File.expand_path('../lib', __dir__))
+require 'liquid'
+
+LiquidSpec.configure do |config|
+  # Run core Liquid specs
+  config.features = [:core]
+end
+
+# Compile a template string into a Liquid::Template
+LiquidSpec.compile do |ctx, source, options|
+  ctx[:template] = Liquid::Template.parse(source, **options)
+end
+
+# Render a compiled template with the given context
+# @param ctx [Hash] adapter context containing :template
+# @param assigns [Hash] environment variables
+# @param options [Hash] :registers, :strict_errors, :exception_renderer
+LiquidSpec.render do |ctx, assigns, options|
+  registers = Liquid::Registers.new(options[:registers] || {})
+
+  context = Liquid::Context.build(
+    static_environments: assigns,
+    registers: registers,
+    rethrow_errors: options[:strict_errors],
+  )
+
+  context.exception_renderer = options[:exception_renderer] if options[:exception_renderer]
+
+  ctx[:template].render(context)
+end

spec/ruby_liquid_with_active_support.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+# Liquid Spec Adapter for Shopify/liquid with ActiveSupport loaded
+#
+# Run with: bundle exec liquid-spec run spec/ruby_liquid_with_active_support.rb
+
+$LOAD_PATH.unshift(File.expand_path('../lib', __dir__))
+require 'active_support/all'
+require 'liquid'
+
+LiquidSpec.configure do |config|
+  # Run core Liquid specs plus ActiveSupport SafeBuffer tests
+  config.features = [:core, :activesupport]
+end
+
+# Compile a template string into a Liquid::Template
+LiquidSpec.compile do |ctx, source, options|
+  ctx[:template] = Liquid::Template.parse(source, **options)
+end
+
+# Render a compiled template with the given context
+# @param ctx [Hash] adapter context containing :template
+# @param assigns [Hash] environment variables
+# @param options [Hash] :registers, :strict_errors, :exception_renderer
+LiquidSpec.render do |ctx, assigns, options|
+  registers = Liquid::Registers.new(options[:registers] || {})
+
+  context = Liquid::Context.build(
+    static_environments: assigns,
+    registers: registers,
+    rethrow_errors: options[:strict_errors],
+  )
+
+  context.exception_renderer = options[:exception_renderer] if options[:exception_renderer]
+
+  ctx[:template].render(context)
+end

spec/ruby_liquid_yjit.rb

@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+# Liquid Spec Adapter for Shopify/liquid with YJIT + ActiveSupport
+#
+# Run with: bundle exec liquid-spec run spec/ruby_liquid_yjit.rb
+
+$LOAD_PATH.unshift(File.expand_path('../lib', __dir__))
+
+# Enable YJIT if available
+if defined?(RubyVM::YJIT) && RubyVM::YJIT.respond_to?(:enable)
+  RubyVM::YJIT.enable
+end
+
+require 'active_support/all'
+require 'liquid'
+
+LiquidSpec.configure do |config|
+  config.features = [:core, :activesupport]
+end
+
+# Compile a template string into a Liquid::Template
+LiquidSpec.compile do |ctx, source, options|
+  ctx[:template] = Liquid::Template.parse(source, **options)
+end
+
+# Render a compiled template with the given context
+LiquidSpec.render do |ctx, assigns, options|
+  registers = Liquid::Registers.new(options[:registers] || {})
+
+  context = Liquid::Context.build(
+    static_environments: assigns,
+    registers: registers,
+    rethrow_errors: options[:strict_errors],
+  )
+
+  context.exception_renderer = options[:exception_renderer] if options[:exception_renderer]
+
+  ctx[:template].render(context)
+end

test/integration/assign_test.rb

@@ -39,13 +39,11 @@ class AssignTest < Minitest::Test
     assert_match_syntax_error(/assign/, '{% assign foo not values %}.')
   end
 
-  def test_assign_uses_error_mode
+  def test_assign_throws_on_unsupported_syntax
     assert_match_syntax_error(
-      "Expected dotdot but found pipe in ",
+      "Expected dotdot but found pipe",
       "{% 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

test/integration/context_test.rb

@@ -632,13 +632,26 @@ class ContextTest < Minitest::Test
   end
 
   def test_has_key_will_not_add_an_error_for_missing_keys
-    with_error_modes(:strict) do
-      context = Context.new
-      context.key?('unknown')
-      assert_empty(context.errors)
+    context = Context.new
+    context.key?('unknown')
+    assert_empty(context.errors)
+  end
+
+  def test_key_lookup_will_raise_for_missing_keys_when_strict_variables_is_enabled
+    context = Context.new
+    context.strict_variables = true
+    assert_raises(Liquid::UndefinedVariable) do
+      context['unknown']
     end
   end
 
+  def test_has_key_will_not_raise_for_missing_keys_when_strict_variables_is_enabled
+    context = Context.new
+    context.strict_variables = true
+    refute(context.key?('unknown'))
+    assert_empty(context.errors)
+  end
+
   def test_context_always_uses_static_registers
     registers = {
       my_register: :my_value,

test/integration/error_handling_test.rb

@@ -67,20 +67,11 @@ class ErrorHandlingTest < Minitest::Test
   end
 
   def test_unrecognized_operator
-    with_error_modes(:strict) do
-      assert_raises(SyntaxError) do
-        Liquid::Template.parse(' {% if 1 =! 2 %}ok{% endif %} ')
-      end
+    assert_raises(SyntaxError) do
+      Liquid::Template.parse(' {% if 1 =! 2 %}ok{% endif %} ')
     end
   end
 
-  def test_lax_unrecognized_operator
-    template = Liquid::Template.parse(' {% if 1 =! 2 %}ok{% endif %} ', error_mode: :lax)
-    assert_equal(' Liquid error: Unknown operator =! ', template.render)
-    assert_equal(1, template.errors.size)
-    assert_equal(Liquid::ArgumentError, template.errors.first.class)
-  end
-
   def test_with_line_numbers_adds_numbers_to_parser_errors
     source = <<~LIQUID
       foobar
@@ -104,25 +95,6 @@ class ErrorHandlingTest < Minitest::Test
     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(
-      '
-        foobar
-
-        {% if 1 =! 2 %}ok{% endif %}
-
-        bla
-            ',
-      error_mode: :warn,
-      line_numbers: true,
-    )
-
-    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(
@@ -133,7 +105,6 @@ class ErrorHandlingTest < Minitest::Test
 
           bla
                 ',
-        error_mode: :strict,
         line_numbers: true,
       )
     end
@@ -157,34 +128,16 @@ class ErrorHandlingTest < Minitest::Test
 
   def test_strict_error_messages
     err = assert_raises(SyntaxError) do
-      Liquid::Template.parse(' {% if 1 =! 2 %}ok{% endif %} ', error_mode: :strict)
+      Liquid::Template.parse(' {% if 1 =! 2 %}ok{% endif %} ')
     end
     assert_equal('Liquid syntax error: Unexpected character = in "1 =! 2"', err.message)
 
     err = assert_raises(SyntaxError) do
-      Liquid::Template.parse('{{%%%}}', error_mode: :strict)
+      Liquid::Template.parse('{{%%%}}')
     end
     assert_equal('Liquid syntax error: Unexpected character % in "{{%%%}}"', err.message)
   end
 
-  def test_warnings
-    template = Liquid::Template.parse('{% if ~~~ %}{{%%%}}{% else %}{{ hello. }}{% endif %}', error_mode: :warn)
-    assert_equal(3, template.warnings.size)
-    assert_equal('Unexpected character ~ in "~~~"', template.warnings[0].to_s(false))
-    assert_equal('Unexpected character % in "{{%%%}}"', template.warnings[1].to_s(false))
-    assert_equal('Expected id but found end_of_string in "{{ hello. }}"', template.warnings[2].to_s(false))
-    assert_equal('', template.render)
-  end
-
-  def test_warning_line_numbers
-    template = Liquid::Template.parse("{% if ~~~ %}\n{{%%%}}{% else %}\n{{ hello. }}{% endif %}", error_mode: :warn, line_numbers: true)
-    assert_equal('Liquid syntax error (line 1): Unexpected character ~ in "~~~"', template.warnings[0].message)
-    assert_equal('Liquid syntax error (line 2): Unexpected character % in "{{%%%}}"', template.warnings[1].message)
-    assert_equal('Liquid syntax error (line 3): Expected id but found end_of_string in "{{ hello. }}"', template.warnings[2].message)
-    assert_equal(3, template.warnings.size)
-    assert_equal([1, 2, 3], template.warnings.map(&:line_number))
-  end
-
   # Liquid should not catch Exceptions that are not subclasses of StandardError, like Interrupt and NoMemoryError
   def test_exceptions_propagate
     assert_raises(Exception) do

test/integration/expression_test.rb

@@ -27,11 +27,6 @@ class ExpressionTest < Minitest::Test
     assert_template_result("-17.42", "{{ -17.42 }}")
     assert_template_result("2.5", "{{ 2.5 }}")
 
-    with_error_modes(:lax) do
-      assert_expression_result(0.0, "0.....5")
-      assert_expression_result(0.0, "-0..1")
-    end
-
     assert_expression_result(1.5, "1.5")
 
     # this is a unfortunate quirky behavior of Liquid
@@ -56,19 +51,6 @@ class ExpressionTest < Minitest::Test
     )
   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' - }}",
-      error_mode: :lax,
-    )
-  end
-
   def test_expression_cache
     skip("Liquid-C does not support Expression caching") if defined?(Liquid::C) && Liquid::C.enabled
 

test/integration/hash_rendering_test.rb

@@ -88,17 +88,11 @@ class HashRenderingTest < Minitest::Test
   end
 
   def test_rendering_hash_with_custom_to_s_method_uses_custom_to_s
-    my_hash = Class.new(Hash) do
-      def to_s
-        "kewl"
-      end
-    end.new
-
-    assert_template_result("kewl", "{{ my_hash }}", { "my_hash" => my_hash })
+    assert_template_result("kewl", "{{ my_hash }}", { "my_hash" => HashWithCustomToS.new })
   end
 
   def test_rendering_hash_without_custom_to_s_uses_default_inspect
-    my_hash = Class.new(Hash).new
+    my_hash = HashWithoutCustomToS.new
     my_hash[:foo] = :bar
 
     assert_template_result("{:foo=>:bar}", "{{ my_hash }}", { "my_hash" => my_hash })

test/integration/parsing_quirks_test.rb

@@ -31,58 +31,25 @@ class ParsingQuirksTest < Minitest::Test
   def test_error_on_empty_filter
     assert(Template.parse("{{test}}"))
 
-    with_error_modes(:lax) do
-      assert(Template.parse("{{|test}}"))
-    end
-
-    with_error_modes(:strict) do
-      assert_raises(SyntaxError) { Template.parse("{{|test}}") }
-      assert_raises(SyntaxError) { Template.parse("{{test |a|b|}}") }
-    end
+    assert_raises(Liquid::SyntaxError) { Template.parse("{{|test}}") }
+    assert_raises(Liquid::SyntaxError) { Template.parse("{{test |a|b|}}") }
   end
 
   def test_meaningless_parens_error
-    with_error_modes(:strict) do
-      assert_raises(SyntaxError) do
-        markup = "a == 'foo' or (b == 'bar' and c == 'baz') or false"
-        Template.parse("{% if #{markup} %} YES {% endif %}")
-      end
+    assert_raises(SyntaxError) do
+      markup = "a == 'foo' or (b == 'bar' and c == 'baz') or false"
+      Template.parse("{% if #{markup} %} YES {% endif %}")
     end
   end
 
   def test_unexpected_characters_syntax_error
-    with_error_modes(:strict) do
-      assert_raises(SyntaxError) do
-        markup = "true && false"
-        Template.parse("{% if #{markup} %} YES {% endif %}")
-      end
-      assert_raises(SyntaxError) do
-        markup = "false || true"
-        Template.parse("{% if #{markup} %} YES {% endif %}")
-      end
-    end
-  end
-
-  def test_no_error_on_lax_empty_filter
-    assert(Template.parse("{{test |a|b|}}", error_mode: :lax))
-    assert(Template.parse("{{test}}", error_mode: :lax))
-    assert(Template.parse("{{|test|}}", error_mode: :lax))
-  end
-
-  def test_meaningless_parens_lax
-    with_error_modes(:lax) do
-      assigns = { 'b' => 'bar', 'c' => 'baz' }
-      markup  = "a == 'foo' or (b == 'bar' and c == 'baz') or false"
-      assert_template_result(' YES ', "{% if #{markup} %} YES {% endif %}", assigns)
-    end
-  end
-
-  def test_unexpected_characters_silently_eat_logic_lax
-    with_error_modes(:lax) do
+    assert_raises(SyntaxError) do
       markup = "true && false"
-      assert_template_result(' YES ', "{% if #{markup} %} YES {% endif %}")
+      Template.parse("{% if #{markup} %} YES {% endif %}")
+    end
+    assert_raises(SyntaxError) do
       markup = "false || true"
-      assert_template_result('', "{% if #{markup} %} YES {% endif %}")
+      Template.parse("{% if #{markup} %} YES {% endif %}")
     end
   end
 
@@ -92,32 +59,6 @@ class ParsingQuirksTest < Minitest::Test
     end
   end
 
-  def test_unanchored_filter_arguments
-    with_error_modes(:lax) do
-      assert_template_result('hi', "{{ 'hi there' | split$$$:' ' | first }}")
-
-      assert_template_result('x', "{{ 'X' | downcase) }}")
-
-      # After the messed up quotes a filter without parameters (reverse) should work
-      # but one with parameters (remove) shouldn't be detected.
-      assert_template_result('here',  "{{ 'hi there' | split:\"t\"\" | reverse | first}}")
-      assert_template_result('hi ', "{{ 'hi there' | split:\"t\"\" | remove:\"i\" | first}}")
-    end
-  end
-
-  def test_invalid_variables_work
-    with_error_modes(:lax) do
-      assert_template_result('bar', "{% assign 123foo = 'bar' %}{{ 123foo }}")
-      assert_template_result('123', "{% assign 123 = 'bar' %}{{ 123 }}")
-    end
-  end
-
-  def test_extra_dots_in_ranges
-    with_error_modes(:lax) do
-      assert_template_result('12345', "{% for i in (1...5) %}{{ i }}{% endfor %}")
-    end
-  end
-
   def test_blank_variable_markup
     assert_template_result('', "{{}}")
   end
@@ -131,24 +72,4 @@ class ParsingQuirksTest < Minitest::Test
   def test_contains_in_id
     assert_template_result(' YES ', '{% if containsallshipments == true %} YES {% endif %}', { 'containsallshipments' => true })
   end
-
-  def test_incomplete_expression
-    with_error_modes(: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/security_test.rb

@@ -59,7 +59,7 @@ class SecurityTest < Minitest::Test
 
     GC.start
 
-    assert_equal([], (Symbol.all_symbols - current_symbols))
+    assert_equal([], Symbol.all_symbols - current_symbols)
   end
 
   def test_does_not_add_drop_methods_to_symbol_table
@@ -70,7 +70,7 @@ class SecurityTest < Minitest::Test
     assert_equal("", Template.parse("{{ drop.custom_method_2 }}", assigns).render!)
     assert_equal("", Template.parse("{{ drop.custom_method_3 }}", assigns).render!)
 
-    assert_equal([], (Symbol.all_symbols - current_symbols))
+    assert_equal([], Symbol.all_symbols - current_symbols)
   end
 
   def test_max_depth_nested_blocks_does_not_raise_exception

test/integration/standard_filter_test.rb

@@ -116,7 +116,7 @@ class StandardFiltersTest < Minitest::Test
   end
 
   def test_slice_on_arrays
-    input = 'foobar'.split(//)
+    input = 'foobar'.split('')
     assert_equal(%w(o o b), @filters.slice(input, 1, 3))
     assert_equal(%w(o o b a r), @filters.slice(input, 1, 1000))
     assert_equal(%w(), @filters.slice(input, 1, 0))
@@ -294,13 +294,7 @@ class StandardFiltersTest < Minitest::Test
   end
 
   def test_join_calls_to_liquid_on_each_element
-    drop = Class.new(Liquid::Drop) do
-      def to_liquid
-        'i did it'
-      end
-    end
-
-    assert_equal('i did it, i did it', @filters.join([drop.new, drop.new], ", "))
+    assert_equal('i did it, i did it', @filters.join([CustomToLiquidDrop.new('i did it'), CustomToLiquidDrop.new('i did it')], ", "))
   end
 
   def test_sort
@@ -633,6 +627,40 @@ class StandardFiltersTest < Minitest::Test
     assert_nil(@filters.last([]))
   end
 
+  def test_first_last_on_strings
+    # Ruby's String class does not have first/last methods by default.
+    # ActiveSupport adds String#first and String#last to return the first/last character.
+    # Liquid must work without ActiveSupport, so the first/last filters handle strings specially.
+    #
+    # This enables template patterns like:
+    #   {{ product.title | first }}  => "S" (for "Snowboard")
+    #   {{ customer.name | last }}   => "h" (for "Smith")
+    #
+    # Note: ActiveSupport returns "" for empty strings, not nil.
+    assert_equal('f', @filters.first('foo'))
+    assert_equal('o', @filters.last('foo'))
+    assert_equal('', @filters.first(''))
+    assert_equal('', @filters.last(''))
+  end
+
+  def test_first_last_on_unicode_strings
+    # Unicode strings should return the first/last grapheme cluster (character),
+    # not the first/last byte. Ruby's String#[] handles this correctly with index 0/-1.
+    # This ensures international text works properly:
+    #   {{ korean_name | first }} => "고" (not a partial byte sequence)
+    assert_equal('고', @filters.first('고스트빈'))
+    assert_equal('빈', @filters.last('고스트빈'))
+  end
+
+  def test_first_last_on_strings_via_template
+    # Integration test to verify the filter works end-to-end in templates.
+    # Empty strings return empty output (nil renders as empty string).
+    assert_template_result('f', '{{ name | first }}', { 'name' => 'foo' })
+    assert_template_result('o', '{{ name | last }}', { 'name' => 'foo' })
+    assert_template_result('', '{{ name | first }}', { 'name' => '' })
+    assert_template_result('', '{{ name | last }}', { 'name' => '' })
+  end
+
   def test_replace
     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))
@@ -1302,7 +1330,7 @@ class StandardFiltersTest < Minitest::Test
     assert_equal(1, @filters.sum(input, true))
     assert_equal(0.2, @filters.sum(input, 1.0))
     assert_equal(-0.3, @filters.sum(input, 1))
-    assert_equal(0.4, @filters.sum(input, (1..5)))
+    assert_equal(0.4, @filters.sum(input, 1..5))
     assert_equal(0, @filters.sum(input, nil))
     assert_equal(0, @filters.sum(input, ""))
   end

test/integration/tags/cycle_tag_test.rb

@@ -91,28 +91,21 @@ class CycleTagTest < Minitest::Test
     assert_match(/Syntax Error in 'cycle' - Valid syntax: cycle \[name :\] var/, error.message)
   end
 
-  def test_cycle_tag_with_error_mode
+  def test_cycle_tag_unsupported_legacy_quirk
     # QuotedFragment is more permissive than what Parser#expression allows.
     template1 = "{% assign 5 = 'b' %}{% cycle .5, .4 %}"
     template2 = "{% cycle .5: 'a', 'b' %}"
 
-    with_error_modes(:lax, :strict) do
-      assert_template_result("b", template1)
-      assert_template_result("a", template2)
-    end
+    error1 = assert_raises(Liquid::SyntaxError) { Template.parse(template1) }
+    error2 = assert_raises(Liquid::SyntaxError) { Template.parse(template2) }
 
-    with_error_modes(:rigid) do
-      error1 = assert_raises(Liquid::SyntaxError) { Template.parse(template1) }
-      error2 = assert_raises(Liquid::SyntaxError) { Template.parse(template2) }
+    expected_error = /Liquid syntax error: \[:dot, "."\] is not a valid expression/
 
-      expected_error = /Liquid syntax error: \[:dot, "."\] is not a valid expression/
-
-      assert_match(expected_error, error1.message)
-      assert_match(expected_error, error2.message)
-    end
+    assert_match(expected_error, error1.message)
+    assert_match(expected_error, error2.message)
   end
 
-  def test_cycle_with_trailing_elements
+  def test_cycle_with_trailing_elements_legacy_syntax
     assignments = "{% assign a = 'A' %}{% assign n = 'N' %}"
 
     template1 = "#{assignments}{% cycle       'a'  'b', 'c' %}"
@@ -121,29 +114,19 @@ class CycleTagTest < Minitest::Test
     template4 = "#{assignments}{% cycle n  e: 'a', 'b', 'c' %}"
     template5 = "#{assignments}{% cycle n  e  'a', 'b', 'c' %}"
 
-    with_error_modes(:lax, :strict) do
-      assert_template_result("a", template1)
-      assert_template_result("a", template2)
-      assert_template_result("a", template3)
-      assert_template_result("N", template4)
-      assert_template_result("N", template5)
-    end
+    error1 = assert_raises(Liquid::SyntaxError) { Template.parse(template1) }
+    error2 = assert_raises(Liquid::SyntaxError) { Template.parse(template2) }
+    error3 = assert_raises(Liquid::SyntaxError) { Template.parse(template3) }
+    error4 = assert_raises(Liquid::SyntaxError) { Template.parse(template4) }
+    error5 = assert_raises(Liquid::SyntaxError) { Template.parse(template5) }
 
-    with_error_modes(:rigid) do
-      error1 = assert_raises(Liquid::SyntaxError) { Template.parse(template1) }
-      error2 = assert_raises(Liquid::SyntaxError) { Template.parse(template2) }
-      error3 = assert_raises(Liquid::SyntaxError) { Template.parse(template3) }
-      error4 = assert_raises(Liquid::SyntaxError) { Template.parse(template4) }
-      error5 = assert_raises(Liquid::SyntaxError) { Template.parse(template5) }
+    expected_error = /Expected end_of_string but found/
 
-      expected_error = /Expected end_of_string but found/
-
-      assert_match(expected_error, error1.message)
-      assert_match(expected_error, error2.message)
-      assert_match(expected_error, error3.message)
-      assert_match(expected_error, error4.message)
-      assert_match(expected_error, error5.message)
-    end
+    assert_match(expected_error, error1.message)
+    assert_match(expected_error, error2.message)
+    assert_match(expected_error, error3.message)
+    assert_match(expected_error, error4.message)
+    assert_match(expected_error, error5.message)
   end
 
   def test_cycle_name_with_invalid_expression
@@ -153,14 +136,8 @@ class CycleTagTest < Minitest::Test
       {% endfor %}
     LIQUID
 
-    with_error_modes(:lax, :strict) do
-      refute_nil(Template.parse(template))
-    end
-
-    with_error_modes(:rigid) do
-      error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
-      assert_match(/Unexpected character =/, error.message)
-    end
+    error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
+    assert_match(/Unexpected character =/, error.message)
   end
 
   def test_cycle_variable_with_invalid_expression
@@ -170,13 +147,7 @@ class CycleTagTest < Minitest::Test
       {% endfor %}
     LIQUID
 
-    with_error_modes(:lax, :strict) do
-      refute_nil(Template.parse(template))
-    end
-
-    with_error_modes(:rigid) do
-      error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
-      assert_match(/Unexpected character =/, error.message)
-    end
+    error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
+    assert_match(/Unexpected character =/, error.message)
   end
 end

test/integration/tags/include_tag_test.rb

@@ -204,23 +204,13 @@ class IncludeTagTest < Minitest::Test
     )
   end
 
-  def test_rigid_parsing_errors
-    with_error_modes(:lax, :strict) do
-      assert_template_result(
-        'hello value1 value2',
-        '{% include "snippet" !!! arg1: "value1" ~~~ arg2: "value2" %}',
-        partials: { 'snippet' => 'hello {{ arg1 }} {{ arg2 }}' },
-      )
-    end
-
-    with_error_modes(:rigid) do
-      assert_syntax_error(
-        '{% include "snippet" !!! arg1: "value1" ~~~ arg2: "value2" %}',
-      )
-      assert_syntax_error(
-        '{% include "snippet" | filter %}',
-      )
-    end
+  def test_parsing_errors_for_legacy_quirk
+    assert_syntax_error(
+      '{% include "snippet" !!! arg1: "value1" ~~~ arg2: "value2" %}',
+    )
+    assert_syntax_error(
+      '{% include "snippet" | filter %}',
+    )
   end
 
   def test_optional_commas
@@ -301,16 +291,10 @@ class IncludeTagTest < Minitest::Test
     env = Liquid::Environment.build(file_system: TestFileSystem.new)
 
     assert_raises(Liquid::SyntaxError) do
-      Template.parse("{% include template %}", error_mode: :strict, environment: env).render!("template" => '{{ "X" || downcase }}')
-    end
-    with_error_modes(:lax) do
-      assert_equal('x', Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: true, environment: env).render!("template" => '{{ "X" || downcase }}'))
+      Template.parse("{% include template %}", environment: env).render!("template" => '{{ "X" || downcase }}')
     end
     assert_raises(Liquid::SyntaxError) do
-      Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: [:locale], environment: env).render!("template" => '{{ "X" || downcase }}')
-    end
-    with_error_modes(:lax) do
-      assert_equal('x', Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: [:error_mode], environment: env).render!("template" => '{{ "X" || downcase }}'))
+      Template.parse("{% include template %}", include_options_blacklist: [:locale], environment: env).render!("template" => '{{ "X" || downcase }}')
     end
   end
 
@@ -365,7 +349,7 @@ class IncludeTagTest < Minitest::Test
       file_system: StubFileSystem.new('simple' => 'simple'),
     )
 
-    template = Liquid::Template.parse("{% include 'simple' %}", error_mode: :warn, environment: env)
+    template = Liquid::Template.parse("{% include 'simple' %}", environment: env)
     template.render(nil, strict_variables: true)
 
     assert_equal([], template.errors)
@@ -404,39 +388,21 @@ class IncludeTagTest < Minitest::Test
   def test_include_template_with_invalid_expression
     template = "{% include foo=>bar %}"
 
-    with_error_modes(:lax, :strict) do
-      refute_nil(Template.parse(template))
-    end
-
-    with_error_modes(:rigid) do
-      error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
-      assert_match(/Unexpected character =/, error.message)
-    end
+    error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
+    assert_match(/Unexpected character =/, error.message)
   end
 
   def test_include_with_invalid_expression
     template = '{% include "snippet" with foo=>bar %}'
 
-    with_error_modes(:lax, :strict) do
-      refute_nil(Template.parse(template))
-    end
-
-    with_error_modes(:rigid) do
-      error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
-      assert_match(/Unexpected character =/, error.message)
-    end
+    error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
+    assert_match(/Unexpected character =/, error.message)
   end
 
   def test_include_attribute_with_invalid_expression
     template = '{% include "snippet", key: foo=>bar %}'
 
-    with_error_modes(:lax, :strict) do
-      refute_nil(Template.parse(template))
-    end
-
-    with_error_modes(:rigid) do
-      error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
-      assert_match(/Unexpected character =/, error.message)
-    end
+    error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
+    assert_match(/Unexpected character =/, error.message)
   end
 end # IncludeTagTest

test/integration/tags/render_tag_test.rb

@@ -101,23 +101,17 @@ class RenderTagTest < Minitest::Test
     end
   end
 
-  def test_rigid_parsing_errors
-    with_error_modes(:lax, :strict) do
-      assert_template_result(
-        'hello value1 value2',
-        '{% render "snippet" !!! arg1: "value1" ~~~ arg2: "value2" %}',
-        partials: { 'snippet' => 'hello {{ arg1 }} {{ arg2 }}' },
-      )
-    end
+  def test_dynamically_choosen_templates_are_not_allowed
+    assert_syntax_error("{% assign name = 'snippet' %}{% render name %}")
+  end
 
-    with_error_modes(:rigid) do
-      assert_syntax_error(
-        '{% render "snippet" !!! arg1: "value1" ~~~ arg2: "value2" %}',
-      )
-      assert_syntax_error(
-        '{% render "snippet" | filter %}',
-      )
-    end
+  def test_parsing_errors_legacy_syntax
+    assert_syntax_error(
+      '{% render "snippet" !!! arg1: "value1" ~~~ arg2: "value2" %}',
+    )
+    assert_syntax_error(
+      '{% render "snippet" | filter %}',
+    )
   end
 
   def test_optional_commas
@@ -290,13 +284,6 @@ class RenderTagTest < Minitest::Test
     )
   end
 
-  def test_render_tag_with_snippet_drop
-    assert_template_result(
-      "Hello from snippet",
-      "{% snippet my_snippet %}Hello from snippet{% endsnippet %}{% render my_snippet %}",
-    )
-  end
-
   def test_render_tag_renders_error_with_template_name
     assert_template_result(
       'Liquid error (foo line 1): standard error',
@@ -320,27 +307,13 @@ class RenderTagTest < Minitest::Test
 
   def test_render_with_invalid_expression
     template = '{% render "snippet" with foo=>bar %}'
-
-    with_error_modes(:lax, :strict) do
-      refute_nil(Template.parse(template))
-    end
-
-    with_error_modes(:rigid) do
-      error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
-      assert_match(/Unexpected character =/, error.message)
-    end
+    error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
+    assert_match(/Unexpected character =/, error.message)
   end
 
   def test_render_attribute_with_invalid_expression
     template = '{% render "snippet", key: foo=>bar %}'
-
-    with_error_modes(:lax, :strict) do
-      refute_nil(Template.parse(template))
-    end
-
-    with_error_modes(:rigid) do
-      error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
-      assert_match(/Unexpected character =/, error.message)
-    end
+    error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
+    assert_match(/Unexpected character =/, error.message)
   end
 end

test/integration/tags/standard_tag_test.rb

@@ -117,7 +117,7 @@ class StandardTagTest < Minitest::Test
     assigns = { 'condition' => "bad string here" }
     assert_template_result(
       '',
-      '{% case condition %}{% when "string here" %} hit {% endcase %}',\
+      '{% case condition %}{% when "string here" %} hit {% endcase %}',
       assigns,
     )
   end

test/integration/tags/table_row_test.rb

@@ -188,29 +188,6 @@ class TableRowTest < Minitest::Test
     assert_template_result(expected_output, template)
   end
 
-  def test_table_row_renders_correct_error_message_for_invalid_parameters
-    assert_template_result(
-      "Liquid error (line 1): invalid integer",
-      '{% tablerow n in (1...10) limit:true %} {{n}} {% endtablerow %}',
-      error_mode: :warn,
-      render_errors: true,
-    )
-
-    assert_template_result(
-      "Liquid error (line 1): invalid integer",
-      '{% tablerow n in (1...10) offset:true %} {{n}} {% endtablerow %}',
-      error_mode: :warn,
-      render_errors: true,
-    )
-
-    assert_template_result(
-      "Liquid error (line 1): invalid integer",
-      '{% tablerow n in (1...10) cols:true %} {{n}} {% endtablerow %}',
-      render_errors: true,
-      error_mode: :warn,
-    )
-  end
-
   def test_table_row_handles_interrupts
     assert_template_result(
       "<tr class=\"row1\">\n<td class=\"col1\"> 1 </td></tr>\n",
@@ -259,7 +236,7 @@ class TableRowTest < Minitest::Test
     )
   end
 
-  def test_tablerow_with_cols_attribute_in_rigid_mode
+  def test_tablerow_with_cols_attribute
     template = <<~LIQUID.chomp
       {% tablerow i in (1..6) cols: 3 %}{{ i }}{% endtablerow %}
     LIQUID
@@ -270,12 +247,10 @@ class TableRowTest < Minitest::Test
       <tr class="row2"><td class="col1">4</td><td class="col2">5</td><td class="col3">6</td></tr>
     OUTPUT
 
-    with_error_modes(:rigid) do
-      assert_template_result(expected, template)
-    end
+    assert_template_result(expected, template)
   end
 
-  def test_tablerow_with_limit_attribute_in_rigid_mode
+  def test_tablerow_with_limit_attribute
     template = <<~LIQUID.chomp
       {% tablerow i in (1..10) limit: 3 %}{{ i }}{% endtablerow %}
     LIQUID
@@ -285,12 +260,10 @@ class TableRowTest < Minitest::Test
       <td class="col1">1</td><td class="col2">2</td><td class="col3">3</td></tr>
     OUTPUT
 
-    with_error_modes(:rigid) do
-      assert_template_result(expected, template)
-    end
+    assert_template_result(expected, template)
   end
 
-  def test_tablerow_with_offset_attribute_in_rigid_mode
+  def test_tablerow_with_offset_attribute
     template = <<~LIQUID.chomp
       {% tablerow i in (1..5) offset: 2 %}{{ i }}{% endtablerow %}
     LIQUID
@@ -300,12 +273,10 @@ class TableRowTest < Minitest::Test
       <td class="col1">3</td><td class="col2">4</td><td class="col3">5</td></tr>
     OUTPUT
 
-    with_error_modes(:rigid) do
-      assert_template_result(expected, template)
-    end
+    assert_template_result(expected, template)
   end
 
-  def test_tablerow_with_range_attribute_in_rigid_mode
+  def test_tablerow_with_range_attribute
     template = <<~LIQUID.chomp
       {% tablerow i in (1..3) range: (1..10) %}{{ i }}{% endtablerow %}
     LIQUID
@@ -315,12 +286,10 @@ class TableRowTest < Minitest::Test
       <td class="col1">1</td><td class="col2">2</td><td class="col3">3</td></tr>
     OUTPUT
 
-    with_error_modes(:rigid) do
-      assert_template_result(expected, template)
-    end
+    assert_template_result(expected, template)
   end
 
-  def test_tablerow_with_multiple_attributes_in_rigid_mode
+  def test_tablerow_with_multiple_attributes
     template = <<~LIQUID.chomp
       {% tablerow i in (1..10) cols: 2, limit: 4, offset: 1 %}{{ i }}{% endtablerow %}
     LIQUID
@@ -331,12 +300,10 @@ class TableRowTest < Minitest::Test
       <tr class="row2"><td class="col1">4</td><td class="col2">5</td></tr>
     OUTPUT
 
-    with_error_modes(:rigid) do
-      assert_template_result(expected, template)
-    end
+    assert_template_result(expected, template)
   end
 
-  def test_tablerow_with_variable_collection_in_rigid_mode
+  def test_tablerow_with_variable_collection
     template = <<~LIQUID.chomp
       {% tablerow n in numbers cols: 2 %}{{ n }}{% endtablerow %}
     LIQUID
@@ -347,12 +314,10 @@ class TableRowTest < Minitest::Test
       <tr class="row2"><td class="col1">3</td><td class="col2">4</td></tr>
     OUTPUT
 
-    with_error_modes(:rigid) do
-      assert_template_result(expected, template, { 'numbers' => [1, 2, 3, 4] })
-    end
+    assert_template_result(expected, template, { 'numbers' => [1, 2, 3, 4] })
   end
 
-  def test_tablerow_with_dotted_access_in_rigid_mode
+  def test_tablerow_with_dotted_access
     template = <<~LIQUID.chomp
       {% tablerow n in obj.numbers cols: 2 %}{{ n }}{% endtablerow %}
     LIQUID
@@ -363,12 +328,10 @@ class TableRowTest < Minitest::Test
       <tr class="row2"><td class="col1">3</td><td class="col2">4</td></tr>
     OUTPUT
 
-    with_error_modes(:rigid) do
-      assert_template_result(expected, template, { 'obj' => { 'numbers' => [1, 2, 3, 4] } })
-    end
+    assert_template_result(expected, template, { 'obj' => { 'numbers' => [1, 2, 3, 4] } })
   end
 
-  def test_tablerow_with_bracketed_access_in_rigid_mode
+  def test_tablerow_with_bracketed_access
     template = <<~LIQUID.chomp
       {% tablerow n in obj["numbers"] cols: 2 %}{{ n }}{% endtablerow %}
     LIQUID
@@ -378,12 +341,10 @@ class TableRowTest < Minitest::Test
       <td class="col1">10</td><td class="col2">20</td></tr>
     OUTPUT
 
-    with_error_modes(:rigid) do
-      assert_template_result(expected, template, { 'obj' => { 'numbers' => [10, 20] } })
-    end
+    assert_template_result(expected, template, { 'obj' => { 'numbers' => [10, 20] } })
   end
 
-  def test_tablerow_without_attributes_in_rigid_mode
+  def test_tablerow_without_attributes
     template = <<~LIQUID.chomp
       {% tablerow i in (1..3) %}{{ i }}{% endtablerow %}
     LIQUID
@@ -393,30 +354,24 @@ class TableRowTest < Minitest::Test
       <td class="col1">1</td><td class="col2">2</td><td class="col3">3</td></tr>
     OUTPUT
 
-    with_error_modes(:rigid) do
-      assert_template_result(expected, template)
-    end
+    assert_template_result(expected, template)
   end
 
-  def test_tablerow_without_in_keyword_in_rigid_mode
+  def test_tablerow_without_in_keyword
     template = '{% tablerow i (1..10) %}{{ i }}{% endtablerow %}'
 
-    with_error_modes(:rigid) do
-      error = assert_raises(SyntaxError) { Template.parse(template) }
-      assert_equal("Liquid syntax error: For loops require an 'in' clause in \"i (1..10)\"", error.message)
-    end
+    error = assert_raises(SyntaxError) { Template.parse(template) }
+    assert_equal("Liquid syntax error: For loops require an 'in' clause in \"i (1..10)\"", error.message)
   end
 
-  def test_tablerow_with_multiple_invalid_attributes_reports_first_in_rigid_mode
+  def test_tablerow_with_multiple_invalid_attributes_reports_first
     template = '{% tablerow i in (1..10) invalid1: 5, invalid2: 10 %}{{ i }}{% endtablerow %}'
 
-    with_error_modes(:rigid) do
-      error = assert_raises(SyntaxError) { Template.parse(template) }
-      assert_equal("Liquid syntax error: Invalid attribute 'invalid1' in tablerow loop. Valid attributes are cols, limit, offset, and range in \"i in (1..10) invalid1: 5, invalid2: 10\"", error.message)
-    end
+    error = assert_raises(SyntaxError) { Template.parse(template) }
+    assert_equal("Liquid syntax error: Invalid attribute 'invalid1' in tablerow loop. Valid attributes are cols, limit, offset, and range in \"i in (1..10) invalid1: 5, invalid2: 10\"", error.message)
   end
 
-  def test_tablerow_with_empty_collection_in_rigid_mode
+  def test_tablerow_with_empty_collection
     template = <<~LIQUID.chomp
       {% tablerow i in empty_array cols: 2 %}{{ i }}{% endtablerow %}
     LIQUID
@@ -426,43 +381,18 @@ class TableRowTest < Minitest::Test
       </tr>
     OUTPUT
 
-    with_error_modes(:rigid) do
-      assert_template_result(expected, template, { 'empty_array' => [] })
-    end
+    assert_template_result(expected, template, { 'empty_array' => [] })
   end
 
-  def test_tablerow_with_invalid_attribute_strict_vs_rigid
+  def test_tablerow_with_invalid_attribute
     template = '{% tablerow i in (1..5) invalid_attr: 10 %}{{ i }}{% endtablerow %}'
-
-    expected = <<~OUTPUT
-      <tr class="row1">
-      <td class="col1">1</td><td class="col2">2</td><td class="col3">3</td><td class="col4">4</td><td class="col5">5</td></tr>
-    OUTPUT
-
-    with_error_modes(:lax, :strict) do
-      assert_template_result(expected, template)
-    end
-
-    with_error_modes(:rigid) do
-      error = assert_raises(SyntaxError) { Template.parse(template) }
-      assert_match(/Invalid attribute 'invalid_attr'/, error.message)
-    end
+    error = assert_raises(SyntaxError) { Template.parse(template) }
+    assert_match(/Invalid attribute 'invalid_attr'/, error.message)
   end
 
-  def test_tablerow_with_invalid_expression_strict_vs_rigid
+  def test_tablerow_with_invalid_expression
     template = '{% tablerow i in (1..5) limit: foo=>bar %}{{ i }}{% endtablerow %}'
-
-    with_error_modes(:lax, :strict) do
-      expected = <<~OUTPUT
-        <tr class="row1">
-        </tr>
-      OUTPUT
-      assert_template_result(expected, template)
-    end
-
-    with_error_modes(:rigid) do
-      error = assert_raises(SyntaxError) { Template.parse(template) }
-      assert_match(/Unexpected character =/, error.message)
-    end
+    error = assert_raises(SyntaxError) { Template.parse(template) }
+    assert_match(/Unexpected character =/, error.message)
   end
 end

test/integration/template_test.rb

@@ -44,16 +44,6 @@ class TemplateTest < Minitest::Test
     assert_equal('from instance assigns', t.parse("{{ foo }}").render!)
   end
 
-  def test_warnings_is_not_exponential_time
-    str = "false"
-    100.times do
-      str = "{% if true %}true{% else %}#{str}{% endif %}"
-    end
-
-    t = Template.parse(str)
-    assert_equal([], Timeout.timeout(1) { t.warnings })
-  end
-
   def test_instance_assigns_persist_on_same_template_parsing_between_renders
     t = Template.new.parse("{{ foo }}{% assign foo = 'foo' %}{{ foo }}")
     assert_equal('foo', t.render!)
@@ -133,7 +123,7 @@ class TemplateTest < Minitest::Test
     assert(t.resource_limits.reached?)
 
     t.resource_limits.render_score_limit = 200
-    assert_equal((" foo " * 100), t.render!)
+    assert_equal(" foo " * 100, t.render!)
     refute_nil(t.resource_limits.render_score)
   end
 
@@ -259,7 +249,7 @@ class TemplateTest < Minitest::Test
   end
 
   def test_nil_value_does_not_raise
-    t      = Template.parse("some{{x}}thing", error_mode: :strict)
+    t      = Template.parse("some{{x}}thing")
     result = t.render!({ 'x' => nil }, strict_variables: true)
 
     assert_equal(0, t.errors.count)

test/integration/variable_test.rb

@@ -176,102 +176,33 @@ class VariableTest < Minitest::Test
     )
   end
 
-  def test_variable_lookup_should_not_hang_with_invalid_syntax
-    Timeout.timeout(1) do
-      assert_template_result(
-        'bar',
-        "{{['foo'}}",
-        {
-          'foo' => 'bar',
-        },
-        error_mode: :lax,
-      )
-    end
-
-    very_long_key = "1234567890" * 100
-
-    template_list = [
-      "{{['#{very_long_key}']}}", # valid
-      "{{['#{very_long_key}'}}", # missing closing bracket
-      "{{[['#{very_long_key}']}}", # extra open bracket
-    ]
-
-    template_list.each do |template|
-      Timeout.timeout(1) do
-        assert_template_result(
-          'bar',
-          template,
-          {
-            very_long_key => 'bar',
-          },
-          error_mode: :lax,
-        )
-      end
-    end
-  end
-
   def test_filter_with_single_trailing_comma
     template = '{{ "hello" | append: "world", }}'
 
-    with_error_modes(:strict) do
-      error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
-      assert_match(/is not a valid expression/, error.message)
-    end
-
-    with_error_modes(:rigid) do
-      assert_template_result('helloworld', template)
-    end
+    assert_template_result('helloworld', template)
   end
 
   def test_multiple_filters_with_trailing_commas
     template = '{{ "hello" | append: "1", | append: "2", }}'
 
-    with_error_modes(:strict) do
-      error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
-      assert_match(/is not a valid expression/, error.message)
-    end
-
-    with_error_modes(:rigid) do
-      assert_template_result('hello12', template)
-    end
+    assert_template_result('hello12', template)
   end
 
   def test_filter_with_colon_but_no_arguments
     template = '{{ "test" | upcase: }}'
 
-    with_error_modes(:strict) do
-      error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
-      assert_match(/is not a valid expression/, error.message)
-    end
-
-    with_error_modes(:rigid) do
-      assert_template_result('TEST', template)
-    end
+    assert_template_result('TEST', template)
   end
 
   def test_filter_chain_with_colon_no_args
     template = '{{ "test" | append: "x" | upcase: }}'
 
-    with_error_modes(:strict) do
-      error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
-      assert_match(/is not a valid expression/, error.message)
-    end
-
-    with_error_modes(:rigid) do
-      assert_template_result('TESTX', template)
-    end
+    assert_template_result('TESTX', template)
   end
 
   def test_combining_trailing_comma_and_empty_args
     template = '{{ "test" | append: "x", | upcase: }}'
 
-    with_error_modes(:strict) do
-      error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
-      assert_match(/is not a valid expression/, error.message)
-    end
-
-    with_error_modes(:rigid) do
-      assert_template_result('TESTX', template)
-    end
+    assert_template_result('TESTX', template)
   end
 end

test/test_helper.rb

@@ -8,13 +8,6 @@ $LOAD_PATH.unshift(File.join(File.expand_path(__dir__), '..', 'lib'))
 require 'liquid.rb'
 require 'liquid/profiler'
 
-mode = :strict
-if (env_mode = ENV['LIQUID_PARSER_MODE'])
-  puts "-- #{env_mode.upcase} ERROR MODE"
-  mode = env_mode.to_sym
-end
-Liquid::Environment.default.error_mode = mode
-
 if Minitest.const_defined?('Test')
   # We're on Minitest 5+. Nothing to do here.
 else
@@ -34,27 +27,27 @@ module Minitest
 
     def assert_template_result(
       expected, template, assigns = {},
-      message: nil, partials: nil, error_mode: Liquid::Environment.default.error_mode, render_errors: false,
+      message: nil, partials: nil, render_errors: false,
       template_factory: nil
     )
       file_system = StubFileSystem.new(partials || {})
       environment = Liquid::Environment.build(file_system: file_system)
-      template = Liquid::Template.parse(template, line_numbers: true, error_mode: error_mode&.to_sym, environment: environment)
+      template = Liquid::Template.parse(template, line_numbers: true, environment: environment)
       registers = Liquid::Registers.new(file_system: file_system, template_factory: template_factory)
       context = Liquid::Context.build(static_environments: assigns, rethrow_errors: !render_errors, registers: registers, environment: environment)
       output = template.render(context)
       assert_equal(expected, output, message)
     end
 
-    def assert_match_syntax_error(match, template, error_mode: nil)
+    def assert_match_syntax_error(match, template)
       exception = assert_raises(Liquid::SyntaxError) do
-        Template.parse(template, line_numbers: true, error_mode: error_mode&.to_sym).render
+        Template.parse(template, line_numbers: true).render
       end
       assert_match(match, exception.message)
     end
 
-    def assert_syntax_error(template, error_mode: nil)
-      assert_match_syntax_error("", template, error_mode: error_mode)
+    def assert_syntax_error(template)
+      assert_match_syntax_error("", template)
     end
 
     def assert_usage_increment(name, times: 1)
@@ -82,16 +75,6 @@ module Minitest
       Environment.dangerously_override(environment, &blk)
     end
 
-    def with_error_modes(*modes)
-      old_mode = Liquid::Environment.default.error_mode
-      modes.each do |mode|
-        Liquid::Environment.default.error_mode = mode
-        yield
-      end
-    ensure
-      Liquid::Environment.default.error_mode = old_mode
-    end
-
     def with_custom_tag(tag_name, tag_class, &block)
       environment = Liquid::Environment.default.dup
       environment.register_tag(tag_name, tag_class)
@@ -199,6 +182,26 @@ class ErrorDrop < Liquid::Drop
   end
 end
 
+class CustomToLiquidDrop < Liquid::Drop
+  def initialize(value)
+    @value = value
+    super()
+  end
+
+  def to_liquid
+    @value
+  end
+end
+
+class HashWithCustomToS < Hash
+  def to_s
+    "kewl"
+  end
+end
+
+class HashWithoutCustomToS < Hash
+end
+
 class StubFileSystem
   attr_reader :file_read_count
 

test/unit/condition_unit_test.rb

@@ -161,34 +161,13 @@ class ConditionUnitTest < Minitest::Test
       assert_equal(true, Condition.new(1, '==', 1).evaluate)
     end
 
-    expected = "DEPRECATION WARNING: Condition#evaluate without a context argument is deprecated" \
-      " and will be removed from Liquid 6.0.0."
+    expected = "DEPRECATION WARNING: Condition#evaluate without a context argument is deprecated " \
+      "and will be removed from Liquid 6.0.0."
     assert_includes(err.lines.map(&:strip), expected)
   end
 
-  def test_parse_expression_in_strict_mode
-    environment = Environment.build(error_mode: :strict)
-    parse_context = ParseContext.new(environment: environment)
-    result = Condition.parse_expression(parse_context, 'product.title')
-
-    assert_instance_of(VariableLookup, result)
-    assert_equal('product', result.name)
-    assert_equal(['title'], result.lookups)
-  end
-
-  def test_parse_expression_in_rigid_mode_raises_internal_error
-    environment = Environment.build(error_mode: :rigid)
-    parse_context = ParseContext.new(environment: environment)
-
-    error = assert_raises(Liquid::InternalError) do
-      Condition.parse_expression(parse_context, 'product.title')
-    end
-
-    assert_match(/unsafe parse_expression cannot be used in rigid mode/, error.message)
-  end
-
-  def test_parse_expression_with_safe_true_in_rigid_mode
-    environment = Environment.build(error_mode: :rigid)
+  def test_parse_expression_with_safe_true
+    environment = Environment.build
     parse_context = ParseContext.new(environment: environment)
     result = Condition.parse_expression(parse_context, 'product.title', safe: true)
 
@@ -197,6 +176,183 @@ class ConditionUnitTest < Minitest::Test
     assert_equal(['title'], result.lookups)
   end
 
+  def test_parse_expression_raises_internal_error_if_not_safe
+    environment = Environment.build
+    parse_context = ParseContext.new(environment: environment)
+
+    error = assert_raises(Liquid::InternalError) do
+      Condition.parse_expression(parse_context, 'product.title')
+    end
+
+    assert_match(/unsafe parse_expression cannot be used/, error.message)
+  end
+
+  # Tests for blank? comparison without ActiveSupport
+  #
+  # Ruby's standard library does not include blank? on String, Array, Hash, etc.
+  # ActiveSupport adds blank? but Liquid must work without it. These tests verify
+  # that Liquid implements blank? semantics internally for use in templates like:
+  #   {% if x == blank %}...{% endif %}
+  #
+  # The blank? semantics match ActiveSupport's behavior:
+  # - nil and false are blank
+  # - Strings are blank if empty or contain only whitespace
+  # - Arrays and Hashes are blank if empty
+  # - true and numbers are never blank
+
+  def test_blank_with_whitespace_string
+    # Template authors expect "   " to be blank since it has no visible content.
+    # This matches ActiveSupport's String#blank? which returns true for whitespace-only strings.
+    @context['whitespace'] = '   '
+    blank_literal = Condition.class_variable_get(:@@method_literals)['blank']
+
+    assert_evaluates_true(VariableLookup.new('whitespace'), '==', blank_literal)
+  end
+
+  def test_blank_with_empty_string
+    # An empty string has no content, so it should be considered blank.
+    # This is the most basic case of a blank string.
+    @context['empty_string'] = ''
+    blank_literal = Condition.class_variable_get(:@@method_literals)['blank']
+
+    assert_evaluates_true(VariableLookup.new('empty_string'), '==', blank_literal)
+  end
+
+  def test_blank_with_empty_array
+    # Empty arrays have no elements, so they are blank.
+    # Useful for checking if a collection has items: {% if products == blank %}
+    @context['empty_array'] = []
+    blank_literal = Condition.class_variable_get(:@@method_literals)['blank']
+
+    assert_evaluates_true(VariableLookup.new('empty_array'), '==', blank_literal)
+  end
+
+  def test_blank_with_empty_hash
+    # Empty hashes have no key-value pairs, so they are blank.
+    # Useful for checking if settings/options exist: {% if settings == blank %}
+    @context['empty_hash'] = {}
+    blank_literal = Condition.class_variable_get(:@@method_literals)['blank']
+
+    assert_evaluates_true(VariableLookup.new('empty_hash'), '==', blank_literal)
+  end
+
+  def test_blank_with_nil
+    # nil represents "nothing" and is the canonical blank value.
+    # Unassigned variables resolve to nil, so this enables: {% if missing_var == blank %}
+    @context['nil_value'] = nil
+    blank_literal = Condition.class_variable_get(:@@method_literals)['blank']
+
+    assert_evaluates_true(VariableLookup.new('nil_value'), '==', blank_literal)
+  end
+
+  def test_blank_with_false
+    # false is considered blank to match ActiveSupport semantics.
+    # This allows {% if some_flag == blank %} to work when flag is false.
+    @context['false_value'] = false
+    blank_literal = Condition.class_variable_get(:@@method_literals)['blank']
+
+    assert_evaluates_true(VariableLookup.new('false_value'), '==', blank_literal)
+  end
+
+  def test_not_blank_with_true
+    # true is a definite value, not blank.
+    # Ensures {% if flag == blank %} works correctly for boolean flags.
+    @context['true_value'] = true
+    blank_literal = Condition.class_variable_get(:@@method_literals)['blank']
+
+    assert_evaluates_false(VariableLookup.new('true_value'), '==', blank_literal)
+  end
+
+  def test_not_blank_with_number
+    # Numbers (including zero) are never blank - they represent actual values.
+    # 0 is a valid quantity, not the absence of a value.
+    @context['number'] = 42
+    blank_literal = Condition.class_variable_get(:@@method_literals)['blank']
+
+    assert_evaluates_false(VariableLookup.new('number'), '==', blank_literal)
+  end
+
+  def test_not_blank_with_string_content
+    # A string with actual content is not blank.
+    # This is the expected behavior for most template string comparisons.
+    @context['string'] = 'hello'
+    blank_literal = Condition.class_variable_get(:@@method_literals)['blank']
+
+    assert_evaluates_false(VariableLookup.new('string'), '==', blank_literal)
+  end
+
+  def test_not_blank_with_non_empty_array
+    # An array with elements has content, so it's not blank.
+    # Enables patterns like {% unless products == blank %}Show products{% endunless %}
+    @context['array'] = [1, 2, 3]
+    blank_literal = Condition.class_variable_get(:@@method_literals)['blank']
+
+    assert_evaluates_false(VariableLookup.new('array'), '==', blank_literal)
+  end
+
+  def test_not_blank_with_non_empty_hash
+    # A hash with key-value pairs has content, so it's not blank.
+    # Useful for checking if configuration exists: {% if config != blank %}
+    @context['hash'] = { 'a' => 1 }
+    blank_literal = Condition.class_variable_get(:@@method_literals)['blank']
+
+    assert_evaluates_false(VariableLookup.new('hash'), '==', blank_literal)
+  end
+
+  # Tests for empty? comparison without ActiveSupport
+  #
+  # empty? is distinct from blank? - it only checks if a collection has zero elements.
+  # For strings, empty? checks length == 0, NOT whitespace content.
+  # Ruby's standard library has empty? on String, Array, and Hash, but Liquid
+  # provides a fallback implementation for consistency.
+
+  def test_empty_with_empty_string
+    # An empty string ("") has length 0, so it's empty.
+    # Different from blank - empty is a stricter check.
+    @context['empty_string'] = ''
+    empty_literal = Condition.class_variable_get(:@@method_literals)['empty']
+
+    assert_evaluates_true(VariableLookup.new('empty_string'), '==', empty_literal)
+  end
+
+  def test_empty_with_whitespace_string_not_empty
+    # Whitespace strings have length > 0, so they are NOT empty.
+    # This is the key difference between empty and blank:
+    # "   ".empty? => false, but "   ".blank? => true
+    @context['whitespace'] = '   '
+    empty_literal = Condition.class_variable_get(:@@method_literals)['empty']
+
+    assert_evaluates_false(VariableLookup.new('whitespace'), '==', empty_literal)
+  end
+
+  def test_empty_with_empty_array
+    # An array with no elements is empty.
+    # [].empty? => true
+    @context['empty_array'] = []
+    empty_literal = Condition.class_variable_get(:@@method_literals)['empty']
+
+    assert_evaluates_true(VariableLookup.new('empty_array'), '==', empty_literal)
+  end
+
+  def test_empty_with_empty_hash
+    # A hash with no key-value pairs is empty.
+    # {}.empty? => true
+    @context['empty_hash'] = {}
+    empty_literal = Condition.class_variable_get(:@@method_literals)['empty']
+
+    assert_evaluates_true(VariableLookup.new('empty_hash'), '==', empty_literal)
+  end
+
+  def test_nil_is_not_empty
+    # nil is NOT empty - empty? checks if a collection has zero elements.
+    # nil is not a collection, so it cannot be empty.
+    # This differs from blank: nil IS blank, but nil is NOT empty.
+    @context['nil_value'] = nil
+    empty_literal = Condition.class_variable_get(:@@method_literals)['empty']
+
+    assert_evaluates_false(VariableLookup.new('nil_value'), '==', empty_literal)
+  end
+
   private
 
   def assert_evaluates_true(left, op, right)

test/unit/parse_context_unit_test.rb

@@ -6,118 +6,81 @@ class ParseContextUnitTest < Minitest::Test
   include Liquid
 
   def test_safe_parse_expression_with_variable_lookup
-    parser_strict = strict_parse_context.new_parser('product.title')
-    result_strict = strict_parse_context.safe_parse_expression(parser_strict)
+    parser = parse_context.new_parser('product.title')
+    result = parse_context.safe_parse_expression(parser)
 
-    parser_rigid = rigid_parse_context.new_parser('product.title')
-    result_rigid = rigid_parse_context.safe_parse_expression(parser_rigid)
-
-    assert_instance_of(VariableLookup, result_strict)
-    assert_equal('product', result_strict.name)
-    assert_equal(['title'], result_strict.lookups)
-
-    assert_instance_of(VariableLookup, result_rigid)
-    assert_equal('product', result_rigid.name)
-    assert_equal(['title'], result_rigid.lookups)
+    assert_instance_of(VariableLookup, result)
+    assert_equal('product', result.name)
+    assert_equal(['title'], result.lookups)
   end
 
   def test_safe_parse_expression_raises_syntax_error_for_invalid_expression
-    parser_strict = strict_parse_context.new_parser('')
-    parser_rigid = rigid_parse_context.new_parser('')
+    parser = parse_context.new_parser('')
 
-    error_strict = assert_raises(Liquid::SyntaxError) do
-      strict_parse_context.safe_parse_expression(parser_strict)
-    end
-    assert_match(/is not a valid expression/, error_strict.message)
-
-    error_rigid = assert_raises(Liquid::SyntaxError) do
-      rigid_parse_context.safe_parse_expression(parser_rigid)
+    error = assert_raises(Liquid::SyntaxError) do
+      parse_context.safe_parse_expression(parser)
     end
 
-    assert_match(/is not a valid expression/, error_rigid.message)
+    assert_match(/is not a valid expression/, error.message)
   end
 
   def test_parse_expression_with_variable_lookup
-    result_strict = strict_parse_context.parse_expression('product.title')
-
-    assert_instance_of(VariableLookup, result_strict)
-    assert_equal('product', result_strict.name)
-    assert_equal(['title'], result_strict.lookups)
-
     error = assert_raises(Liquid::InternalError) do
-      rigid_parse_context.parse_expression('product.title')
+      parse_context.parse_expression('product.title')
     end
 
-    assert_match(/unsafe parse_expression cannot be used in rigid mode/, error.message)
+    assert_match(/unsafe parse_expression cannot be used/, error.message)
   end
 
   def test_parse_expression_with_safe_true
-    result_strict = strict_parse_context.parse_expression('product.title', safe: true)
+    result = parse_context.parse_expression('product.title', safe: true)
 
-    assert_instance_of(VariableLookup, result_strict)
-    assert_equal('product', result_strict.name)
-    assert_equal(['title'], result_strict.lookups)
-
-    result_rigid = rigid_parse_context.parse_expression('product.title', safe: true)
-
-    assert_instance_of(VariableLookup, result_rigid)
-    assert_equal('product', result_rigid.name)
-    assert_equal(['title'], result_rigid.lookups)
+    assert_instance_of(VariableLookup, result)
+    assert_equal('product', result.name)
+    assert_equal(['title'], result.lookups)
   end
 
   def test_parse_expression_with_empty_string
-    result_strict = strict_parse_context.parse_expression('')
-    assert_nil(result_strict)
-
     error = assert_raises(Liquid::InternalError) do
-      rigid_parse_context.parse_expression('')
+      parse_context.parse_expression('')
     end
 
-    assert_match(/unsafe parse_expression cannot be used in rigid mode/, error.message)
+    assert_match(/unsafe parse_expression cannot be used/, error.message)
   end
 
   def test_parse_expression_with_empty_string_and_safe_true
-    result_strict = strict_parse_context.parse_expression('', safe: true)
-    assert_nil(result_strict)
-
-    result_rigid = rigid_parse_context.parse_expression('', safe: true)
-    assert_nil(result_rigid)
+    result = parse_context.parse_expression('', safe: true)
+    assert_nil(result)
   end
 
   def test_safe_parse_expression_advances_parser_pointer
-    parser = rigid_parse_context.new_parser('foo, bar')
+    parser = parse_context.new_parser('foo, bar')
 
     # safe_parse_expression consumes "foo"
-    first_result = rigid_parse_context.safe_parse_expression(parser)
+    first_result = parse_context.safe_parse_expression(parser)
     assert_instance_of(VariableLookup, first_result)
     assert_equal('foo', first_result.name)
 
     parser.consume(:comma)
 
     # safe_parse_expression consumes "bar"
-    second_result = rigid_parse_context.safe_parse_expression(parser)
+    second_result = parse_context.safe_parse_expression(parser)
     assert_instance_of(VariableLookup, second_result)
     assert_equal('bar', second_result.name)
 
     parser.consume(:end_of_string)
   end
 
-  def test_parse_expression_with_whitespace_in_rigid_mode
-    result = rigid_parse_context.parse_expression('   ', safe: true)
+  def test_parse_expression_with_whitespace
+    result = parse_context.parse_expression('   ', safe: true)
     assert_nil(result)
   end
 
   private
 
-  def strict_parse_context
-    @strict_parse_context ||= ParseContext.new(
-      environment: Environment.build(error_mode: :strict),
-    )
-  end
-
-  def rigid_parse_context
-    @rigid_parse_context ||= ParseContext.new(
-      environment: Environment.build(error_mode: :rigid),
+  def parse_context
+    @parse_context ||= ParseContext.new(
+      environment: Environment.build,
     )
   end
 end

test/unit/partial_cache_unit_test.rb

@@ -175,7 +175,7 @@ class PartialCacheUnitTest < Minitest::Test
     assert_equal('some/path/my_partial', partial.name)
   end
 
-  def test_includes_error_mode_into_template_cache
+  def test_cache_key
     template_factory = StubTemplateFactory.new
     context = Liquid::Context.build(
       registers: {
@@ -184,16 +184,14 @@ class PartialCacheUnitTest < Minitest::Test
       },
     )
 
-    [:lax, :warn, :strict, :rigid].each do |error_mode|
-      Liquid::PartialCache.load(
-        'my_partial',
-        context: context,
-        parse_context: Liquid::ParseContext.new(error_mode: error_mode),
-      )
-    end
+    Liquid::PartialCache.load(
+      'my_partial',
+      context: context,
+      parse_context: Liquid::ParseContext.new,
+    )
 
     assert_equal(
-      ["my_partial:lax", "my_partial:warn", "my_partial:strict", "my_partial:rigid"],
+      ["my_partial"],
       context.registers[:cached_partials].keys,
     )
   end

test/unit/strainer_template_unit_test.rb

@@ -8,7 +8,7 @@ class StrainerTemplateUnitTest < Minitest::Test
   def test_add_filter_when_wrong_filter_class
     c = Context.new
     s = c.strainer
-    wrong_filter = ->(v) { v.reverse }
+    wrong_filter = lambda(&:reverse)
 
     exception = assert_raises(TypeError) do
       s.class.add_filter(wrong_filter)

test/unit/tags/case_tag_unit_test.rb

@@ -20,15 +20,9 @@ class CaseTagUnitTest < Minitest::Test
       {%- endcase -%}
     LIQUID
 
-    with_error_modes(:lax, :strict) do
-      assert_template_result("one", template)
-    end
+    error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
 
-    with_error_modes(:rigid) do
-      error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
-
-      assert_match(/Expected end_of_string but found/, error.message)
-    end
+    assert_match(/Expected end_of_string but found/, error.message)
   end
 
   def test_case_when_with_trailing_element
@@ -41,15 +35,9 @@ class CaseTagUnitTest < Minitest::Test
       {%- endcase -%}
     LIQUID
 
-    with_error_modes(:lax, :strict) do
-      assert_template_result("one", template)
-    end
+    error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
 
-    with_error_modes(:rigid) do
-      error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
-
-      assert_match(/Expected end_of_string but found/, error.message)
-    end
+    assert_match(/Expected end_of_string but found/, error.message)
   end
 
   def test_case_when_with_comma
@@ -62,9 +50,7 @@ class CaseTagUnitTest < Minitest::Test
       {%- endcase -%}
     LIQUID
 
-    with_error_modes(:lax, :strict, :rigid) do
-      assert_template_result("one", template)
-    end
+    assert_template_result("one", template)
   end
 
   def test_case_when_with_or
@@ -77,9 +63,25 @@ class CaseTagUnitTest < Minitest::Test
       {%- endcase -%}
     LIQUID
 
-    with_error_modes(:lax, :strict, :rigid) do
-      assert_template_result("one", template)
-    end
+    assert_template_result("one", template)
+  end
+
+  def test_case_when_empty
+    template = <<~LIQUID
+      {%- case x -%}
+        {%- when 2 or empty -%}
+          2 or empty
+        {%- else -%}
+          not 2 or empty
+      {%- endcase -%}
+    LIQUID
+
+    assert_template_result("2 or empty", template, { 'x' => 2 })
+    assert_template_result("2 or empty", template, { 'x' => {} })
+    assert_template_result("2 or empty", template, { 'x' => [] })
+    assert_template_result("not 2 or empty", template, { 'x' => { 'a' => 'b' } })
+    assert_template_result("not 2 or empty", template, { 'x' => ['a'] })
+    assert_template_result("not 2 or empty", template, { 'x' => 4 })
   end
 
   def test_case_with_invalid_expression
@@ -93,15 +95,9 @@ class CaseTagUnitTest < Minitest::Test
     LIQUID
     assigns = { 'foo' => { 'bar' => 'baz' } }
 
-    with_error_modes(:lax, :strict) do
-      assert_template_result("one", template, assigns)
-    end
+    error = assert_raises(Liquid::SyntaxError) { Template.parse(template, assigns) }
 
-    with_error_modes(:rigid) do
-      error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
-
-      assert_match(/Unexpected character =/, error.message)
-    end
+    assert_match(/Unexpected character =/, error.message)
   end
 
   def test_case_when_with_invalid_expression
@@ -115,14 +111,8 @@ class CaseTagUnitTest < Minitest::Test
     LIQUID
     assigns = { 'foo' => { 'bar' => 'baz' } }
 
-    with_error_modes(:lax, :strict) do
-      assert_template_result("one", template, assigns)
-    end
+    error = assert_raises(Liquid::SyntaxError) { Template.parse(template, assigns) }
 
-    with_error_modes(:rigid) do
-      error = assert_raises(Liquid::SyntaxError) { Template.parse(template) }
-
-      assert_match(/Unexpected character =/, error.message)
-    end
+    assert_match(/Unexpected character =/, error.message)
   end
 end

test/unit/variable_unit_test.rb

@@ -72,12 +72,6 @@ class VariableUnitTest < Minitest::Test
     assert_equal([['replace', ['foo', 'bar']], ['textileze', []]], var.filters)
   end
 
-  def test_symbol
-    var = create_variable("http://disney.com/logo.gif | image: 'med' ", error_mode: :lax)
-    assert_equal(VariableLookup.new('http://disney.com/logo.gif'), var.name)
-    assert_equal([['image', ['med']]], var.filters)
-  end
-
   def test_string_to_filter
     var = create_variable("'http://disney.com/logo.gif' | image: 'med' ")
     assert_equal('http://disney.com/logo.gif', var.name)
@@ -108,11 +102,9 @@ class VariableUnitTest < Minitest::Test
     assert_equal(VariableLookup.new('foo-bar'), create_variable('foo-bar').name)
     assert_equal(VariableLookup.new('foo-bar-2'), create_variable('foo-bar-2').name)
 
-    with_error_modes(:strict) do
-      assert_raises(Liquid::SyntaxError) { create_variable('foo - bar') }
-      assert_raises(Liquid::SyntaxError) { create_variable('-foo') }
-      assert_raises(Liquid::SyntaxError) { create_variable('2foo') }
-    end
+    assert_raises(Liquid::SyntaxError) { create_variable('foo - bar') }
+    assert_raises(Liquid::SyntaxError) { create_variable('-foo') }
+    assert_raises(Liquid::SyntaxError) { create_variable('2foo') }
   end
 
   def test_string_with_special_chars
@@ -131,70 +123,38 @@ class VariableUnitTest < Minitest::Test
     assert_equal([['things', [], { 'greeting' => 'world', 'farewell' => 'goodbye' }]], var.filters)
   end
 
-  def test_lax_filter_argument_parsing
-    var = create_variable(%( number_of_comments | pluralize: 'comment': 'comments' ), error_mode: :lax)
-    assert_equal(VariableLookup.new('number_of_comments'), var.name)
-    assert_equal([['pluralize', ['comment', 'comments']]], var.filters)
+  def test_filter_argument_parsing
+    # optional colon
+    var = create_variable(%(n | f1 | f2:))
+    assert_equal([['f1', []], ['f2', []]], var.filters)
 
-    # missing does not throws error
-    create_variable(%(n | f1: ,), error_mode: :lax)
-    create_variable(%(n | f1: ,| f2), error_mode: :lax)
+    # missing argument throws error
+    assert_raises(SyntaxError) { create_variable(%(n | f1: ,)) }
+    assert_raises(SyntaxError) { create_variable(%(n | f1: ,| f2)) }
 
-    # arg does not require colon, but ignores args :O, also ignores first kwarg since it splits on ':'
-    var = create_variable(%(n | f1 1 | f2 k1: v1), error_mode: :lax)
-    assert_equal([['f1', []], ['f2', [VariableLookup.new('v1')]]], var.filters)
+    # arg requires colon
+    assert_raises(SyntaxError) { create_variable(%(n | f1 1)) }
+
+    # trailing comma doesn't throw
+    create_variable(%(n | f1: 1, 2, 3, | f2:))
+
+    # missing comma throws error
+    assert_raises(SyntaxError) { create_variable(%(n | filter: 1 2, 3)) }
 
     # positional and kwargs parsing
-    var = create_variable(%(n | filter: 1, 2, 3 | filter2: k1: 1, k2: 2), error_mode: :lax)
+    var = create_variable(%(n | filter: 1, 2, 3 | filter2: k1: 1, k2: 2))
     assert_equal([['filter', [1, 2, 3]], ['filter2', [], { "k1" => 1, "k2" => 2 }]], var.filters)
 
+    # positional and kwargs mixed
+    var = create_variable(%(n | filter: 'a', 'b', key1: 1, key2: 2, 'c'))
+    assert_equal([["filter", ["a", "b", "c"], { "key1" => 1, "key2" => 2 }]], var.filters)
+
     # positional and kwargs intermixed (pos1, key1: val1, pos2)
-    var = create_variable(%(n | link_to: class: "black", "https://example.com", title: "title"), error_mode: :lax)
+    var = create_variable(%(n | link_to: class: "black", "https://example.com", title: "title"))
     assert_equal([['link_to', ["https://example.com"], { "class" => "black", "title" => "title" }]], var.filters)
-  end
 
-  def test_strict_filter_argument_parsing
-    with_error_modes(:strict) do
-      assert_raises(SyntaxError) do
-        create_variable(%( number_of_comments | pluralize: 'comment': 'comments' ))
-      end
-    end
-  end
-
-  def test_rigid_filter_argument_parsing
-    with_error_modes(:rigid) do
-      # optional colon
-      var = create_variable(%(n | f1 | f2:))
-      assert_equal([['f1', []], ['f2', []]], var.filters)
-
-      # missing argument throws error
-      assert_raises(SyntaxError) { create_variable(%(n | f1: ,)) }
-      assert_raises(SyntaxError) { create_variable(%(n | f1: ,| f2)) }
-
-      # arg requires colon
-      assert_raises(SyntaxError) { create_variable(%(n | f1 1)) }
-
-      # trailing comma doesn't throw
-      create_variable(%(n | f1: 1, 2, 3, | f2:))
-
-      # missing comma throws error
-      assert_raises(SyntaxError) { create_variable(%(n | filter: 1 2, 3)) }
-
-      # positional and kwargs parsing
-      var = create_variable(%(n | filter: 1, 2, 3 | filter2: k1: 1, k2: 2))
-      assert_equal([['filter', [1, 2, 3]], ['filter2', [], { "k1" => 1, "k2" => 2 }]], var.filters)
-
-      # positional and kwargs mixed
-      var = create_variable(%(n | filter: 'a', 'b', key1: 1, key2: 2, 'c'))
-      assert_equal([["filter", ["a", "b", "c"], { "key1" => 1, "key2" => 2 }]], var.filters)
-
-      # positional and kwargs intermixed (pos1, key1: val1, pos2)
-      var = create_variable(%(n | link_to: class: "black", "https://example.com", title: "title"))
-      assert_equal([['link_to', ["https://example.com"], { "class" => "black", "title" => "title" }]], var.filters)
-
-      # string key throws
-      assert_raises(SyntaxError) { create_variable(%(n | pluralize: 'comment': 'comments')) }
-    end
+    # string key throws
+    assert_raises(SyntaxError) { create_variable(%(n | pluralize: 'comment': 'comments')) }
   end
 
   def test_output_raw_source_of_variable