Bump to v5.6.4

remove lru-redux

.github/workflows/liquid.yml

@@ -13,7 +13,8 @@ jobs:
         entry:
           - { ruby: 3.0, allowed-failure: false } # minimum supported
           - { ruby: 3.2, allowed-failure: false }
-          - { ruby: 3.3, allowed-failure: false } # latest
+          - { ruby: 3.3, allowed-failure: false }
+          - { ruby: "3.4.0-rc1", allowed-failure: false } # latest
           - { ruby: ruby-head, allowed-failure: false }
     name: Test Ruby ${{ matrix.entry.ruby }}
     steps:

.ruby-version

@@ -1 +1 @@
-3.3.4
+3.3.6

Gemfile

@@ -13,6 +13,7 @@ group :benchmark, :test do
   gem 'benchmark-ips'
   gem 'memory_profiler'
   gem 'terminal-table'
+  gem "lru_redux"
 
   install_if -> { RUBY_PLATFORM !~ /mingw|mswin|java/ && RUBY_ENGINE != 'truffleruby' } do
     gem 'stackprof'
@@ -23,8 +24,4 @@ group :test do
   gem 'rubocop', '~> 1.61.0'
   gem 'rubocop-shopify', '~> 2.12.0', require: false
   gem 'rubocop-performance', require: false
-
-  platform :mri, :truffleruby do
-    gem 'liquid-c', github: 'Shopify/liquid-c', ref: 'main'
-  end
 end

History.md

@@ -1,5 +1,12 @@
 # Liquid Change Log
 
+## 5.6.0 (unreleased)
+
+### Fixes
+
+* Fix Tokenizer to handle null source value (#1873) [Bahar Pourazar]
+
+
 ## 5.5.0 2024-03-21
 
 Please reference the GitHub release for more information.

README.md

@@ -91,7 +91,7 @@ Liquid::Template.parse(<<~LIQUID, environment: email_environment)
 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.
+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
 

Rakefile

@@ -43,8 +43,6 @@ task :test do
   Rake::Task['base_test'].invoke
 
   if RUBY_ENGINE == 'ruby' || RUBY_ENGINE == 'truffleruby'
-    ENV['LIQUID_C'] = '1'
-
     ENV['LIQUID_PARSER_MODE'] = 'lax'
     Rake::Task['integration_test'].reenable
     Rake::Task['integration_test'].invoke
@@ -73,7 +71,7 @@ end
 
 namespace :benchmark do
   desc "Run the liquid benchmark with lax parsing"
-  task :run do
+  task :lax do
     ruby "./performance/benchmark.rb lax"
   end
 
@@ -82,11 +80,30 @@ namespace :benchmark do
     ruby "./performance/benchmark.rb strict"
   end
 
+  desc "Run the liquid benchmark with both lax and strict parsing"
+  task run: [:lax, :strict]
+
   desc "Run unit benchmarks"
-  task :unit do
-    Dir["./performance/unit/*_benchmark.rb"].each do |file|
-      puts "🧪 Running #{file}"
-      ruby file
+  namespace :unit do
+    task :all do
+      Dir["./performance/unit/*_benchmark.rb"].each do |file|
+        puts "🧪 Running #{file}"
+        ruby file
+      end
+    end
+
+    task :lexer do
+      Dir["./performance/unit/lexer_benchmark.rb"].each do |file|
+        puts "🧪 Running #{file}"
+        ruby file
+      end
+    end
+
+    task :expression do
+      Dir["./performance/unit/expression_benchmark.rb"].each do |file|
+        puts "🧪 Running #{file}"
+        ruby file
+      end
     end
   end
 end

lib/liquid.rb

@@ -21,6 +21,8 @@
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
+require "strscan"
+
 module Liquid
   FilterSeparator             = /\|/
   ArgumentSeparator           = ','
@@ -44,9 +46,7 @@ module Liquid
   VariableParser              = /\[(?>[^\[\]]+|\g<0>)*\]|#{VariableSegment}+\??/o
 
   RAISE_EXCEPTION_LAMBDA = ->(_e) { raise }
-
-  singleton_class.send(:attr_accessor, :cache_classes)
-  self.cache_classes = true
+  HAS_STRING_SCANNER_SCAN_BYTE = StringScanner.instance_methods.include?(:scan_byte)
 end
 
 require "liquid/version"
@@ -71,8 +71,6 @@ require 'liquid/extensions'
 require 'liquid/errors'
 require 'liquid/interrupts'
 require 'liquid/strainer_template'
-require 'liquid/strainer_factory'
-require 'liquid/expression'
 require 'liquid/context'
 require 'liquid/tag'
 require 'liquid/block_body'
@@ -81,6 +79,7 @@ require 'liquid/variable'
 require 'liquid/variable_lookup'
 require 'liquid/range_lookup'
 require 'liquid/resource_limits'
+require 'liquid/expression'
 require 'liquid/template'
 require 'liquid/condition'
 require 'liquid/utils'

lib/liquid/context.rb

@@ -40,6 +40,10 @@ module Liquid
       @global_filter       = nil
       @disabled_tags       = {}
 
+      # Instead of constructing new StringScanner objects for each Expression parse,
+      # we recycle the same one.
+      @string_scanner = StringScanner.new("")
+
       @registers.static[:cached_partials] ||= {}
       @registers.static[:file_system] ||= environment.file_system
       @registers.static[:template_factory] ||= Liquid::TemplateFactory.new
@@ -176,7 +180,7 @@ module Liquid
     # Example:
     #   products == empty #=> products.empty?
     def [](expression)
-      evaluate(Expression.parse(expression))
+      evaluate(Expression.parse(expression, @string_scanner))
     end
 
     def key?(key)

lib/liquid/expression.rb

@@ -10,37 +10,113 @@ module Liquid
       'true' => true,
       'false' => false,
       'blank' => '',
-      'empty' => ''
+      'empty' => '',
+      # in lax mode, minus sign can be a VariableLookup
+      # For simplicity and performace, we treat it like a literal
+      '-' => VariableLookup.parse("-", nil).freeze,
     }.freeze
 
-    INTEGERS_REGEX       = /\A(-?\d+)\z/
-    FLOATS_REGEX         = /\A(-?\d[\d\.]+)\z/
+    DOT = ".".ord
+    ZERO = "0".ord
+    NINE = "9".ord
+    DASH = "-".ord
 
     # Use an atomic group (?>...) to avoid pathological backtracing from
     # malicious input as described in https://github.com/Shopify/liquid/issues/1357
-    RANGES_REGEX         = /\A\(\s*(?>(\S+)\s*\.\.)\s*(\S+)\s*\)\z/
+    RANGES_REGEX = /\A\(\s*(?>(\S+)\s*\.\.)\s*(\S+)\s*\)\z/
+    INTEGER_REGEX = /\A(-?\d+)\z/
+    FLOAT_REGEX = /\A(-?\d+)\.\d+\z/
 
-    def self.parse(markup)
-      return nil unless markup
+    class << self
+      def parse(markup, ss = StringScanner.new(""), cache = nil)
+        return unless markup
 
-      markup = markup.strip
-      if (markup.start_with?('"') && markup.end_with?('"')) ||
-         (markup.start_with?("'") && markup.end_with?("'"))
-        return markup[1..-2]
+        markup = markup.strip # markup can be a frozen string
+
+        if (markup.start_with?('"') && markup.end_with?('"')) ||
+          (markup.start_with?("'") && markup.end_with?("'"))
+          return markup[1..-2]
+        elsif LITERALS.key?(markup)
+          return LITERALS[markup]
+        end
+
+        # Cache only exists during parsing
+        if cache
+          return cache[markup] if cache.key?(markup)
+
+          cache[markup] = inner_parse(markup, ss, cache).freeze
+        else
+          inner_parse(markup, ss, nil).freeze
+        end
       end
 
-      case markup
-      when INTEGERS_REGEX
-        Regexp.last_match(1).to_i
-      when RANGES_REGEX
-        RangeLookup.parse(Regexp.last_match(1), Regexp.last_match(2))
-      when FLOATS_REGEX
-        Regexp.last_match(1).to_f
-      else
-        if LITERALS.key?(markup)
-          LITERALS[markup]
+      def inner_parse(markup, ss, cache)
+        if (markup.start_with?("(") && markup.end_with?(")")) && markup =~ RANGES_REGEX
+          return RangeLookup.parse(
+            Regexp.last_match(1),
+            Regexp.last_match(2),
+            ss,
+            cache,
+          )
+        end
+
+        if (num = parse_number(markup, ss))
+          num
         else
-          VariableLookup.parse(markup)
+          VariableLookup.parse(markup, ss, cache)
+        end
+      end
+
+      def parse_number(markup, ss)
+        # check if the markup is simple integer or float
+        case markup
+        when INTEGER_REGEX
+          return Integer(markup, 10)
+        when FLOAT_REGEX
+          return markup.to_f
+        end
+
+        ss.string = markup
+        # the first byte must be a digit or  a dash
+        byte = ss.scan_byte
+
+        return false if byte != DASH && (byte < ZERO || byte > NINE)
+
+        if byte == DASH
+          peek_byte = ss.peek_byte
+
+          # if it starts with a dash, the next byte must be a digit
+          return false if peek_byte.nil? || !(peek_byte >= ZERO && peek_byte <= NINE)
+        end
+
+        # The markup could be a float with multiple dots
+        first_dot_pos = nil
+        num_end_pos = nil
+
+        while (byte = ss.scan_byte)
+          return false if byte != DOT && (byte < ZERO || byte > NINE)
+
+          # we found our number and now we are just scanning the rest of the string
+          next if num_end_pos
+
+          if byte == DOT
+            if first_dot_pos.nil?
+              first_dot_pos = ss.pos
+            else
+              # we found another dot, so we know that the number ends here
+              num_end_pos = ss.pos - 1
+            end
+          end
+        end
+
+        num_end_pos = markup.length if ss.eos?
+
+        if num_end_pos
+          # number ends with a number "123.123"
+          markup.byteslice(0, num_end_pos).to_f
+        else
+          # number ends with a dot "123."
+          markup.byteslice(0, first_dot_pos).to_f
         end
       end
     end

lib/liquid/lexer.rb

@@ -1,66 +1,7 @@
 # frozen_string_literal: true
 
-require "strscan"
-
 module Liquid
-  class Lexer1
-    SPECIALS = {
-      '|' => :pipe,
-      '.' => :dot,
-      ':' => :colon,
-      ',' => :comma,
-      '[' => :open_square,
-      ']' => :close_square,
-      '(' => :open_round,
-      ')' => :close_round,
-      '?' => :question,
-      '-' => :dash,
-    }.freeze
-    IDENTIFIER            = /[a-zA-Z_][\w-]*\??/
-    SINGLE_STRING_LITERAL = /'[^\']*'/
-    DOUBLE_STRING_LITERAL = /"[^\"]*"/
-    STRING_LITERAL        = Regexp.union(SINGLE_STRING_LITERAL, DOUBLE_STRING_LITERAL)
-    NUMBER_LITERAL        = /-?\d+(\.\d+)?/
-    DOTDOT                = /\.\./
-    COMPARISON_OPERATOR   = /==|!=|<>|<=?|>=?|contains(?=\s)/
-    WHITESPACE_OR_NOTHING = /\s*/
-
-    def initialize(input)
-      @ss = StringScanner.new(input)
-    end
-
-    def tokenize
-      @output = []
-
-      until @ss.eos?
-        @ss.skip(WHITESPACE_OR_NOTHING)
-        break if @ss.eos?
-        tok      = if (t = @ss.scan(COMPARISON_OPERATOR))
-          [:comparison, t]
-        elsif (t = @ss.scan(STRING_LITERAL))
-          [:string, t]
-        elsif (t = @ss.scan(NUMBER_LITERAL))
-          [:number, t]
-        elsif (t = @ss.scan(IDENTIFIER))
-          [:id, t]
-        elsif (t = @ss.scan(DOTDOT))
-          [:dotdot, t]
-        else
-          c     = @ss.getch
-          if (s = SPECIALS[c])
-            [s, c]
-          else
-            raise SyntaxError, "Unexpected character #{c}"
-          end
-        end
-        @output << tok
-      end
-
-      @output << [:end_of_string]
-    end
-  end
-
-  class Lexer2
+  class Lexer
     CLOSE_ROUND = [:close_round, ")"].freeze
     CLOSE_SQUARE = [:close_square, "]"].freeze
     COLON = [:colon, ":"].freeze
@@ -92,6 +33,7 @@ module Liquid
     SINGLE_COMPARISON_TOKENS = [].tap do |table|
       table["<".ord] = COMPARISON_LESS_THAN
       table[">".ord] = COMPARISON_GREATER_THAN
+      table.freeze
     end
 
     TWO_CHARS_COMPARISON_JUMP_TABLE = [].tap do |table|
@@ -103,18 +45,17 @@ module Liquid
         sub_table["=".ord] = COMPARISION_NOT_EQUAL
         sub_table.freeze
       end
+      table.freeze
     end
 
     COMPARISON_JUMP_TABLE = [].tap do |table|
       table["<".ord] = [].tap do |sub_table|
         sub_table["=".ord] = COMPARISON_LESS_THAN_OR_EQUAL
         sub_table[">".ord] = COMPARISON_NOT_EQUAL_ALT
-        RUBY_WHITESPACE.each { |c| sub_table[c.ord] = COMPARISON_LESS_THAN }
         sub_table.freeze
       end
       table[">".ord] = [].tap do |sub_table|
         sub_table["=".ord] = COMPARISON_GREATER_THAN_OR_EQUAL
-        RUBY_WHITESPACE.each { |c| sub_table[c.ord] = COMPARISON_GREATER_THAN }
         sub_table.freeze
       end
       table.freeze
@@ -157,81 +98,76 @@ module Liquid
       table.freeze
     end
 
-    def initialize(input)
-      @ss = StringScanner.new(input)
-    end
-
     # rubocop:disable Metrics/BlockNesting
-    def tokenize
-      @output = []
+    class << self
+      def tokenize(ss)
+        output = []
 
-      until @ss.eos?
-        @ss.skip(WHITESPACE_OR_NOTHING)
+        until ss.eos?
+          ss.skip(WHITESPACE_OR_NOTHING)
 
-        break if @ss.eos?
+          break if ss.eos?
 
-        start_pos = @ss.pos
-        peeked = @ss.peek_byte
+          start_pos = ss.pos
+          peeked = ss.peek_byte
 
-        if (special = SPECIAL_TABLE[peeked])
-          @ss.scan_byte
-          # Special case for ".."
-          if special == DOT && @ss.peek_byte == DOT_ORD
-            @ss.scan_byte
-            @output << DOTDOT
-          elsif special == DASH
-            # Special case for negative numbers
-            if (peeked_byte = @ss.peek_byte) && NUMBER_TABLE[peeked_byte]
-              @ss.pos -= 1
-              @output << [:number, @ss.scan(NUMBER_LITERAL)]
+          if (special = SPECIAL_TABLE[peeked])
+            ss.scan_byte
+            # Special case for ".."
+            if special == DOT && ss.peek_byte == DOT_ORD
+              ss.scan_byte
+              output << DOTDOT
+            elsif special == DASH
+              # Special case for negative numbers
+              if (peeked_byte = ss.peek_byte) && NUMBER_TABLE[peeked_byte]
+                ss.pos -= 1
+                output << [:number, ss.scan(NUMBER_LITERAL)]
+              else
+                output << special
+              end
             else
-              @output << special
+              output << special
+            end
+          elsif (sub_table = TWO_CHARS_COMPARISON_JUMP_TABLE[peeked])
+            ss.scan_byte
+            if (peeked_byte = ss.peek_byte) && (found = sub_table[peeked_byte])
+              output << found
+              ss.scan_byte
+            else
+              raise_syntax_error(start_pos, ss)
+            end
+          elsif (sub_table = COMPARISON_JUMP_TABLE[peeked])
+            ss.scan_byte
+            if (peeked_byte = ss.peek_byte) && (found = sub_table[peeked_byte])
+              output << found
+              ss.scan_byte
+            else
+              output << SINGLE_COMPARISON_TOKENS[peeked]
             end
           else
-            @output << special
-          end
-        elsif (sub_table = TWO_CHARS_COMPARISON_JUMP_TABLE[peeked])
-          @ss.scan_byte
-          if (peeked_byte = @ss.peek_byte) && (found = sub_table[peeked_byte])
-            @output << found
-            @ss.scan_byte
-          else
-            raise_syntax_error(start_pos)
-          end
-        elsif (sub_table = COMPARISON_JUMP_TABLE[peeked])
-          @ss.scan_byte
-          if (peeked_byte = @ss.peek_byte) && (found = sub_table[peeked_byte])
-            @output << found
-            @ss.scan_byte
-          else
-            @output << SINGLE_COMPARISON_TOKENS[peeked]
-          end
-        else
-          type, pattern = NEXT_MATCHER_JUMP_TABLE[peeked]
+            type, pattern = NEXT_MATCHER_JUMP_TABLE[peeked]
 
-          if type && (t = @ss.scan(pattern))
-            # Special case for "contains"
-            @output << if type == :id && t == "contains" && @output.last&.first != :dot
-              COMPARISON_CONTAINS
+            if type && (t = ss.scan(pattern))
+              # Special case for "contains"
+              output << if type == :id && t == "contains" && output.last&.first != :dot
+                COMPARISON_CONTAINS
+              else
+                [type, t]
+              end
             else
-              [type, t]
+              raise_syntax_error(start_pos, ss)
             end
-          else
-            raise_syntax_error(start_pos)
           end
         end
+        # rubocop:enable Metrics/BlockNesting
+        output << EOS
       end
-      # rubocop:enable Metrics/BlockNesting
 
-      @output << EOS
-    end
-
-    def raise_syntax_error(start_pos)
-      @ss.pos = start_pos
-      # the character could be a UTF-8 character, use getch to get all the bytes
-      raise SyntaxError, "Unexpected character #{@ss.getch}"
+      def raise_syntax_error(start_pos, ss)
+        ss.pos = start_pos
+        # the character could be a UTF-8 character, use getch to get all the bytes
+        raise SyntaxError, "Unexpected character #{ss.getch}"
+      end
     end
   end
-
-  Lexer = StringScanner.instance_methods.include?(:scan_byte) ? Lexer2 : Lexer1
 end

lib/liquid/parse_context.rb

@@ -12,6 +12,18 @@ module Liquid
       @locale   = @template_options[:locale] ||= I18n.new
       @warnings = []
 
+      # constructing new StringScanner in Lexer, Tokenizer, etc is expensive
+      # This StringScanner will be shared by all of them
+      @string_scanner = StringScanner.new("")
+
+      @expression_cache = if options[:expression_cache].nil?
+        {}
+      elsif options[:expression_cache].respond_to?(:[]) && options[:expression_cache].respond_to?(:[]=)
+        options[:expression_cache]
+      elsif options[:expression_cache]
+        {}
+      end
+
       self.depth   = 0
       self.partial = false
     end
@@ -24,12 +36,22 @@ module Liquid
       Liquid::BlockBody.new
     end
 
-    def new_tokenizer(markup, start_line_number: nil, for_liquid_tag: false)
-      Tokenizer.new(markup, line_number: start_line_number, for_liquid_tag: for_liquid_tag)
+    def new_parser(input)
+      @string_scanner.string = input
+      Parser.new(@string_scanner)
+    end
+
+    def new_tokenizer(source, start_line_number: nil, for_liquid_tag: false)
+      Tokenizer.new(
+        source: source,
+        string_scanner: @string_scanner,
+        line_number: start_line_number,
+        for_liquid_tag: for_liquid_tag,
+      )
     end
 
     def parse_expression(markup)
-      Expression.parse(markup)
+      Expression.parse(markup, @string_scanner, @expression_cache)
     end
 
     def partial=(value)

lib/liquid/parser.rb

@@ -3,8 +3,8 @@
 module Liquid
   class Parser
     def initialize(input)
-      l       = Lexer.new(input)
-      @tokens = l.tokenize
+      ss = input.is_a?(StringScanner) ? input : StringScanner.new(input)
+      @tokens = Lexer.tokenize(ss)
       @p      = 0 # pointer to current location
     end
 

lib/liquid/range_lookup.rb

@@ -2,9 +2,9 @@
 
 module Liquid
   class RangeLookup
-    def self.parse(start_markup, end_markup)
-      start_obj = Expression.parse(start_markup)
-      end_obj   = Expression.parse(end_markup)
+    def self.parse(start_markup, end_markup, string_scanner, cache = nil)
+      start_obj = Expression.parse(start_markup, string_scanner, cache)
+      end_obj   = Expression.parse(end_markup, string_scanner, cache)
       if start_obj.respond_to?(:evaluate) || end_obj.respond_to?(:evaluate)
         new(start_obj, end_obj)
       else

lib/liquid/strainer_factory.rb

@@ -1,23 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  # StrainerFactory is the factory for the filters system.
-  module StrainerFactory
-    extend self
-
-    def add_global_filter(filter, environment = Environment.default)
-      Deprecations.warn("StrainerFactory.add_global_filter", "Environment#register_filter")
-      environment.register_filter(filter)
-    end
-
-    def create(context, filters = Const::EMPTY_ARRAY, environment = Environment.default)
-      Deprecations.warn("StrainerFactory.create", "StrainerFactory.create_strainer")
-      environment.create_strainer(context, filters)
-    end
-
-    def global_filter_names(environment = Environment.default)
-      Deprecations.warn("StrainerFactory.global_filter_names", "Environment#filter_method_names")
-      Environment.strainer_template.filter_method_names
-    end
-  end
-end

lib/liquid/tags/cycle.rb

@@ -68,7 +68,13 @@ module Liquid
     def variables_from_string(markup)
       markup.split(',').collect do |var|
         var =~ /\s*(#{QuotedFragment})\s*/o
-        Regexp.last_match(1) ? parse_expression(Regexp.last_match(1)) : nil
+        next unless Regexp.last_match(1)
+
+        # Expression Parser returns cached objects, and we need to dup them to
+        # start the cycle over for each new cycle call.
+        # Liquid-C does not have a cache, so we don't need to dup the object.
+        var = parse_expression(Regexp.last_match(1))
+        var.is_a?(VariableLookup) ? var.dup : var
       end.compact
     end
 

lib/liquid/tags/for.rb

@@ -88,7 +88,7 @@ module Liquid
     end
 
     def strict_parse(markup)
-      p = Parser.new(markup)
+      p = @parse_context.new_parser(markup)
       @variable_name = p.consume(:id)
       raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_in") unless p.id?('in')
 

lib/liquid/tags/if.rb

@@ -102,7 +102,7 @@ module Liquid
     end
 
     def strict_parse(markup)
-      p = Parser.new(markup)
+      p = @parse_context.new_parser(markup)
       condition = parse_binary_comparisons(p)
       p.consume(:end_of_string)
       condition

lib/liquid/tokenizer.rb

@@ -1,20 +1,43 @@
 # frozen_string_literal: true
 
+require "strscan"
+
 module Liquid
   class Tokenizer
     attr_reader :line_number, :for_liquid_tag
 
-    def initialize(source, line_numbers = false, line_number: nil, for_liquid_tag: false)
-      @source         = source
-      @line_number    = line_number || (line_numbers ? 1 : nil)
+    TAG_END = /%\}/
+    TAG_OR_VARIABLE_START = /\{[\{\%]/
+    NEWLINE = /\n/
+
+    OPEN_CURLEY = "{".ord
+    CLOSE_CURLEY = "}".ord
+    PERCENTAGE = "%".ord
+
+    def initialize(
+      source:,
+      string_scanner:,
+      line_numbers: false,
+      line_number: nil,
+      for_liquid_tag: false
+    )
+      @line_number = line_number || (line_numbers ? 1 : nil)
       @for_liquid_tag = for_liquid_tag
-      @offset         = 0
-      @tokens         = tokenize
+      @source = source.to_s.to_str
+      @offset = 0
+      @tokens = []
+
+      if @source
+        @ss = string_scanner
+        @ss.string = @source
+        tokenize
+      end
     end
 
     def shift
       token = @tokens[@offset]
-      return nil unless token
+
+      return unless token
 
       @offset += 1
 
@@ -28,18 +51,105 @@ module Liquid
     private
 
     def tokenize
-      return [] if @source.empty?
-
-      return @source.split("\n") if @for_liquid_tag
-
-      tokens = @source.split(TemplateParser)
-
-      # removes the rogue empty element at the beginning of the array
-      if tokens[0]&.empty?
-        @offset += 1
+      if @for_liquid_tag
+        @tokens = @source.split("\n")
+      else
+        @tokens << shift_normal until @ss.eos?
       end
 
-      tokens
+      @source = nil
+      @ss = nil
+    end
+
+    def shift_normal
+      token = next_token
+
+      return unless token
+
+      token
+    end
+
+    def next_token
+      # possible states: :text, :tag, :variable
+      byte_a = @ss.peek_byte
+
+      if byte_a == OPEN_CURLEY
+        @ss.scan_byte
+
+        byte_b = @ss.peek_byte
+
+        if byte_b == PERCENTAGE
+          @ss.scan_byte
+          return next_tag_token
+        elsif byte_b == OPEN_CURLEY
+          @ss.scan_byte
+          return next_variable_token
+        end
+
+        @ss.pos -= 1
+      end
+
+      next_text_token
+    end
+
+    def next_text_token
+      start = @ss.pos
+
+      unless @ss.skip_until(TAG_OR_VARIABLE_START)
+        token = @ss.rest
+        @ss.terminate
+        return token
+      end
+
+      pos = @ss.pos -= 2
+      @source.byteslice(start, pos - start)
+    end
+
+    def next_variable_token
+      start = @ss.pos - 2
+
+      byte_a = byte_b = @ss.scan_byte
+
+      while byte_b
+        byte_a = @ss.scan_byte while byte_a && (byte_a != CLOSE_CURLEY && byte_a != OPEN_CURLEY)
+
+        break unless byte_a
+
+        if @ss.eos?
+          return byte_a == CLOSE_CURLEY ? @source.byteslice(start, @ss.pos - start) : "{{"
+        end
+
+        byte_b = @ss.scan_byte
+
+        if byte_a == CLOSE_CURLEY
+          if byte_b == CLOSE_CURLEY
+            return @source.byteslice(start, @ss.pos - start)
+          elsif byte_b != CLOSE_CURLEY
+            @ss.pos -= 1
+            return @source.byteslice(start, @ss.pos - start)
+          end
+        elsif byte_a == OPEN_CURLEY && byte_b == PERCENTAGE
+          return next_tag_token_with_start(start)
+        end
+
+        byte_a = byte_b
+      end
+
+      "{{"
+    end
+
+    def next_tag_token
+      start = @ss.pos - 2
+      if (len = @ss.skip_until(TAG_END))
+        @source.byteslice(start, len + 2)
+      else
+        "{%"
+      end
+    end
+
+    def next_tag_token_with_start(start)
+      @ss.skip_until(TAG_END)
+      @source.byteslice(start, @ss.pos - start)
     end
   end
 end

lib/liquid/variable.rb

@@ -61,7 +61,7 @@ module Liquid
 
     def strict_parse(markup)
       @filters = []
-      p = Parser.new(markup)
+      p = @parse_context.new_parser(markup)
 
       return if p.look(:end_of_string)
 
@@ -95,15 +95,21 @@ module Liquid
 
     def render_to_output_buffer(context, output)
       obj = render(context)
+      render_obj_to_output(obj, output)
+      output
+    end
 
-      if obj.is_a?(Array)
-        output << obj.join
-      elsif obj.nil?
-      else
+    def render_obj_to_output(obj, output)
+      case obj
+      when NilClass
+        # Do nothing
+      when Array
+        obj.each do |o|
+          render_obj_to_output(o, output)
+        end
+      when
         output << obj.to_s
       end
-
-      output
     end
 
     def disabled?(_context)

lib/liquid/variable_lookup.rb

@@ -6,16 +6,20 @@ module Liquid
 
     attr_reader :name, :lookups
 
-    def self.parse(markup)
-      new(markup)
+    def self.parse(markup, string_scanner = StringScanner.new(""), cache = nil)
+      new(markup, string_scanner, cache)
     end
 
-    def initialize(markup)
+    def initialize(markup, string_scanner = StringScanner.new(""), cache = nil)
       lookups = markup.scan(VariableParser)
 
       name = lookups.shift
       if name&.start_with?('[') && name&.end_with?(']')
-        name = Expression.parse(name[1..-2])
+        name = Expression.parse(
+          name[1..-2],
+          string_scanner,
+          cache,
+        )
       end
       @name = name
 
@@ -25,7 +29,11 @@ module Liquid
       @lookups.each_index do |i|
         lookup = lookups[i]
         if lookup&.start_with?('[') && lookup&.end_with?(']')
-          lookups[i] = Expression.parse(lookup[1..-2])
+          lookups[i] = Expression.parse(
+            lookup[1..-2],
+            string_scanner,
+            cache,
+          )
         elsif COMMAND_METHODS.include?(lookup)
           @command_flags |= 1 << i
         end

lib/liquid/version.rb

@@ -2,5 +2,5 @@
 # frozen_string_literal: true
 
 module Liquid
-  VERSION = "5.6.0.alpha"
+  VERSION = "5.6.4"
 end

liquid.gemspec

@@ -13,7 +13,7 @@ Gem::Specification.new do |s|
   s.summary     = "A secure, non-evaling end user template engine with aesthetic markup."
   s.authors     = ["Tobias Lütke"]
   s.email       = ["[email protected]"]
-  s.homepage    = "http://www.liquidmarkup.org"
+  s.homepage    = "https://shopify.github.io/liquid/"
   s.license     = "MIT"
   # s.description = "A secure, non-evaling end user template engine with aesthetic markup."
 
@@ -28,7 +28,7 @@ Gem::Specification.new do |s|
 
   s.require_path = "lib"
 
-  s.add_dependency("strscan")
+  s.add_dependency("strscan", ">= 3.1.1")
   s.add_dependency("bigdecimal")
 
   s.add_development_dependency('rake', '~> 13.0')

performance/benchmark.rb

@@ -4,18 +4,22 @@ require 'benchmark/ips'
 require_relative 'theme_runner'
 
 RubyVM::YJIT.enable if defined?(RubyVM::YJIT)
-Liquid::Template.error_mode = ARGV.first.to_sym if ARGV.first
+Liquid::Environment.default.error_mode = ARGV.first.to_sym if ARGV.first
+
 profiler = ThemeRunner.new
 
 Benchmark.ips do |x|
-  x.time   = 10
-  x.warmup = 5
+  x.time   = 20
+  x.warmup = 10
 
   puts
   puts "Running benchmark for #{x.time} seconds (with #{x.warmup} seconds warmup)."
   puts
 
-  x.report("parse:") { profiler.compile }
-  x.report("render:") { profiler.render }
-  x.report("parse & render:") { profiler.run }
+  phase = ENV["PHASE"] || "all"
+
+  x.report("tokenize:") { profiler.tokenize } if phase == "all" || phase == "tokenize"
+  x.report("parse:") { profiler.compile } if phase == "all" || phase == "parse"
+  x.report("render:") { profiler.render } if phase == "all" || phase == "render"
+  x.report("parse & render:") { profiler.run } if phase == "all" || phase == "run"
 end

performance/shopify/liquid.rb

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

performance/theme_runner.rb

@@ -48,6 +48,19 @@ class ThemeRunner
     end
   end
 
+  # `tokenize` will just test the tokenizen portion of liquid without any templates
+  def tokenize
+    ss = StringScanner.new("")
+    @tests.each do |test_hash|
+      tokenizer = Liquid::Tokenizer.new(
+        source: test_hash[:liquid],
+        string_scanner: ss,
+        line_numbers: true,
+      )
+      while tokenizer.shift; end
+    end
+  end
+
   # `run` is called to benchmark rendering and compiling at the same time
   def run
     each_test do |liquid, layout, assigns, page_template, template_name|

performance/unit/expression_benchmark.rb

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

performance/unit/lexer_benchmark.rb

@@ -29,31 +29,12 @@ EXPRESSIONS = [
   "foo | default: -1",
 ]
 
-EXPRESSIONS.each do |expr|
-  lexer_1_result = Liquid::Lexer1.new(expr).tokenize
-  lexer_2_result = Liquid::Lexer2.new(expr).tokenize
-
-  next if lexer_1_result == lexer_2_result
-
-  warn "Lexer1 and Lexer2 results are different for expression: #{expr}"
-  warn "expected: #{lexer_1_result}"
-  warn "got: #{lexer_2_result}"
-  abort
-end
-
 Benchmark.ips do |x|
   x.config(time: 10, warmup: 5)
 
-  x.report("Liquid::Lexer1#tokenize") do
+  x.report("Liquid::Lexer#tokenize") do
     EXPRESSIONS.each do |expr|
-      l = Liquid::Lexer1.new(expr)
-      l.tokenize
-    end
-  end
-
-  x.report("Liquid::Lexer2#tokenize") do
-    EXPRESSIONS.each do |expr|
-      l = Liquid::Lexer2.new(expr)
+      l = Liquid::Lexer.new(expr)
       l.tokenize
     end
   end

test/integration/error_handling_test.rb

@@ -203,20 +203,19 @@ class ErrorHandlingTest < Minitest::Test
   end
 
   def test_setting_default_exception_renderer
-    old_exception_renderer = Liquid::Template.default_exception_renderer
     exceptions = []
-    Liquid::Template.default_exception_renderer = ->(e) {
+    default_exception_renderer = ->(e) {
       exceptions << e
       ''
     }
-    template = Liquid::Template.parse('This is a runtime error: {{ errors.argument_error }}')
+
+    env = Liquid::Environment.build(exception_renderer: default_exception_renderer)
+    template = Liquid::Template.parse('This is a runtime error: {{ errors.argument_error }}', environment: env)
 
     output = template.render('errors' => ErrorDrop.new)
 
     assert_equal('This is a runtime error: ', output)
     assert_equal([Liquid::ArgumentError], template.errors.map(&:class))
-  ensure
-    Liquid::Template.default_exception_renderer = old_exception_renderer if old_exception_renderer
   end
 
   def test_setting_exception_renderer_on_environment

test/integration/expression_test.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require 'test_helper'
+require 'lru_redux'
 
 class ExpressionTest < Minitest::Test
   def test_keyword_literals
@@ -13,6 +14,7 @@ class ExpressionTest < Minitest::Test
     assert_template_result("double quoted", '{{"double quoted"}}')
     assert_template_result("spaced", "{{ 'spaced' }}")
     assert_template_result("spaced2", "{{ 'spaced2' }}")
+    assert_template_result("emoji🔥", "{{ 'emoji🔥' }}")
   end
 
   def test_int
@@ -22,8 +24,18 @@ class ExpressionTest < Minitest::Test
   end
 
   def test_float
+    assert_template_result("-17.42", "{{ -17.42 }}")
     assert_template_result("2.5", "{{ 2.5 }}")
+    assert_expression_result(0.0, "0.....5")
+    assert_expression_result(0.0, "-0..1")
     assert_expression_result(1.5, "1.5")
+
+    # this is a unfortunate quirky behavior of Liquid
+    result = Expression.parse(".5")
+    assert_kind_of(Liquid::VariableLookup, result)
+
+    result = Expression.parse("-.5")
+    assert_kind_of(Liquid::VariableLookup, result)
   end
 
   def test_range
@@ -40,6 +52,101 @@ 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' - }}",
+    )
+  end
+
+  def test_expression_cache
+    skip("Liquid-C does not support Expression caching") if defined?(Liquid::C) && Liquid::C.enabled
+
+    cache = {}
+    template = <<~LIQUID
+      {% assign x = 1 %}
+      {{ x }}
+      {% assign x = 2 %}
+      {{ x }}
+      {% assign y = 1 %}
+      {{ y }}
+    LIQUID
+
+    Liquid::Template.parse(template, expression_cache: cache).render
+
+    assert_equal(
+      ["1", "2", "x", "y"],
+      cache.to_a.map { _1[0] }.sort,
+    )
+  end
+
+  def test_expression_cache_with_true_boolean
+    skip("Liquid-C does not support Expression caching") if defined?(Liquid::C) && Liquid::C.enabled
+
+    template = <<~LIQUID
+      {% assign x = 1 %}
+      {{ x }}
+      {% assign x = 2 %}
+      {{ x }}
+      {% assign y = 1 %}
+      {{ y }}
+    LIQUID
+
+    parse_context = ParseContext.new(expression_cache: true)
+
+    Liquid::Template.parse(template, parse_context).render
+
+    cache = parse_context.instance_variable_get(:@expression_cache)
+
+    assert_equal(
+      ["1", "2", "x", "y"],
+      cache.to_a.map { _1[0] }.sort,
+    )
+  end
+
+  def test_expression_cache_with_lru_redux
+    skip("Liquid-C does not support Expression caching") if defined?(Liquid::C) && Liquid::C.enabled
+
+    cache = LruRedux::Cache.new(10)
+    template = <<~LIQUID
+      {% assign x = 1 %}
+      {{ x }}
+      {% assign x = 2 %}
+      {{ x }}
+      {% assign y = 1 %}
+      {{ y }}
+    LIQUID
+
+    Liquid::Template.parse(template, expression_cache: cache).render
+
+    assert_equal(
+      ["1", "2", "x", "y"],
+      cache.to_a.map { _1[0] }.sort,
+    )
+  end
+
+  def test_disable_expression_cache
+    skip("Liquid-C does not support Expression caching") if defined?(Liquid::C) && Liquid::C.enabled
+
+    template = <<~LIQUID
+      {% assign x = 1 %}
+      {{ x }}
+      {% assign x = 2 %}
+      {{ x }}
+      {% assign y = 1 %}
+      {{ y }}
+    LIQUID
+
+    parse_context = Liquid::ParseContext.new(expression_cache: false)
+    Liquid::Template.parse(template, parse_context).render
+    assert(parse_context.instance_variable_get(:@expression_cache).nil?)
+  end
+
   private
 
   def assert_expression_result(expect, markup, **assigns)

test/integration/parsing_quirks_test.rb

@@ -134,6 +134,14 @@ class ParsingQuirksTest < Minitest::Test
 
   def test_incomplete_expression
     with_error_mode(:lax) do
+      assert_template_result("false", "{{ false - }}")
+      assert_template_result("false", "{{ false > }}")
+      assert_template_result("false", "{{ false < }}")
+      assert_template_result("false", "{{ false = }}")
+      assert_template_result("false", "{{ false ! }}")
+      assert_template_result("false", "{{ false 1 }}")
+      assert_template_result("false", "{{ false a }}")
+
       assert_template_result("false", "{% liquid assign foo = false -\n%}{{ foo }}")
       assert_template_result("false", "{% liquid assign foo = false >\n%}{{ foo }}")
       assert_template_result("false", "{% liquid assign foo = false <\n%}{{ foo }}")

test/integration/profiler_test.rb

@@ -33,7 +33,7 @@ class ProfilerTest < Minitest::Test
   end
 
   def setup
-    Liquid::Template.file_system = ProfilingFileSystem.new
+    Liquid::Environment.default.file_system = ProfilingFileSystem.new
   end
 
   def test_template_allows_flagging_profiling

test/integration/tags/cycle_tag_test.rb

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

test/integration/tags/include_tag_test.rb

@@ -174,10 +174,10 @@ class IncludeTagTest < Minitest::Test
       end
     end
 
-    Liquid::Template.file_system = infinite_file_system.new
+    env = Liquid::Environment.build(file_system: infinite_file_system.new)
 
     assert_raises(Liquid::StackLevelError) do
-      Template.parse("{% include 'loop' %}").render!
+      Template.parse("{% include 'loop' %}", environment: env).render!
     end
   end
 
@@ -264,26 +264,27 @@ class IncludeTagTest < Minitest::Test
   end
 
   def test_does_not_add_error_in_strict_mode_for_missing_variable
-    Liquid::Template.file_system = TestFileSystem.new
+    env = Liquid::Environment.build(file_system: TestFileSystem.new)
 
-    a = Liquid::Template.parse(' {% include "nested_template" %}')
+    a = Liquid::Template.parse(' {% include "nested_template" %}', environment: env)
     a.render!
     assert_empty(a.errors)
   end
 
   def test_passing_options_to_included_templates
-    Liquid::Template.file_system = TestFileSystem.new
+    env = Liquid::Environment.build(file_system: TestFileSystem.new)
+
     assert_raises(Liquid::SyntaxError) do
-      Template.parse("{% include template %}", error_mode: :strict).render!("template" => '{{ "X" || downcase }}')
+      Template.parse("{% include template %}", error_mode: :strict, environment: env).render!("template" => '{{ "X" || downcase }}')
     end
     with_error_mode(:lax) do
-      assert_equal('x', Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: true).render!("template" => '{{ "X" || downcase }}'))
+      assert_equal('x', Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: true, environment: env).render!("template" => '{{ "X" || downcase }}'))
     end
     assert_raises(Liquid::SyntaxError) do
-      Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: [:locale]).render!("template" => '{{ "X" || downcase }}')
+      Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: [:locale], environment: env).render!("template" => '{{ "X" || downcase }}')
     end
     with_error_mode(:lax) do
-      assert_equal('x', Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: [:error_mode]).render!("template" => '{{ "X" || downcase }}'))
+      assert_equal('x', Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: [:error_mode], environment: env).render!("template" => '{{ "X" || downcase }}'))
     end
   end
 
@@ -334,8 +335,11 @@ class IncludeTagTest < Minitest::Test
   end
 
   def test_including_with_strict_variables
-    Liquid::Template.file_system = StubFileSystem.new({ "simple" => "simple" })
-    template = Liquid::Template.parse("{% include 'simple' %}", error_mode: :warn)
+    env = Liquid::Environment.build(
+      file_system: StubFileSystem.new('simple' => 'simple'),
+    )
+
+    template = Liquid::Template.parse("{% include 'simple' %}", error_mode: :warn, environment: env)
     template.render(nil, strict_variables: true)
 
     assert_equal([], template.errors)

test/integration/tags/raw_tag_test.rb

@@ -16,6 +16,7 @@ class RawTagTest < Minitest::Test
     assert_template_result('>{{ test }}<', '> {%- raw -%}{{ test }}{%- endraw -%} <')
     assert_template_result("> inner  <", "> {%- raw -%} inner {%- endraw %} <")
     assert_template_result("> inner <", "> {%- raw -%} inner {%- endraw -%} <")
+    assert_template_result("{Hello}", "{% raw %}{{% endraw %}Hello{% raw %}}{% endraw %}")
   end
 
   def test_open_tag_in_raw

test/integration/tags/render_tag_test.rb

@@ -82,19 +82,22 @@ class RenderTagTest < Minitest::Test
   end
 
   def test_recursively_rendered_template_does_not_produce_endless_loop
-    Liquid::Template.file_system = StubFileSystem.new('loop' => '{% render "loop" %}')
+    env = Liquid::Environment.build(
+      file_system: StubFileSystem.new('loop' => '{% render "loop" %}'),
+    )
 
     assert_raises(Liquid::StackLevelError) do
-      Template.parse('{% render "loop" %}').render!
+      Template.parse('{% render "loop" %}', environment: env).render!
     end
   end
 
   def test_sub_contexts_count_towards_the_same_recursion_limit
-    Liquid::Template.file_system = StubFileSystem.new(
-      'loop_render' => '{% render "loop_render" %}',
+    env = Liquid::Environment.build(
+      file_system: StubFileSystem.new('loop_render' => '{% render "loop_render" %}'),
     )
+
     assert_raises(Liquid::StackLevelError) do
-      Template.parse('{% render "loop_render" %}').render!
+      Template.parse('{% render "loop_render" %}', environment: env).render!
     end
   end
 

test/integration/variable_test.rb

@@ -130,6 +130,10 @@ class VariableTest < Minitest::Test
     assert_template_result('bar', '{{ foo }}', { 'foo' => :bar })
   end
 
+  def test_nested_array
+    assert_template_result('', '{{ foo }}', { 'foo' => [[nil]] })
+  end
+
   def test_dynamic_find_var
     assert_template_result('bar', '{{ [key] }}', { 'key' => 'foo', 'foo' => 'bar' })
   end

test/test_helper.rb

@@ -13,12 +13,7 @@ if (env_mode = ENV['LIQUID_PARSER_MODE'])
   puts "-- #{env_mode.upcase} ERROR MODE"
   mode = env_mode.to_sym
 end
-Liquid::Template.error_mode = mode
-
-if ENV['LIQUID_C'] == '1'
-  puts "-- LIQUID C"
-  require 'liquid/c'
-end
+Liquid::Environment.default.error_mode = mode
 
 if Minitest.const_defined?('Test')
   # We're on Minitest 5+. Nothing to do here.
@@ -88,11 +83,11 @@ module Minitest
     end
 
     def with_error_mode(mode)
-      old_mode = Liquid::Template.error_mode
-      Liquid::Template.error_mode = mode
+      old_mode = Liquid::Environment.default.error_mode
+      Liquid::Environment.default.error_mode = mode
       yield
     ensure
-      Liquid::Template.error_mode = old_mode
+      Liquid::Environment.default.error_mode = old_mode
     end
 
     def with_custom_tag(tag_name, tag_class, &block)

test/unit/environment_filter_test.rb

@@ -2,7 +2,7 @@
 
 require 'test_helper'
 
-class StrainerFactoryUnitTest < Minitest::Test
+class EnvironmentFilterTest < Minitest::Test
   include Liquid
 
   module AccessScopeFilters
@@ -16,8 +16,6 @@ class StrainerFactoryUnitTest < Minitest::Test
     private :private_filter
   end
 
-  StrainerFactory.add_global_filter(AccessScopeFilters)
-
   module LateAddedFilter
     def late_added_filter(_input)
       "filtered"
@@ -25,24 +23,28 @@ class StrainerFactoryUnitTest < Minitest::Test
   end
 
   def setup
-    @context = Context.build
+    @environment = Liquid::Environment.build do |env|
+      env.register_filter(AccessScopeFilters)
+    end
+
+    @context = Context.build(environment: @environment)
   end
 
   def test_strainer
-    strainer = StrainerFactory.create(@context)
+    strainer = @environment.create_strainer(@context)
     assert_equal(5, strainer.invoke('size', 'input'))
     assert_equal("public", strainer.invoke("public_filter"))
   end
 
-  def test_stainer_raises_argument_error
-    strainer = StrainerFactory.create(@context)
+  def test_strainer_raises_argument_error
+    strainer = @environment.create_strainer(@context)
     assert_raises(Liquid::ArgumentError) do
       strainer.invoke("public_filter", 1)
     end
   end
 
-  def test_stainer_argument_error_contains_backtrace
-    strainer = StrainerFactory.create(@context)
+  def test_strainer_argument_error_contains_backtrace
+    strainer = @environment.create_strainer(@context)
 
     exception = assert_raises(Liquid::ArgumentError) do
       strainer.invoke("public_filter", 1)
@@ -52,12 +54,13 @@ class StrainerFactoryUnitTest < Minitest::Test
       /\ALiquid error: wrong number of arguments \((1 for 0|given 1, expected 0)\)\z/,
       exception.message,
     )
+
     source = AccessScopeFilters.instance_method(:public_filter).source_location
-    assert_equal(source.map(&:to_s), exception.backtrace[0].split(':')[0..1])
+    assert_equal(source[0..1].map(&:to_s), exception.backtrace[0].split(':')[0..1])
   end
 
   def test_strainer_only_invokes_public_filter_methods
-    strainer = StrainerFactory.create(@context)
+    strainer = @environment.create_strainer(@context)
     assert_equal(false, strainer.class.invokable?('__test__'))
     assert_equal(false, strainer.class.invokable?('test'))
     assert_equal(false, strainer.class.invokable?('instance_eval'))
@@ -66,18 +69,18 @@ class StrainerFactoryUnitTest < Minitest::Test
   end
 
   def test_strainer_returns_nil_if_no_filter_method_found
-    strainer = StrainerFactory.create(@context)
+    strainer = @environment.create_strainer(@context)
     assert_nil(strainer.invoke("private_filter"))
     assert_nil(strainer.invoke("undef_the_filter"))
   end
 
   def test_strainer_returns_first_argument_if_no_method_and_arguments_given
-    strainer = StrainerFactory.create(@context)
+    strainer = @environment.create_strainer(@context)
     assert_equal("password", strainer.invoke("undef_the_method", "password"))
   end
 
   def test_strainer_only_allows_methods_defined_in_filters
-    strainer = StrainerFactory.create(@context)
+    strainer = @environment.create_strainer(@context)
     assert_equal("1 + 1", strainer.invoke("instance_eval", "1 + 1"))
     assert_equal("puts",  strainer.invoke("__send__", "puts", "Hi Mom"))
     assert_equal("has_method?", strainer.invoke("invoke", "has_method?", "invoke"))
@@ -86,7 +89,9 @@ class StrainerFactoryUnitTest < Minitest::Test
   def test_strainer_uses_a_class_cache_to_avoid_method_cache_invalidation
     a = Module.new
     b = Module.new
-    strainer = StrainerFactory.create(@context, [a, b])
+
+    strainer = @environment.create_strainer(@context, [a, b])
+
     assert_kind_of(StrainerTemplate, strainer)
     assert_kind_of(a, strainer)
     assert_kind_of(b, strainer)
@@ -94,8 +99,10 @@ class StrainerFactoryUnitTest < Minitest::Test
   end
 
   def test_add_global_filter_clears_cache
-    assert_equal('input', StrainerFactory.create(@context).invoke('late_added_filter', 'input'))
-    StrainerFactory.add_global_filter(LateAddedFilter)
-    assert_equal('filtered', StrainerFactory.create(nil).invoke('late_added_filter', 'input'))
+    assert_equal('input', @environment.create_strainer(@context).invoke('late_added_filter', 'input'))
+
+    @environment.register_filter(LateAddedFilter)
+
+    assert_equal('filtered', @environment.create_strainer(nil).invoke('late_added_filter', 'input'))
   end
 end

test/unit/lexer_unit_test.rb

@@ -134,6 +134,6 @@ class LexerUnitTest < Minitest::Test
   private
 
   def tokenize(input)
-    Lexer.new(input).tokenize
+    Lexer.tokenize(StringScanner.new(input))
   end
 end

test/unit/parser_unit_test.rb

@@ -6,20 +6,20 @@ class ParserUnitTest < Minitest::Test
   include Liquid
 
   def test_consume
-    p = Parser.new("wat: 7")
+    p = new_parser("wat: 7")
     assert_equal('wat', p.consume(:id))
     assert_equal(':', p.consume(:colon))
     assert_equal('7', p.consume(:number))
   end
 
   def test_jump
-    p = Parser.new("wat: 7")
+    p = new_parser("wat: 7")
     p.jump(2)
     assert_equal('7', p.consume(:number))
   end
 
   def test_consume?
-    p = Parser.new("wat: 7")
+    p = new_parser("wat: 7")
     assert_equal('wat', p.consume?(:id))
     assert_equal(false, p.consume?(:dot))
     assert_equal(':', p.consume(:colon))
@@ -27,7 +27,7 @@ class ParserUnitTest < Minitest::Test
   end
 
   def test_id?
-    p = Parser.new("wat 6 Peter Hegemon")
+    p = new_parser("wat 6 Peter Hegemon")
     assert_equal('wat', p.id?('wat'))
     assert_equal(false, p.id?('endgame'))
     assert_equal('6', p.consume(:number))
@@ -36,7 +36,7 @@ class ParserUnitTest < Minitest::Test
   end
 
   def test_look
-    p = Parser.new("wat 6 Peter Hegemon")
+    p = new_parser("wat 6 Peter Hegemon")
     assert_equal(true, p.look(:id))
     assert_equal('wat', p.consume(:id))
     assert_equal(false, p.look(:comparison))
@@ -46,12 +46,12 @@ class ParserUnitTest < Minitest::Test
   end
 
   def test_expressions
-    p = Parser.new("hi.there hi?[5].there? hi.there.bob")
+    p = new_parser("hi.there hi?[5].there? hi.there.bob")
     assert_equal('hi.there', p.expression)
     assert_equal('hi?[5].there?', p.expression)
     assert_equal('hi.there.bob', p.expression)
 
-    p = Parser.new("567 6.0 'lol' \"wut\"")
+    p = new_parser("567 6.0 'lol' \"wut\"")
     assert_equal('567', p.expression)
     assert_equal('6.0', p.expression)
     assert_equal("'lol'", p.expression)
@@ -59,7 +59,7 @@ class ParserUnitTest < Minitest::Test
   end
 
   def test_ranges
-    p = Parser.new("(5..7) (1.5..9.6) (young..old) (hi[5].wat..old)")
+    p = new_parser("(5..7) (1.5..9.6) (young..old) (hi[5].wat..old)")
     assert_equal('(5..7)', p.expression)
     assert_equal('(1.5..9.6)', p.expression)
     assert_equal('(young..old)', p.expression)
@@ -67,7 +67,7 @@ class ParserUnitTest < Minitest::Test
   end
 
   def test_arguments
-    p = Parser.new("filter: hi.there[5], keyarg: 7")
+    p = new_parser("filter: hi.there[5], keyarg: 7")
     assert_equal('filter', p.consume(:id))
     assert_equal(':', p.consume(:colon))
     assert_equal('hi.there[5]', p.argument)
@@ -77,8 +77,14 @@ class ParserUnitTest < Minitest::Test
 
   def test_invalid_expression
     assert_raises(SyntaxError) do
-      p = Parser.new("==")
+      p = new_parser("==")
       p.expression
     end
   end
+
+  private
+
+  def new_parser(str)
+    Parser.new(StringScanner.new(str))
+  end
 end

test/unit/strainer_template_unit_test.rb

@@ -25,11 +25,13 @@ class StrainerTemplateUnitTest < Minitest::Test
   end
 
   def test_add_filter_raises_when_module_privately_overrides_registered_public_methods
-    strainer = Context.new.strainer
-
     error = assert_raises(Liquid::MethodOverrideError) do
-      strainer.class.add_filter(PrivateMethodOverrideFilter)
+      Liquid::Environment.build do |env|
+        env.register_filter(PublicMethodOverrideFilter)
+        env.register_filter(PrivateMethodOverrideFilter)
+      end
     end
+
     assert_equal('Liquid error: Filter overrides registered public methods as non public: public_filter', error.message)
   end
 
@@ -42,11 +44,13 @@ class StrainerTemplateUnitTest < Minitest::Test
   end
 
   def test_add_filter_raises_when_module_overrides_registered_public_method_as_protected
-    strainer = Context.new.strainer
-
     error = assert_raises(Liquid::MethodOverrideError) do
-      strainer.class.add_filter(ProtectedMethodOverrideFilter)
+      Liquid::Environment.build do |env|
+        env.register_filter(PublicMethodOverrideFilter)
+        env.register_filter(ProtectedMethodOverrideFilter)
+      end
     end
+
     assert_equal('Liquid error: Filter overrides registered public methods as non public: public_filter', error.message)
   end
 

test/unit/tag_unit_test.rb

@@ -6,18 +6,18 @@ class TagUnitTest < Minitest::Test
   include Liquid
 
   def test_tag
-    tag = Tag.parse('tag', "", Tokenizer.new(""), ParseContext.new)
+    tag = Tag.parse('tag', "", new_tokenizer, ParseContext.new)
     assert_equal('liquid::tag', tag.name)
     assert_equal('', tag.render(Context.new))
   end
 
   def test_return_raw_text_of_tag
-    tag = Tag.parse("long_tag", "param1, param2, param3", Tokenizer.new(""), ParseContext.new)
+    tag = Tag.parse("long_tag", "param1, param2, param3", new_tokenizer, ParseContext.new)
     assert_equal("long_tag param1, param2, param3", tag.raw)
   end
 
   def test_tag_name_should_return_name_of_the_tag
-    tag = Tag.parse("some_tag", "", Tokenizer.new(""), ParseContext.new)
+    tag = Tag.parse("some_tag", "", new_tokenizer, ParseContext.new)
     assert_equal('some_tag', tag.tag_name)
   end
 
@@ -26,7 +26,16 @@ class TagUnitTest < Minitest::Test
   end
 
   def test_tag_render_to_output_buffer_nil_value
-    custom_tag = CustomTag.parse("some_tag", "", Tokenizer.new(""), ParseContext.new)
+    custom_tag = CustomTag.parse("some_tag", "", new_tokenizer, ParseContext.new)
     assert_equal('some string', custom_tag.render_to_output_buffer(Context.new, "some string"))
   end
+
+  private
+
+  def new_tokenizer
+    Tokenizer.new(
+      source: "",
+      string_scanner: StringScanner.new(""),
+    )
+  end
 end

test/unit/template_unit_test.rb

@@ -20,25 +20,6 @@ class TemplateUnitTest < Minitest::Test
     assert_equal(fixture("en_locale.yml"), locale.path)
   end
 
-  def test_with_cache_classes_tags_returns_the_same_class
-    original_cache_setting = Liquid.cache_classes
-    Liquid.cache_classes   = true
-
-    original_klass = Class.new
-    Object.send(:const_set, :CustomTag, original_klass)
-    Template.register_tag('custom', CustomTag)
-
-    Object.send(:remove_const, :CustomTag)
-
-    new_klass = Class.new
-    Object.send(:const_set, :CustomTag, new_klass)
-
-    assert(Template.tags['custom'].equal?(original_klass))
-  ensure
-    Object.send(:remove_const, :CustomTag)
-    Liquid.cache_classes = original_cache_setting
-  end
-
   class FakeTag; end
 
   def test_tags_can_be_looped_over

test/unit/tokenizer_unit_test.rb

@@ -6,6 +6,7 @@ class TokenizerTest < Minitest::Test
   def test_tokenize_strings
     assert_equal([' '], tokenize(' '))
     assert_equal(['hello world'], tokenize('hello world'))
+    assert_equal(['{}'], tokenize('{}'))
   end
 
   def test_tokenize_variables
@@ -30,6 +31,23 @@ class TokenizerTest < Minitest::Test
     assert_equal([1, 1, 3], tokenize_line_numbers(" {{\n funk \n}} "))
   end
 
+  def test_tokenize_with_nil_source_returns_empty_array
+    assert_equal([], tokenize(nil))
+  end
+
+  def test_incomplete_curly_braces
+    assert_equal(["{{.}", " "], tokenize('{{.} '))
+    assert_equal(["{{}", "%}"], tokenize('{{}%}'))
+    assert_equal(["{{}}", "}"], tokenize('{{}}}'))
+  end
+
+  def test_unmatching_start_and_end
+    assert_equal(["{{%}"], tokenize('{{%}'))
+    assert_equal(["{{%%%}}"], tokenize('{{%%%}}'))
+    assert_equal(["{%", "}}"], tokenize('{%}}'))
+    assert_equal(["{%%}", "}"], tokenize('{%%}}'))
+  end
+
   private
 
   def new_tokenizer(source, parse_context: Liquid::ParseContext.new, start_line_number: nil)