Shortcut for for statement

.gitignore

@@ -7,4 +7,3 @@ pkg
 .ruby-version
 Gemfile.lock
 .bundle
-.byebug_history

.rubocop.yml

@@ -1,16 +1,131 @@
 inherit_from:
-  - 'https://shopify.github.io/ruby-style-guide/rubocop.yml'
   - .rubocop_todo.yml
-
-require: rubocop-performance
-
-Performance:
-  Enabled: true
+  - ./.rubocop_todo.yml
 
 AllCops:
-  TargetRubyVersion: 2.4
   Exclude:
-    - 'vendor/bundle/**/*'
+    - 'performance/shopify/*'
+    - 'pkg/**'
+
+Metrics/BlockNesting:
+  Max: 3
+
+Metrics/ModuleLength:
+  Enabled: false
+
+Metrics/ClassLength:
+  Enabled: false
+
+Lint/AssignmentInCondition:
+  Enabled: false
+
+Lint/AmbiguousOperator:
+  Enabled: false
+
+Lint/AmbiguousRegexpLiteral:
+  Enabled: false
+
+Lint/ParenthesesAsGroupedExpression:
+  Enabled: false
+
+Lint/UnusedBlockArgument:
+  Enabled: false
+
+Layout/EndAlignment:
+  EnforcedStyleAlignWith: variable
+
+Lint/UnusedMethodArgument:
+  Enabled: false
+
+Style/SingleLineBlockParams:
+  Enabled: false
+
+Style/DoubleNegation:
+  Enabled: false
+
+Style/StringLiteralsInInterpolation:
+  Enabled: false
+
+Style/AndOr:
+  Enabled: false
+
+Style/SignalException:
+  Enabled: false
+
+Style/StringLiterals:
+  Enabled: false
+
+Style/BracesAroundHashParameters:
+  Enabled: false
+
+Style/NumericLiterals:
+  Enabled: false
+
+Layout/SpaceInsideArrayLiteralBrackets:
+  Enabled: false
+
+Layout/SpaceBeforeBlockBraces:
+  Enabled: false
+
+Style/Documentation:
+  Enabled: false
+
+Style/ClassAndModuleChildren:
+  Enabled: false
+
+Style/TrailingCommaInArrayLiteral:
+  Enabled: false
+
+Style/TrailingCommaInHashLiteral:
+  Enabled: false
+
+Layout/IndentHash:
+  EnforcedStyle: consistent
+
+Style/FormatString:
+  Enabled: false
+
+Layout/AlignParameters:
+  EnforcedStyle: with_fixed_indentation
+
+Layout/MultilineOperationIndentation:
+  EnforcedStyle: indented
+
+Style/IfUnlessModifier:
+  Enabled: false
+
+Style/RaiseArgs:
+  Enabled: false
+
+Style/PreferredHashMethods:
+  Enabled: false
+
+Style/RegexpLiteral:
+  Enabled: false
+
+Style/SymbolLiteral:
+  Enabled: false
+
+Performance/Count:
+  Enabled: false
+
+Naming/ConstantName:
+  Enabled: false
+
+Layout/CaseIndentation:
+  Enabled: false
+
+Style/ClassVars:
+  Enabled: false
+
+Style/PerlBackrefs:
+  Enabled: false
+
+Style/TrivialAccessors:
+  AllowPredicates: true
+
+Style/WordArray:
+  Enabled: false
 
 Naming/MethodName:
   Exclude:

.rubocop_todo.yml

@@ -1,11 +1,37 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2019-09-11 06:34:25 +1000 using RuboCop version 0.74.0.
+# on 2019-03-19 11:04:37 -0400 using RuboCop version 0.53.0.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
 # versions of RuboCop, may require this file to be generated again.
 
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: Include, TreatCommentsAsGroupSeparators.
+# Include: **/*.gemspec
+Gemspec/OrderedDependencies:
+  Exclude:
+    - 'liquid.gemspec'
+
+# Offense count: 5
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: auto_detection, squiggly, active_support, powerpack, unindent
+Layout/IndentHeredoc:
+  Exclude:
+    - 'test/integration/tags/for_tag_test.rb'
+    - 'test/integration/trim_mode_test.rb'
+
+# Offense count: 6
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: symmetrical, new_line, same_line
+Layout/MultilineMethodCallBraceLayout:
+  Exclude:
+    - 'test/integration/error_handling_test.rb'
+    - 'test/unit/strainer_unit_test.rb'
+
 # Offense count: 2
 # Cop supports --auto-correct.
 # Configuration parameters: EnforcedStyle.
@@ -14,35 +40,221 @@ Lint/InheritException:
   Exclude:
     - 'lib/liquid/interrupts.rb'
 
-# Offense count: 98
-# Cop supports --auto-correct.
-# Configuration parameters: AutoCorrect, AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
-# URISchemes: http, https
-Metrics/LineLength:
-  Max: 294
-
-# Offense count: 44
-Naming/ConstantName:
+# Offense count: 1
+# Configuration parameters: CheckForMethodsWithNoSideEffects.
+Lint/Void:
+  Exclude:
+    - 'lib/liquid/parse_context.rb'
+
+# Offense count: 54
+Metrics/AbcSize:
+  Max: 56
+
+# Offense count: 12
+Metrics/CyclomaticComplexity:
+  Max: 12
+
+# Offense count: 112
+# Configuration parameters: CountComments.
+Metrics/MethodLength:
+  Max: 37
+
+# Offense count: 8
+Metrics/PerceivedComplexity:
+  Max: 11
+
+# Offense count: 52
+# Configuration parameters: Blacklist.
+# Blacklist: END, (?-mix:EO[A-Z]{1})
+Naming/HeredocDelimiterNaming:
+  Exclude:
+    - 'test/integration/assign_test.rb'
+    - 'test/integration/capture_test.rb'
+    - 'test/integration/trim_mode_test.rb'
+
+# Offense count: 23
+# Configuration parameters: MinNameLength, AllowNamesEndingInNumbers, AllowedNames, ForbiddenNames.
+# AllowedNames: io, id
+Naming/UncommunicativeMethodParamName:
+  Exclude:
+    - 'example/server/example_servlet.rb'
+    - 'lib/liquid/condition.rb'
+    - 'lib/liquid/context.rb'
+    - 'lib/liquid/standardfilters.rb'
+    - 'lib/liquid/tags/if.rb'
+    - 'lib/liquid/utils.rb'
+    - 'lib/liquid/variable.rb'
+    - 'test/integration/filter_test.rb'
+    - 'test/integration/standard_filter_test.rb'
+    - 'test/integration/tags/for_tag_test.rb'
+    - 'test/integration/template_test.rb'
+    - 'test/unit/condition_unit_test.rb'
+
+# Offense count: 10
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: prefer_alias, prefer_alias_method
+Style/Alias:
+  Exclude:
+    - 'lib/liquid/drop.rb'
+    - 'lib/liquid/i18n.rb'
+    - 'lib/liquid/profiler/hooks.rb'
+    - 'lib/liquid/standardfilters.rb'
+    - 'lib/liquid/tag.rb'
+    - 'lib/liquid/tags/include.rb'
+    - 'lib/liquid/variable.rb'
+
+# Offense count: 22
+Style/CommentedKeyword:
+  Enabled: false
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle, SingleLineConditionsOnly, IncludeTernaryExpressions.
+# SupportedStyles: assign_to_condition, assign_inside_condition
+Style/ConditionalAssignment:
+  Exclude:
+    - 'lib/liquid/errors.rb'
+
+# Offense count: 1
+Style/DateTime:
+  Exclude:
+    - 'test/unit/context_unit_test.rb'
+
+# Offense count: 2
+# Cop supports --auto-correct.
+Style/EmptyCaseCondition:
   Exclude:
-    - 'lib/liquid.rb'
     - 'lib/liquid/block_body.rb'
+    - 'lib/liquid/lexer.rb'
+
+# Offense count: 5
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: compact, expanded
+Style/EmptyMethod:
+  Exclude:
+    - 'lib/liquid/tag.rb'
+    - 'lib/liquid/tags/comment.rb'
+    - 'lib/liquid/tags/include.rb'
+    - 'test/integration/tags/include_tag_test.rb'
+    - 'test/unit/context_unit_test.rb'
+
+# Offense count: 3
+# Cop supports --auto-correct.
+Style/Encoding:
+  Exclude:
+    - 'lib/liquid/version.rb'
+    - 'liquid.gemspec'
+    - 'test/integration/standard_filter_test.rb'
+
+# Offense count: 2
+# Cop supports --auto-correct.
+Style/ExpandPathArguments:
+  Exclude:
+    - 'Rakefile'
+    - 'liquid.gemspec'
+
+# Offense count: 7
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: annotated, template, unannotated
+Style/FormatStringToken:
+  Exclude:
+    - 'test/integration/filter_test.rb'
+    - 'test/integration/hash_ordering_test.rb'
+
+# Offense count: 14
+# Configuration parameters: MinBodyLength.
+Style/GuardClause:
+  Exclude:
+    - 'lib/liquid/condition.rb'
+    - 'lib/liquid/lexer.rb'
+    - 'lib/liquid/strainer.rb'
     - 'lib/liquid/tags/assign.rb'
     - 'lib/liquid/tags/capture.rb'
     - 'lib/liquid/tags/case.rb'
-    - 'lib/liquid/tags/cycle.rb'
     - 'lib/liquid/tags/for.rb'
-    - 'lib/liquid/tags/if.rb'
     - 'lib/liquid/tags/include.rb'
     - 'lib/liquid/tags/raw.rb'
     - 'lib/liquid/tags/table_row.rb'
     - 'lib/liquid/variable.rb'
-    - 'performance/shopify/comment_form.rb'
-    - 'performance/shopify/paginate.rb'
-    - 'test/integration/tags/include_tag_test.rb'
+    - 'test/unit/tokenizer_unit_test.rb'
 
-# Offense count: 5
-Style/ClassVars:
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle, MinBodyLength.
+# SupportedStyles: skip_modifier_ifs, always
+Style/Next:
+  Exclude:
+    - 'lib/liquid/tags/for.rb'
+
+# Offense count: 4
+# Cop supports --auto-correct.
+# Configuration parameters: AutoCorrect, EnforcedStyle.
+# SupportedStyles: predicate, comparison
+Style/NumericPredicate:
+  Exclude:
+    - 'spec/**/*'
+    - 'lib/liquid/context.rb'
+    - 'lib/liquid/forloop_drop.rb'
+    - 'lib/liquid/standardfilters.rb'
+    - 'lib/liquid/tablerowloop_drop.rb'
+
+# Offense count: 14
+# Cop supports --auto-correct.
+# Configuration parameters: PreferredDelimiters.
+Style/PercentLiteralDelimiters:
+  Exclude:
+    - 'lib/liquid/tags/if.rb'
+    - 'liquid.gemspec'
+    - 'test/integration/assign_test.rb'
+    - 'test/integration/standard_filter_test.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Style/RedundantSelf:
   Exclude:
-    - 'lib/liquid/condition.rb'
     - 'lib/liquid/strainer.rb'
-    - 'lib/liquid/template.rb'
+
+# Offense count: 9
+# Cop supports --auto-correct.
+# Configuration parameters: AllowAsExpressionSeparator.
+Style/Semicolon:
+  Exclude:
+    - 'test/integration/error_handling_test.rb'
+    - 'test/integration/template_test.rb'
+    - 'test/unit/context_unit_test.rb'
+
+# Offense count: 7
+# Cop supports --auto-correct.
+# Configuration parameters: MinSize.
+# SupportedStyles: percent, brackets
+Style/SymbolArray:
+  EnforcedStyle: brackets
+
+# Offense count: 2
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle, AllowSafeAssignment.
+# SupportedStyles: require_parentheses, require_no_parentheses, require_parentheses_when_complex
+Style/TernaryParentheses:
+  Exclude:
+    - 'lib/liquid/context.rb'
+    - 'lib/liquid/utils.rb'
+
+# Offense count: 2
+# Cop supports --auto-correct.
+Style/UnneededPercentQ:
+  Exclude:
+    - 'test/integration/error_handling_test.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Style/WhileUntilModifier:
+  Exclude:
+    - 'lib/liquid/tags/case.rb'
+
+# Offense count: 640
+# Configuration parameters: AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
+# URISchemes: http, https
+Metrics/LineLength:
+  Max: 294

.travis.yml

@@ -1,26 +1,31 @@
 language: ruby
-cache: bundler
 
 rvm:
+  - 2.1
+  - 2.2
+  - 2.3
   - 2.4
   - 2.5
-  - &latest_ruby 2.6
-  - 2.7
   - ruby-head
+  - jruby-head
+#  - rbx-2
+
+sudo: false
+
+addons:
+  apt:
+    packages:
+    - libgmp3-dev
 
 matrix:
-  include:
-    - rvm: *latest_ruby
-      script: bundle exec rake memory_profile:run
-      name: Profiling Memory Usage
   allow_failures:
     - rvm: ruby-head
+    - rvm: jruby-head
 
-branches:
-  only:
-    - master
-    - gh-pages
-    - /.*-stable/
+install:
+  - bundle install
+
+script: bundle exec rake
 
 notifications:
   disable: true

Gemfile

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 source 'https://rubygems.org'
 git_source(:github) do |repo_name|
   "https://github.com/#{repo_name}.git"
@@ -10,18 +8,16 @@ gemspec
 group :benchmark, :test do
   gem 'benchmark-ips'
   gem 'memory_profiler'
-  gem 'terminal-table'
 
-  install_if -> { RUBY_PLATFORM !~ /mingw|mswin|java/ && RUBY_ENGINE != 'truffleruby' } do
+  install_if -> { RUBY_PLATFORM !~ /mingw|mswin|java/ } do
     gem 'stackprof'
   end
 end
 
 group :test do
-  gem 'rubocop', '~> 0.74.0', require: false
-  gem 'rubocop-performance', require: false
+  gem 'rubocop', '~> 0.53.0'
 
-  platform :mri, :truffleruby do
-    gem 'liquid-c', github: 'Shopify/liquid-c', ref: 'master'
+  platform :mri do
+    gem 'liquid-c', github: 'Shopify/liquid-c', ref: '9168659de45d6d576fce30c735f857e597fa26f6'
   end
 end

README.md

@@ -106,9 +106,3 @@ template = Liquid::Template.parse("{{x}} {{y}}")
 template.render!({ 'x' => 1}, { strict_variables: true })
 #=> Liquid::UndefinedVariable: Liquid error: undefined variable y
 ```
-
-### Usage tracking
-
-To help track usages of a feature or code path in production, we have released opt-in usage tracking. To enable this, we provide an empty `Liquid:: Usage.increment` method which you can customize to your needs. The feature is well suited to https://github.com/Shopify/statsd-instrument. However, the choice of implementation is up to you.
-
-Once you have enabled usage tracking, we recommend reporting any events through Github Issues that your system may be logging. It is highly likely this event has been added to consider deprecating or improving code specific to this event, so please raise any concerns.

Rakefile

@@ -1,33 +1,29 @@
-# frozen_string_literal: true
-
 require 'rake'
 require 'rake/testtask'
-$LOAD_PATH.unshift(File.expand_path("../lib", __FILE__))
+$LOAD_PATH.unshift File.expand_path("../lib", __FILE__)
 require "liquid/version"
 
-task(default: [:test, :rubocop])
+task default: [:test, :rubocop]
 
-desc('run test suite with default parser')
+desc 'run test suite with default parser'
 Rake::TestTask.new(:base_test) do |t|
   t.libs << '.' << 'lib' << 'test'
   t.test_files = FileList['test/{integration,unit}/**/*_test.rb']
   t.verbose = false
 end
 
-desc('run test suite with warn error mode')
+desc 'run test suite with warn error mode'
 task :warn_test do
   ENV['LIQUID_PARSER_MODE'] = 'warn'
   Rake::Task['base_test'].invoke
 end
 
 task :rubocop do
-  if RUBY_ENGINE == 'ruby'
-    require 'rubocop/rake_task'
-    RuboCop::RakeTask.new
-  end
+  require 'rubocop/rake_task'
+  RuboCop::RakeTask.new
 end
 
-desc('runs test suite with both strict and lax parsers')
+desc 'runs test suite with both strict and lax parsers'
 task :test do
   ENV['LIQUID_PARSER_MODE'] = 'lax'
   Rake::Task['base_test'].invoke
@@ -36,8 +32,8 @@ task :test do
   Rake::Task['base_test'].reenable
   Rake::Task['base_test'].invoke
 
-  if RUBY_ENGINE == 'ruby' || RUBY_ENGINE == 'truffleruby'
-    ENV['LIQUID_C'] = '1'
+  if RUBY_ENGINE == 'ruby'
+    ENV['LIQUID-C'] = '1'
 
     ENV['LIQUID_PARSER_MODE'] = 'lax'
     Rake::Task['base_test'].reenable
@@ -49,7 +45,7 @@ task :test do
   end
 end
 
-task(gem: :build)
+task gem: :build
 task :build do
   system "gem build liquid.gemspec"
 end
@@ -96,7 +92,7 @@ namespace :memory_profile do
   end
 end
 
-desc("Run example")
+desc "Run example"
 task :example do
   ruby "-w -d -Ilib example/server/server.rb"
 end

example/server/example_servlet.rb

@@ -1,8 +1,6 @@
-# frozen_string_literal: true
-
 module ProductsFilter
   def price(integer)
-    format("$%.2d USD", integer / 100.0)
+    sprintf("$%.2d USD", integer / 100.0)
   end
 
   def prettyprint(text)

example/server/liquid_servlet.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 class LiquidServlet < WEBrick::HTTPServlet::AbstractServlet
   def do_GET(req, res)
     handle(:get, req, res)
@@ -11,12 +9,12 @@ class LiquidServlet < WEBrick::HTTPServlet::AbstractServlet
 
   private
 
-  def handle(_type, req, res)
+  def handle(type, req, res)
     @request = req
     @response = res
 
     @request.path_info =~ /(\w+)\z/
-    @action = Regexp.last_match(1) || 'index'
+    @action = $1 || 'index'
     @assigns = send(@action) if respond_to?(@action)
 
     @response['Content-Type'] = "text/html"

example/server/server.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'webrick'
 require 'rexml/document'
 
@@ -10,5 +8,5 @@ require_relative 'example_servlet'
 # Setup webrick
 server = WEBrick::HTTPServer.new(Port: ARGV[1] || 3000)
 server.mount('/', Servlet)
-trap("INT") { server.shutdown }
+trap("INT"){ server.shutdown }
 server.start

lib/liquid.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 # Copyright (c) 2005 Tobias Luetke
 #
 # Permission is hereby granted, free of charge, to any person obtaining
@@ -23,10 +21,10 @@
 
 module Liquid
   FilterSeparator             = /\|/
-  ArgumentSeparator           = ','
-  FilterArgumentSeparator     = ':'
-  VariableAttributeSeparator  = '.'
-  WhitespaceControl           = '-'
+  ArgumentSeparator           = ','.freeze
+  FilterArgumentSeparator     = ':'.freeze
+  VariableAttributeSeparator  = '.'.freeze
+  WhitespaceControl           = '-'.freeze
   TagStart                    = /\{\%/
   TagEnd                      = /\%\}/
   VariableSignature           = /\(?[\w\-\.\[\]]\)?/
@@ -76,9 +74,6 @@ require 'liquid/condition'
 require 'liquid/utils'
 require 'liquid/tokenizer'
 require 'liquid/parse_context'
-require 'liquid/partial_cache'
-require 'liquid/usage'
-require 'liquid/static_registers'
 
 # Load all the tags of the standard library
 #

lib/liquid/block.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   class Block < Tag
     MAX_DEPTH = 100
@@ -15,7 +13,6 @@ module Liquid
       end
     end
 
-    # For backwards compatibility
     def render(context)
       @body.render(context)
     end
@@ -29,16 +26,16 @@ module Liquid
     end
 
     def unknown_tag(tag, _params, _tokens)
-      if tag == 'else'
-        raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_else",
-          block_name: block_name)
-      elsif tag.start_with?('end')
-        raise SyntaxError, parse_context.locale.t("errors.syntax.invalid_delimiter",
+      if tag == 'else'.freeze
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unexpected_else".freeze,
+          block_name: block_name))
+      elsif tag.start_with?('end'.freeze)
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.invalid_delimiter".freeze,
           tag: tag,
           block_name: block_name,
-          block_delimiter: block_delimiter)
+          block_delimiter: block_delimiter))
       else
-        raise SyntaxError, parse_context.locale.t("errors.syntax.unknown_tag", tag: tag)
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unknown_tag".freeze, tag: tag))
       end
     end
 
@@ -54,7 +51,7 @@ module Liquid
 
     def parse_body(body, tokens)
       if parse_context.depth >= MAX_DEPTH
-        raise StackLevelError, "Nesting too deep"
+        raise StackLevelError, "Nesting too deep".freeze
       end
       parse_context.depth += 1
       begin
@@ -63,7 +60,7 @@ module Liquid
 
           return false if end_tag_name == block_delimiter
           unless end_tag_name
-            raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed", block_name: block_name)
+            raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_never_closed".freeze, block_name: block_name))
           end
 
           # this tag is not registered with the system

lib/liquid/block_body.rb

@@ -1,13 +1,10 @@
-# frozen_string_literal: true
-
 module Liquid
   class BlockBody
-    LiquidTagToken = /\A\s*(\w+)\s*(.*?)\z/o
-    FullToken = /\A#{TagStart}#{WhitespaceControl}?(\s*)(\w+)(\s*)(.*?)#{WhitespaceControl}?#{TagEnd}\z/om
+    FullToken = /\A#{TagStart}#{WhitespaceControl}?\s*(\w+)\s*(.*?)#{WhitespaceControl}?#{TagEnd}\z/om
     ContentOfVariable = /\A#{VariableStart}#{WhitespaceControl}?(.*?)#{WhitespaceControl}?#{VariableEnd}\z/om
     WhitespaceOrNothing = /\A\s*\z/
-    TAGSTART = "{%"
-    VARSTART = "{{"
+    TAGSTART = "{%".freeze
+    VARSTART = "{{".freeze
 
     attr_reader :nodelist
 
@@ -16,43 +13,9 @@ module Liquid
       @blank = true
     end
 
-    def parse(tokenizer, parse_context, &block)
+    def parse(tokenizer, parse_context)
       parse_context.line_number = tokenizer.line_number
-
-      if tokenizer.for_liquid_tag
-        parse_for_liquid_tag(tokenizer, parse_context, &block)
-      else
-        parse_for_document(tokenizer, parse_context, &block)
-      end
-    end
-
-    private def parse_for_liquid_tag(tokenizer, parse_context)
-      while (token = tokenizer.shift)
-        unless token.empty? || token =~ WhitespaceOrNothing
-          unless token =~ LiquidTagToken
-            # line isn't empty but didn't match tag syntax, yield and let the
-            # caller raise a syntax error
-            return yield token, token
-          end
-          tag_name = Regexp.last_match(1)
-          markup = Regexp.last_match(2)
-          unless (tag = registered_tags[tag_name])
-            # end parsing if we reach an unknown tag and let the caller decide
-            # determine how to proceed
-            return yield tag_name, markup
-          end
-          new_tag = tag.parse(tag_name, markup, tokenizer, parse_context)
-          @blank &&= new_tag.blank?
-          @nodelist << new_tag
-        end
-        parse_context.line_number = tokenizer.line_number
-      end
-
-      yield nil, nil
-    end
-
-    private def parse_for_document(tokenizer, parse_context, &block)
-      while (token = tokenizer.shift)
+      while token = tokenizer.shift
         next if token.empty?
         case
         when token.start_with?(TAGSTART)
@@ -60,21 +23,10 @@ module Liquid
           unless token =~ FullToken
             raise_missing_tag_terminator(token, parse_context)
           end
-          tag_name = Regexp.last_match(2)
-          markup = Regexp.last_match(4)
-
-          if parse_context.line_number
-            # newlines inside the tag should increase the line number,
-            # particularly important for multiline {% liquid %} tags
-            parse_context.line_number += Regexp.last_match(1).count("\n") + Regexp.last_match(3).count("\n")
-          end
-
-          if tag_name == 'liquid'
-            liquid_tag_tokenizer = Tokenizer.new(markup, line_number: parse_context.line_number, for_liquid_tag: true)
-            next parse_for_liquid_tag(liquid_tag_tokenizer, parse_context, &block)
-          end
-
-          unless (tag = registered_tags[tag_name])
+          tag_name = $1
+          markup = $2
+          # fetch the tag from registered blocks
+          unless tag = registered_tags[tag_name]
             # end parsing if we reach an unknown tag and let the caller decide
             # determine how to proceed
             return yield tag_name, markup
@@ -103,7 +55,7 @@ module Liquid
     def whitespace_handler(token, parse_context)
       if token[2] == WhitespaceControl
         previous_token = @nodelist.last
-        if previous_token.is_a?(String)
+        if previous_token.is_a? String
           previous_token.rstrip!
         end
       end
@@ -115,23 +67,19 @@ module Liquid
     end
 
     def render(context)
-      render_to_output_buffer(context, +'')
-    end
-
-    def render_to_output_buffer(context, output)
+      output = []
       context.resource_limits.render_score += @nodelist.length
 
       idx = 0
-      while (node = @nodelist[idx])
-        previous_output_size = output.bytesize
-
+      while node = @nodelist[idx]
         case node
         when String
+          check_resources(context, node)
           output << node
         when Variable
-          render_node(context, output, node)
+          render_node_to_output(node, output, context)
         when Block
-          render_node(context, node.blank? ? +'' : output, node)
+          render_node_to_output(node, output, context, node.blank?)
           break if context.interrupt? # might have happened in a for-block
         when Continue, Break
           # If we get an Interrupt that means the block must stop processing. An
@@ -140,32 +88,36 @@ module Liquid
           context.push_interrupt(node.interrupt)
           break
         else # Other non-Block tags
-          render_node(context, output, node)
+          render_node_to_output(node, output, context)
           break if context.interrupt? # might have happened through an include
         end
         idx += 1
-
-        raise_if_resource_limits_reached(context, output.bytesize - previous_output_size)
       end
 
-      output
+      output.join
     end
 
     private
 
-    def render_node(context, output, node)
-      node.render_to_output_buffer(context, output)
+    def render_node_to_output(node, output, context, skip_output = false)
+      node_output = node.render(context)
+      node_output = node_output.is_a?(Array) ? node_output.join : node_output.to_s
+      check_resources(context, node_output)
+      output << node_output unless skip_output
+    rescue MemoryError => e
+      raise e
     rescue UndefinedVariable, UndefinedDropMethod, UndefinedFilter => e
       context.handle_error(e, node.line_number)
+      output << nil
     rescue ::StandardError => e
       line_number = node.is_a?(String) ? nil : node.line_number
       output << context.handle_error(e, line_number)
     end
 
-    def raise_if_resource_limits_reached(context, length)
-      context.resource_limits.render_length += length
+    def check_resources(context, node_output)
+      context.resource_limits.render_length += node_output.bytesize
       return unless context.resource_limits.reached?
-      raise MemoryError, "Memory limits exceeded"
+      raise MemoryError.new("Memory limits exceeded".freeze)
     end
 
     def create_variable(token, parse_context)
@@ -177,11 +129,11 @@ module Liquid
     end
 
     def raise_missing_tag_terminator(token, parse_context)
-      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_termination", token: token, tag_end: TagEnd.inspect)
+      raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_termination".freeze, token: token, tag_end: TagEnd.inspect))
     end
 
     def raise_missing_variable_terminator(token, parse_context)
-      raise SyntaxError, parse_context.locale.t("errors.syntax.variable_termination", token: token, tag_end: VariableEnd.inspect)
+      raise SyntaxError.new(parse_context.locale.t("errors.syntax.variable_termination".freeze, token: token, tag_end: VariableEnd.inspect))
     end
 
     def registered_tags

lib/liquid/condition.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   # Container for liquid nodes which conveniently wraps decision making logic
   #
@@ -10,21 +8,21 @@ module Liquid
   #
   class Condition #:nodoc:
     @@operators = {
-      '==' => ->(cond, left, right) {  cond.send(:equal_variables, left, right) },
-      '!=' => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
-      '<>' => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
-      '<' => :<,
-      '>' => :>,
-      '>=' => :>=,
-      '<=' => :<=,
-      'contains' => lambda do |_cond, left, right|
+      '=='.freeze => ->(cond, left, right) {  cond.send(:equal_variables, left, right) },
+      '!='.freeze => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
+      '<>'.freeze => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
+      '<'.freeze  => :<,
+      '>'.freeze  => :>,
+      '>='.freeze => :>=,
+      '<='.freeze => :<=,
+      'contains'.freeze => lambda do |cond, left, right|
         if left && right && left.respond_to?(:include?)
           right = right.to_s if left.is_a?(String)
           left.include?(right)
         else
           false
         end
-      end,
+      end
     }
 
     def self.operators
@@ -38,7 +36,7 @@ module Liquid
       @left = left
       @operator = operator
       @right = right
-      @child_relation = nil
+      @child_relation  = nil
       @child_condition = nil
     end
 
@@ -80,7 +78,7 @@ module Liquid
     end
 
     def inspect
-      "#<Condition #{[@left, @operator, @right].compact.join(' ')}>"
+      "#<Condition #{[@left, @operator, @right].compact.join(' '.freeze)}>"
     end
 
     protected
@@ -118,7 +116,7 @@ module Liquid
       left = context.evaluate(left)
       right = context.evaluate(right)
 
-      operation = self.class.operators[op] || raise(Liquid::ArgumentError, "Unknown operator #{op}")
+      operation = self.class.operators[op] || raise(Liquid::ArgumentError.new("Unknown operator #{op}"))
 
       if operation.respond_to?(:call)
         operation.call(self, left, right)
@@ -126,7 +124,7 @@ module Liquid
         begin
           left.send(operation, right)
         rescue ::ArgumentError => e
-          raise Liquid::ArgumentError, e.message
+          raise Liquid::ArgumentError.new(e.message)
         end
       end
     end

lib/liquid/context.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   # Context keeps the variable stack and resolves variables, as well as keywords
   #
@@ -14,38 +12,30 @@ module Liquid
   #
   #   context['bob']  #=> nil  class Context
   class Context
-    attr_reader :scopes, :errors, :registers, :environments, :resource_limits, :static_registers, :static_environments
+    attr_reader :scope, :errors, :registers, :environments, :resource_limits
     attr_accessor :exception_renderer, :template_name, :partial, :global_filter, :strict_variables, :strict_filters
 
-    # rubocop:disable Metrics/ParameterLists
-    def self.build(environments: {}, outer_scope: {}, registers: {}, rethrow_errors: false, resource_limits: nil, static_environments: {})
-      new(environments, outer_scope, registers, rethrow_errors, resource_limits, static_environments)
-    end
-
-    def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil, static_environments = {})
-      @environments = [environments]
-      @environments.flatten!
-
-      @static_environments = [static_environments].flat_map(&:freeze).freeze
-      @scopes              = [(outer_scope || {})]
-      @registers           = registers
-      @errors              = []
-      @partial             = false
-      @strict_variables    = false
-      @resource_limits     = resource_limits || ResourceLimits.new(Template.default_resource_limits)
-      @base_scope_depth    = 0
+    def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil)
+      @environments     = [environments].flatten
+      @scope            = outer_scope || {}
+      @registers        = registers
+      @errors           = []
+      @partial          = false
+      @strict_variables = false
+      @resource_limits  = resource_limits || ResourceLimits.new(Template.default_resource_limits)
       squash_instance_assigns_with_environments
 
       self.exception_renderer = Template.default_exception_renderer
       if rethrow_errors
-        self.exception_renderer = ->(_e) { raise }
+        self.exception_renderer = ->(e) { raise }
       end
 
       @interrupts = []
       @filters = []
       @global_filter = nil
+
+      @stack_level = 0
     end
-    # rubocop:enable Metrics/ParameterLists
 
     def warnings
       @warnings ||= []
@@ -96,21 +86,9 @@ module Liquid
       strainer.invoke(method, *args).to_liquid
     end
 
-    # Push new local scope on the stack. use <tt>Context#stack</tt> instead
-    def push(new_scope = {})
-      @scopes.unshift(new_scope)
-      check_overflow
-    end
-
     # Merge a hash of variables in the current local scope
     def merge(new_scopes)
-      @scopes[0].merge!(new_scopes)
-    end
-
-    # Pop from the stack. use <tt>Context#stack</tt> instead
-    def pop
-      raise ContextError if @scopes.size == 1
-      @scopes.shift
+      new_scopes.each { |k, v| self[k] = v }
     end
 
     # Pushes a new local scope on the stack, pops it at the end of the block
@@ -121,39 +99,20 @@ module Liquid
     #   end
     #
     #   context['var]  #=> nil
-    def stack(new_scope = {})
-      push(new_scope)
-      yield
-    ensure
-      pop
-    end
+    def stack(*variable_names)
+      @stack_level += 1
+      raise StackLevelError, "Nesting too deep".freeze if @stack_level > Block::MAX_DEPTH
 
-    # Creates a new context inheriting resource limits, filters, environment etc.,
-    # but with an isolated scope.
-    def new_isolated_subcontext
-      check_overflow
-
-      Context.build(
-        resource_limits: resource_limits,
-        static_environments: static_environments,
-        registers: StaticRegisters.new(registers)
-      ).tap do |subcontext|
-        subcontext.base_scope_depth = base_scope_depth + 1
-        subcontext.exception_renderer = exception_renderer
-        subcontext.filters = @filters
-        subcontext.strainer = nil
-        subcontext.errors = errors
-        subcontext.warnings = warnings
+      begin
+        yield
+      ensure
+        @stack_level -= 1
       end
     end
 
-    def clear_instance_assigns
-      @scopes[0] = {}
-    end
-
     # Only allow String, Numeric, Hash, Array, Proc, Boolean or <tt>Liquid::Drop</tt>
     def []=(key, value)
-      @scopes[0][key] = value
+      (@scope[key] ||= [nil]) << value
     end
 
     # Look up variable, either resolve directly after considering the name. We can directly handle
@@ -168,6 +127,29 @@ module Liquid
       evaluate(Expression.parse(expression))
     end
 
+    def unset(key)
+      if @scope[key].size <= 1
+        @scope.delete(key)
+      else
+        @scope[key].pop
+      end
+    end
+
+    def set_root(key, val)
+      @scope[key] ||= []
+      @scope[key][0] = val
+    end
+
+    def set_level(key, val, int)
+      @scope[key] ||= []
+      @scope[key][int] = val
+    end
+
+    def create_level(key)
+      (@scope[key] ||= [nil]) << nil
+      @scope[key].size - 1
+    end
+
     def key?(key)
       self[key] != nil
     end
@@ -178,72 +160,50 @@ module Liquid
 
     # Fetches an object starting at the local scope and then moving up the hierachy
     def find_variable(key, raise_on_not_found: true)
-      # This was changed from find() to find_index() because this is a very hot
-      # path and find_index() is optimized in MRI to reduce object allocation
-      index = @scopes.find_index { |s| s.key?(key) }
+      trigger = false
+      value = @scope[key]
+      scope = @scope unless value.nil?
+      trigger = true unless value.nil?
 
-      variable = if index
-        lookup_and_evaluate(@scopes[index], key, raise_on_not_found: raise_on_not_found)
-      else
-        try_variable_find_in_environments(key, raise_on_not_found: raise_on_not_found)
+      if scope.nil?
+        index = @environments.find_index do |e|
+          variable = lookup_and_evaluate(e, key, raise_on_not_found: raise_on_not_found)
+          # When lookup returned a value OR there is no value but the lookup also did not raise
+          # then it is the value we are looking for.
+          !variable.nil? || @strict_variables && raise_on_not_found
+        end
+
+        scope = @environments[index || -1]
       end
 
+      variable ||= lookup_and_evaluate(scope, key, trigger, raise_on_not_found: raise_on_not_found)
+
       variable = variable.to_liquid
       variable.context = self if variable.respond_to?(:context=)
 
       variable
     end
 
-    def lookup_and_evaluate(obj, key, raise_on_not_found: true)
+    def lookup_and_evaluate(obj, key, trigger = false, raise_on_not_found: true)
       if @strict_variables && raise_on_not_found && obj.respond_to?(:key?) && !obj.key?(key)
         raise Liquid::UndefinedVariable, "undefined variable #{key}"
       end
 
-      value = obj[key]
+      value = if trigger == true
+        obj[key][-1]
+      else
+        obj[key]
+      end
 
       if value.is_a?(Proc) && obj.respond_to?(:[]=)
-        obj[key] = value.arity == 0 ? value.call : value.call(self)
+        obj[key] = (value.arity == 0) ? value.call : value.call(self)
       else
         value
       end
     end
 
-    protected
-
-    attr_writer :base_scope_depth, :warnings, :errors, :strainer, :filters
-
     private
 
-    attr_reader :base_scope_depth
-
-    def try_variable_find_in_environments(key, raise_on_not_found:)
-      @environments.each do |environment|
-        found_variable = lookup_and_evaluate(environment, key, raise_on_not_found: raise_on_not_found)
-        Usage.increment("environment_has_a_default_proc") if environment.respond_to?(:default_proc) && environment.default_proc
-        Usage.increment("environment_has_key_but_is_nil") if environment.respond_to?(:key?) && environment.key?(key) && found_variable.nil?
-        if !found_variable.nil? || @strict_variables && raise_on_not_found
-          return found_variable
-        end
-      end
-      @static_environments.each do |environment|
-        found_variable = lookup_and_evaluate(environment, key, raise_on_not_found: raise_on_not_found)
-        Usage.increment("static_environment_has_a_default_proc") if environment.respond_to?(:default_proc) && environment.default_proc
-        Usage.increment("static_environment_has_key_but_is_nil") if environment.respond_to?(:key?) && environment.key?(key) && found_variable.nil?
-        if !found_variable.nil? || @strict_variables && raise_on_not_found
-          return found_variable
-        end
-      end
-      nil
-    end
-
-    def check_overflow
-      raise StackLevelError, "Nesting too deep" if overflow?
-    end
-
-    def overflow?
-      base_scope_depth + @scopes.length > Block::MAX_DEPTH
-    end
-
     def internal_error
       # raise and catch to set backtrace and cause on exception
       raise Liquid::InternalError, 'internal'
@@ -252,10 +212,10 @@ module Liquid
     end
 
     def squash_instance_assigns_with_environments
-      @scopes.last.each_key do |k|
+      @scope.each_key do |k|
         @environments.each do |env|
           if env.key?(k)
-            scopes.last[k] = lookup_and_evaluate(env, k)
+            @scope[k] = [lookup_and_evaluate(env, k)]
             break
           end
         end

lib/liquid/document.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   class Document < BlockBody
     def self.parse(tokens, parse_context)
@@ -9,7 +7,7 @@ module Liquid
     end
 
     def parse(tokens, parse_context)
-      super do |end_tag_name, _end_tag_params|
+      super do |end_tag_name, end_tag_params|
         unknown_tag(end_tag_name, parse_context) if end_tag_name
       end
     rescue SyntaxError => e
@@ -19,10 +17,10 @@ module Liquid
 
     def unknown_tag(tag, parse_context)
       case tag
-      when 'else', 'end'
-        raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_outer_tag", tag: tag)
+      when 'else'.freeze, 'end'.freeze
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unexpected_outer_tag".freeze, tag: tag))
       else
-        raise SyntaxError, parse_context.locale.t("errors.syntax.unknown_tag", tag: tag)
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unknown_tag".freeze, tag: tag))
       end
     end
   end

lib/liquid/drop.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'set'
 
 module Liquid
@@ -27,7 +25,7 @@ module Liquid
 
     # Catch all for the method
     def liquid_method_missing(method)
-      return nil unless @context&.strict_variables
+      return nil unless @context && @context.strict_variables
       raise Liquid::UndefinedDropMethod, "undefined method #{method}"
     end
 
@@ -69,7 +67,7 @@ module Liquid
 
         if include?(Enumerable)
           blacklist += Enumerable.public_instance_methods
-          blacklist -= [:sort, :count, :first, :min, :max]
+          blacklist -= [:sort, :count, :first, :min, :max, :include?]
         end
 
         whitelist = [:to_liquid] + (public_instance_methods - blacklist)

lib/liquid/errors.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   class Error < ::StandardError
     attr_accessor :line_number
@@ -7,7 +5,7 @@ module Liquid
     attr_accessor :markup_context
 
     def to_s(with_prefix = true)
-      str = +""
+      str = ""
       str << message_prefix if with_prefix
       str << super()
 
@@ -22,11 +20,11 @@ module Liquid
     private
 
     def message_prefix
-      str = +""
-      str << if is_a?(SyntaxError)
-        "Liquid syntax error"
+      str = ""
+      if is_a?(SyntaxError)
+        str << "Liquid syntax error"
       else
-        "Liquid error"
+        str << "Liquid error"
       end
 
       if line_number

lib/liquid/expression.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   class Expression
     class MethodLiteral
@@ -16,11 +14,11 @@ module Liquid
     end
 
     LITERALS = {
-      nil => nil, 'nil' => nil, 'null' => nil, '' => nil,
-      'true' => true,
-      'false' => false,
-      'blank' => MethodLiteral.new(:blank?, '').freeze,
-      'empty' => MethodLiteral.new(:empty?, '').freeze
+      nil => nil, 'nil'.freeze => nil, 'null'.freeze => nil, ''.freeze => nil,
+      'true'.freeze  => true,
+      'false'.freeze => false,
+      'blank'.freeze => MethodLiteral.new(:blank?, '').freeze,
+      'empty'.freeze => MethodLiteral.new(:empty?, '').freeze
     }.freeze
 
     SINGLE_QUOTED_STRING = /\A'(.*)'\z/m
@@ -35,13 +33,13 @@ module Liquid
       else
         case markup
         when SINGLE_QUOTED_STRING, DOUBLE_QUOTED_STRING
-          Regexp.last_match(1)
+          $1
         when INTEGERS_REGEX
-          Regexp.last_match(1).to_i
+          $1.to_i
         when RANGES_REGEX
-          RangeLookup.parse(Regexp.last_match(1), Regexp.last_match(2))
+          RangeLookup.parse($1, $2)
         when FLOATS_REGEX
-          Regexp.last_match(1).to_f
+          $1.to_f
         else
           VariableLookup.parse(markup)
         end

lib/liquid/extensions.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'time'
 require 'date'
 

lib/liquid/file_system.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   # A Liquid file system is a way to let your templates retrieve other templates for use with the include tag.
   #
@@ -46,7 +44,7 @@ module Liquid
   class LocalFileSystem
     attr_accessor :root
 
-    def initialize(root, pattern = "_%s.liquid")
+    def initialize(root, pattern = "_%s.liquid".freeze)
       @root = root
       @pattern = pattern
     end
@@ -59,9 +57,9 @@ module Liquid
     end
 
     def full_path(template_path)
-      raise FileSystemError, "Illegal template name '#{template_path}'" unless %r{\A[^./][a-zA-Z0-9_/]+\z}.match?(template_path)
+      raise FileSystemError, "Illegal template name '#{template_path}'" unless template_path =~ /\A[^.\/][a-zA-Z0-9_\/]+\z/
 
-      full_path = if template_path.include?('/')
+      full_path = if template_path.include?('/'.freeze)
         File.join(root, File.dirname(template_path), @pattern % File.basename(template_path))
       else
         File.join(root, @pattern % template_path)

lib/liquid/forloop_drop.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   class ForloopDrop < Drop
     def initialize(name, length, parentloop)

lib/liquid/i18n.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'yaml'
 
 module Liquid
@@ -28,13 +26,13 @@ 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[$1.to_sym]).to_s
       end
     end
 
     def deep_fetch_translation(name)
-      name.split('.').reduce(locale) do |level, cur|
-        level[cur] || raise(TranslationError, "Translation for #{name} does not exist in locale #{path}")
+      name.split('.'.freeze).reduce(locale) do |level, cur|
+        level[cur] or raise TranslationError, "Translation for #{name} does not exist in locale #{path}"
       end
     end
   end

lib/liquid/interrupts.rb

@@ -1,12 +1,10 @@
-# frozen_string_literal: true
-
 module Liquid
   # An interrupt is any command that breaks processing of a block (ex: a for loop).
   class Interrupt
     attr_reader :message
 
     def initialize(message = nil)
-      @message = message || "interrupt"
+      @message = message || "interrupt".freeze
     end
   end
 

lib/liquid/lexer.rb

@@ -1,19 +1,17 @@
-# frozen_string_literal: true
-
 require "strscan"
 module Liquid
   class Lexer
     SPECIALS = {
-      '|' => :pipe,
-      '.' => :dot,
-      ':' => :colon,
-      ',' => :comma,
-      '[' => :open_square,
-      ']' => :close_square,
-      '(' => :open_round,
-      ')' => :close_round,
-      '?' => :question,
-      '-' => :dash,
+      '|'.freeze => :pipe,
+      '.'.freeze => :dot,
+      ':'.freeze => :colon,
+      ','.freeze => :comma,
+      '['.freeze => :open_square,
+      ']'.freeze => :close_square,
+      '('.freeze => :open_round,
+      ')'.freeze => :close_round,
+      '?'.freeze => :question,
+      '-'.freeze => :dash
     }.freeze
     IDENTIFIER = /[a-zA-Z_][\w-]*\??/
     SINGLE_STRING_LITERAL = /'[^\']*'/
@@ -33,21 +31,16 @@ module Liquid
       until @ss.eos?
         @ss.skip(WHITESPACE_OR_NOTHING)
         break if @ss.eos?
-        tok = if (t = @ss.scan(COMPARISON_OPERATOR))
-          [:comparison, t]
-        elsif (t = @ss.scan(SINGLE_STRING_LITERAL))
-          [:string, t]
-        elsif (t = @ss.scan(DOUBLE_STRING_LITERAL))
-          [:string, t]
-        elsif (t = @ss.scan(NUMBER_LITERAL))
-          [:number, t]
-        elsif (t = @ss.scan(IDENTIFIER))
-          [:id, t]
-        elsif (t = @ss.scan(DOTDOT))
-          [:dotdot, t]
+        tok = case
+        when t = @ss.scan(COMPARISON_OPERATOR) then [:comparison, t]
+        when t = @ss.scan(SINGLE_STRING_LITERAL) then [:string, t]
+        when t = @ss.scan(DOUBLE_STRING_LITERAL) then [:string, t]
+        when t = @ss.scan(NUMBER_LITERAL) then [:number, t]
+        when t = @ss.scan(IDENTIFIER) then [:id, t]
+        when t = @ss.scan(DOTDOT) then [:dotdot, t]
         else
           c = @ss.getch
-          if (s = SPECIALS[c])
+          if s = SPECIALS[c]
             [s, c]
           else
             raise SyntaxError, "Unexpected character #{c}"

lib/liquid/locales/en.yml

@@ -22,6 +22,5 @@
       tag_never_closed: "'%{block_name}' tag was never closed"
       meta_syntax_error: "Liquid syntax error: #{e.message}"
       table_row: "Syntax Error in 'table_row loop' - Valid syntax: table_row [item] in [collection] cols=3"
-      render: "Syntax error in tag 'render' - Template name must be a quoted string"
     argument:
       include: "Argument error in tag 'include' - Illegal template name"

lib/liquid/parse_context.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   class ParseContext
     attr_accessor :locale, :line_number, :trim_whitespace, :depth
@@ -21,6 +19,7 @@ module Liquid
       @partial = value
       @options = value ? partial_options : @template_options
       @error_mode = @options[:error_mode] || Template.error_mode
+      value
     end
 
     def partial_options
@@ -29,7 +28,7 @@ module Liquid
         if dont_pass == true
           { locale: locale }
         elsif dont_pass.is_a?(Array)
-          @template_options.reject { |k, _v| dont_pass.include?(k) }
+          @template_options.reject { |k, v| dont_pass.include?(k) }
         else
           @template_options
         end

lib/liquid/parse_tree_visitor.rb

@@ -28,7 +28,7 @@ module Liquid
         item, new_context = @callbacks[node.class].call(node, context)
         [
           item,
-          ParseTreeVisitor.for(node, @callbacks).visit(new_context || context),
+          ParseTreeVisitor.for(node, @callbacks).visit(new_context || context)
         ]
       end
     end

lib/liquid/parser.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   class Parser
     def initialize(input)
@@ -46,14 +44,11 @@ module Liquid
       tok[0] == type
     end
 
-    SINGLE_TOKEN_EXPRESSION_TYPES = [:string, :number].freeze
-    private_constant :SINGLE_TOKEN_EXPRESSION_TYPES
-
     def expression
       token = @tokens[@p]
       if token[0] == :id
         variable_signature
-      elsif SINGLE_TOKEN_EXPRESSION_TYPES.include?(token[0])
+      elsif [:string, :number].include? token[0]
         consume
       elsif token.first == :open_round
         consume
@@ -68,10 +63,10 @@ module Liquid
     end
 
     def argument
-      str = +""
+      str = ""
       # might be a keyword argument (identifier: expression)
       if look(:id) && look(:colon, 1)
-        str << consume << consume << ' '
+        str << consume << consume << ' '.freeze
       end
 
       str << expression

lib/liquid/parser_switching.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   module ParserSwitching
     def parse_with_selected_parser(markup)

lib/liquid/partial_cache.rb

@@ -1,20 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  class PartialCache
-    def self.load(template_name, context:, parse_context:)
-      cached_partials = (context.registers[:cached_partials] ||= {})
-      cached = cached_partials[template_name]
-      return cached if cached
-
-      file_system = (context.registers[:file_system] ||= Liquid::Template.file_system)
-      source = file_system.read_template_file(template_name)
-      parse_context.partial = true
-
-      partial = Liquid::Template.parse(source, parse_context)
-      cached_partials[template_name] = partial
-    ensure
-      parse_context.partial = false
-    end
-  end
-end

lib/liquid/profiler.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'liquid/profiler/hooks'
 
 module Liquid

lib/liquid/profiler/hooks.rb

@@ -1,25 +1,23 @@
-# frozen_string_literal: true
-
 module Liquid
   class BlockBody
-    def render_node_with_profiling(context, output, node)
+    def render_node_with_profiling(node, output, context, skip_output = false)
       Profiler.profile_node_render(node) do
-        render_node_without_profiling(context, output, node)
+        render_node_without_profiling(node, output, context, skip_output)
       end
     end
 
-    alias_method :render_node_without_profiling, :render_node
-    alias_method :render_node, :render_node_with_profiling
+    alias_method :render_node_without_profiling, :render_node_to_output
+    alias_method :render_node_to_output, :render_node_with_profiling
   end
 
   class Include < Tag
-    def render_to_output_buffer_with_profiling(context, output)
+    def render_with_profiling(context)
       Profiler.profile_children(context.evaluate(@template_name_expr).to_s) do
-        render_to_output_buffer_without_profiling(context, output)
+        render_without_profiling(context)
       end
     end
 
-    alias_method :render_to_output_buffer_without_profiling, :render_to_output_buffer
-    alias_method :render_to_output_buffer, :render_to_output_buffer_with_profiling
+    alias_method :render_without_profiling, :render
+    alias_method :render, :render_with_profiling
   end
 end

lib/liquid/range_lookup.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   class RangeLookup
     def self.parse(start_markup, end_markup)

lib/liquid/resource_limits.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   class ResourceLimits
     attr_accessor :render_length, :render_score, :assign_score,

lib/liquid/standardfilters.rb

@@ -1,22 +1,20 @@
-# frozen_string_literal: true
-
 require 'cgi'
 require 'bigdecimal'
 
 module Liquid
   module StandardFilters
     HTML_ESCAPE = {
-      '&' => '&',
-      '>' => '>',
-      '<' => '&lt;',
-      '"' => '&quot;',
-      "'" => '&#39;',
+      '&'.freeze => '&amp;'.freeze,
+      '>'.freeze => '&gt;'.freeze,
+      '<'.freeze => '&lt;'.freeze,
+      '"'.freeze => '&quot;'.freeze,
+      "'".freeze => '&#39;'.freeze
     }.freeze
     HTML_ESCAPE_ONCE_REGEXP = /["><']|&(?!([a-zA-Z]+|(#\d+));)/
     STRIP_HTML_BLOCKS = Regexp.union(
-      %r{<script.*?</script>}m,
+      /<script.*?<\/script>/m,
       /<!--.*?-->/m,
-      %r{<style.*?</style>}m
+      /<style.*?<\/style>/m
     )
     STRIP_HTML_TAGS = /<.*?>/m
 
@@ -74,23 +72,23 @@ module Liquid
     end
 
     # Truncate a string down to x characters
-    def truncate(input, length = 50, truncate_string = "...")
+    def truncate(input, length = 50, truncate_string = "...".freeze)
       return if input.nil?
       input_str = input.to_s
       length = Utils.to_integer(length)
       truncate_string_str = truncate_string.to_s
       l = length - truncate_string_str.length
       l = 0 if l < 0
-      input_str.length > length ? input_str[0...l].concat(truncate_string_str) : input_str
+      input_str.length > length ? input_str[0...l] + truncate_string_str : input_str
     end
 
-    def truncatewords(input, words = 15, truncate_string = "...")
+    def truncatewords(input, words = 15, truncate_string = "...".freeze)
       return if input.nil?
       wordlist = input.to_s.split
       words = Utils.to_integer(words)
       l = words - 1
       l = 0 if l < 0
-      wordlist.length > l ? wordlist[0..l].join(" ").concat(truncate_string.to_s) : input
+      wordlist.length > l ? wordlist[0..l].join(" ".freeze) + truncate_string.to_s : input
     end
 
     # Split input string into an array of substrings separated by given pattern.
@@ -115,7 +113,7 @@ module Liquid
     end
 
     def strip_html(input)
-      empty = ''
+      empty = ''.freeze
       result = input.to_s.gsub(STRIP_HTML_BLOCKS, empty)
       result.gsub!(STRIP_HTML_TAGS, empty)
       result
@@ -123,11 +121,11 @@ module Liquid
 
     # Remove all newlines from the string
     def strip_newlines(input)
-      input.to_s.gsub(/\r?\n/, '')
+      input.to_s.gsub(/\r?\n/, ''.freeze)
     end
 
     # Join elements of the array with certain character between them
-    def join(input, glue = ' ')
+    def join(input, glue = ' '.freeze)
       InputIterator.new(input).join(glue)
     end
 
@@ -222,7 +220,7 @@ module Liquid
       InputIterator.new(input).map do |e|
         e = e.call if e.is_a?(Proc)
 
-        if property == "to_liquid"
+        if property == "to_liquid".freeze
           e
         elsif e.respond_to?(:[])
           r = e[property]
@@ -252,23 +250,23 @@ module Liquid
     end
 
     # Replace occurrences of a string with another
-    def replace(input, string, replacement = '')
+    def replace(input, string, replacement = ''.freeze)
       input.to_s.gsub(string.to_s, replacement.to_s)
     end
 
     # Replace the first occurrences of a string with another
-    def replace_first(input, string, replacement = '')
+    def replace_first(input, string, replacement = ''.freeze)
       input.to_s.sub(string.to_s, replacement.to_s)
     end
 
     # remove a substring
     def remove(input, string)
-      input.to_s.gsub(string.to_s, '')
+      input.to_s.gsub(string.to_s, ''.freeze)
     end
 
     # remove the first occurrences of a substring
     def remove_first(input, string)
-      input.to_s.sub(string.to_s, '')
+      input.to_s.sub(string.to_s, ''.freeze)
     end
 
     # add one string to another
@@ -278,7 +276,7 @@ module Liquid
 
     def concat(input, array)
       unless array.respond_to?(:to_ary)
-        raise ArgumentError, "concat filter requires an array argument"
+        raise ArgumentError.new("concat filter requires an array argument")
       end
       InputIterator.new(input).concat(array)
     end
@@ -290,7 +288,7 @@ module Liquid
 
     # Add <br /> tags in front of all newlines in input string
     def newline_to_br(input)
-      input.to_s.gsub(/\n/, "<br />\n")
+      input.to_s.gsub(/\n/, "<br />\n".freeze)
     end
 
     # Reformat a date using Ruby's core Time#strftime( string ) -> string
@@ -327,7 +325,7 @@ module Liquid
     def date(input, format)
       return input if format.to_s.empty?
 
-      return input unless (date = Utils.to_date(input))
+      return input unless date = Utils.to_date(input)
 
       date.strftime(format.to_s)
     end
@@ -421,7 +419,7 @@ module Liquid
       result.is_a?(BigDecimal) ? result.to_f : result
     end
 
-    def default(input, default_value = '')
+    def default(input, default_value = ''.freeze)
       if !input || input.respond_to?(:empty?) && input.empty?
         default_value
       else
@@ -432,7 +430,7 @@ module Liquid
     private
 
     def raise_property_error(property)
-      raise Liquid::ArgumentError, "cannot select the property '#{property}'"
+      raise Liquid::ArgumentError.new("cannot select the property '#{property}'")
     end
 
     def apply_operation(input, operand, operation)

lib/liquid/static_registers.rb

@@ -1,36 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  class StaticRegisters
-    attr_reader :static, :registers
-
-    def initialize(registers = {})
-      @static = registers.is_a?(StaticRegisters) ? registers.static : registers
-      @registers = {}
-    end
-
-    def []=(key, value)
-      @registers[key] = value
-    end
-
-    def [](key)
-      if @registers.key?(key)
-        @registers[key]
-      else
-        @static[key]
-      end
-    end
-
-    def delete(key)
-      @registers.delete(key)
-    end
-
-    def fetch(key, default = nil)
-      key?(key) ? self[key] : default
-    end
-
-    def key?(key)
-      @registers.key?(key) || @static.key?(key)
-    end
-  end
-end

lib/liquid/strainer.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'set'
 
 module Liquid
@@ -29,7 +27,7 @@ module Liquid
 
     def self.add_filter(filter)
       raise ArgumentError, "Expected module but got: #{filter.class}" unless filter.is_a?(Module)
-      unless include?(filter)
+      unless self.include?(filter)
         invokable_non_public_methods = (filter.private_instance_methods + filter.protected_instance_methods).select { |m| invokable?(m) }
         if invokable_non_public_methods.any?
           raise MethodOverrideError, "Filter overrides registered public methods as non public: #{invokable_non_public_methods.join(', ')}"
@@ -56,7 +54,7 @@ module Liquid
     def invoke(method, *args)
       if self.class.invokable?(method)
         send(method, *args)
-      elsif @context&.strict_filters
+      elsif @context && @context.strict_filters
         raise Liquid::UndefinedFilter, "undefined filter #{method}"
       else
         args.first

lib/liquid/tablerowloop_drop.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   class TablerowloopDrop < Drop
     def initialize(length, cols)

lib/liquid/tag.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   class Tag
     attr_reader :nodelist, :tag_name, :line_number, :parse_context
@@ -7,8 +5,8 @@ module Liquid
     include ParserSwitching
 
     class << self
-      def parse(tag_name, markup, tokenizer, parse_context)
-        tag = new(tag_name, markup, parse_context)
+      def parse(tag_name, markup, tokenizer, options)
+        tag = new(tag_name, markup, options)
         tag.parse(tokenizer)
         tag
       end
@@ -35,15 +33,7 @@ module Liquid
     end
 
     def render(_context)
-      ''
-    end
-
-    # For backwards compatibility with custom tags. In a future release, the semantics
-    # of the `render_to_output_buffer` method will become the default and the `render`
-    # method will be removed.
-    def render_to_output_buffer(context, output)
-      output << render(context)
-      output
+      ''.freeze
     end
 
     def blank?

lib/liquid/tags/assign.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   # Assign sets a variable in your template.
   #
@@ -12,27 +10,23 @@ module Liquid
   class Assign < Tag
     Syntax = /(#{VariableSignature}+)\s*=\s*(.*)\s*/om
 
-    def self.syntax_error_translation_key
-      "errors.syntax.assign"
-    end
-
     attr_reader :to, :from
 
     def initialize(tag_name, markup, options)
       super
       if markup =~ Syntax
-        @to = Regexp.last_match(1)
-        @from = Variable.new(Regexp.last_match(2), options)
+        @to = $1
+        @from = Variable.new($2, options)
       else
-        raise SyntaxError, options[:locale].t(self.class.syntax_error_translation_key)
+        raise SyntaxError.new options[:locale].t("errors.syntax.assign".freeze)
       end
     end
 
-    def render_to_output_buffer(context, output)
+    def render(context)
       val = @from.render(context)
-      context.scopes.last[@to] = val
+      context.set_root(@to, val)
       context.resource_limits.assign_score += assign_score_of(val)
-      output
+      ''.freeze
     end
 
     def blank?
@@ -61,5 +55,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('assign', Assign)
+  Template.register_tag('assign'.freeze, Assign)
 end

lib/liquid/tags/break.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   # Break tag to be used to break out of a for loop.
   #
@@ -16,5 +14,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('break', Break)
+  Template.register_tag('break'.freeze, Break)
 end

lib/liquid/tags/capture.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   # Capture stores the result of a block into a variable without rendering it inplace.
   #
@@ -18,18 +16,17 @@ module Liquid
     def initialize(tag_name, markup, options)
       super
       if markup =~ Syntax
-        @to = Regexp.last_match(1)
+        @to = $1
       else
-        raise SyntaxError, options[:locale].t("errors.syntax.capture")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.capture"))
       end
     end
 
-    def render_to_output_buffer(context, output)
-      previous_output_size = output.bytesize
-      super
-      context.scopes.last[@to] = output
-      context.resource_limits.assign_score += (output.bytesize - previous_output_size)
-      output
+    def render(context)
+      output = super
+      context.set_root(@to, output)
+      context.resource_limits.assign_score += output.bytesize
+      ''.freeze
     end
 
     def blank?
@@ -37,5 +34,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('capture', Capture)
+  Template.register_tag('capture'.freeze, Capture)
 end

lib/liquid/tags/case.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   class Case < Block
     Syntax     = /(#{QuotedFragment})/o
@@ -12,15 +10,17 @@ module Liquid
       @blocks = []
 
       if markup =~ Syntax
-        @left = Expression.parse(Regexp.last_match(1))
+        @left = Expression.parse($1)
       else
-        raise SyntaxError, options[:locale].t("errors.syntax.case")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.case".freeze))
       end
     end
 
     def parse(tokens)
       body = BlockBody.new
-      body = @blocks.last.attachment while parse_body(body, tokens)
+      while parse_body(body, tokens)
+        body = @blocks.last.attachment
+      end
     end
 
     def nodelist
@@ -29,24 +29,25 @@ module Liquid
 
     def unknown_tag(tag, markup, tokens)
       case tag
-      when 'when'
+      when 'when'.freeze
         record_when_condition(markup)
-      when 'else'
+      when 'else'.freeze
         record_else_condition(markup)
       else
         super
       end
     end
 
-    def render_to_output_buffer(context, output)
+    def render(context)
       execute_else_block = true
 
+      output = ''
       @blocks.each do |block|
         if block.else?
-          block.attachment.render_to_output_buffer(context, output) if execute_else_block
+          return block.attachment.render(context) if execute_else_block
         elsif block.evaluate(context)
           execute_else_block = false
-          block.attachment.render_to_output_buffer(context, output)
+          output << block.attachment.render(context)
         end
       end
 
@@ -60,12 +61,12 @@ module Liquid
 
       while markup
         unless markup =~ WhenSyntax
-          raise SyntaxError, options[:locale].t("errors.syntax.case_invalid_when")
+          raise SyntaxError.new(options[:locale].t("errors.syntax.case_invalid_when".freeze))
         end
 
-        markup = Regexp.last_match(2)
+        markup = $2
 
-        block = Condition.new(@left, '==', Expression.parse(Regexp.last_match(1)))
+        block = Condition.new(@left, '=='.freeze, Expression.parse($1))
         block.attach(body)
         @blocks << block
       end
@@ -73,7 +74,7 @@ module Liquid
 
     def record_else_condition(markup)
       unless markup.strip.empty?
-        raise SyntaxError, options[:locale].t("errors.syntax.case_invalid_else")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.case_invalid_else".freeze))
       end
 
       block = ElseCondition.new
@@ -88,5 +89,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('case', Case)
+  Template.register_tag('case'.freeze, Case)
 end

lib/liquid/tags/comment.rb

@@ -1,9 +1,7 @@
-# frozen_string_literal: true
-
 module Liquid
   class Comment < Block
-    def render_to_output_buffer(_context, output)
-      output
+    def render(_context)
+      ''.freeze
     end
 
     def unknown_tag(_tag, _markup, _tokens)
@@ -14,5 +12,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('comment', Comment)
+  Template.register_tag('comment'.freeze, Comment)
 end

lib/liquid/tags/continue.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   # Continue tag to be used to break out of a for loop.
   #
@@ -16,5 +14,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('continue', Continue)
+  Template.register_tag('continue'.freeze, Continue)
 end

lib/liquid/tags/cycle.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   # Cycle is usually used within a loop to alternate between values, like colors or DOM classes.
   #
@@ -23,37 +21,26 @@ module Liquid
       super
       case markup
       when NamedSyntax
-        @variables = variables_from_string(Regexp.last_match(2))
-        @name = Expression.parse(Regexp.last_match(1))
+        @variables = variables_from_string($2)
+        @name = Expression.parse($1)
       when SimpleSyntax
         @variables = variables_from_string(markup)
         @name = @variables.to_s
       else
-        raise SyntaxError, options[:locale].t("errors.syntax.cycle")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.cycle".freeze))
       end
     end
 
-    def render_to_output_buffer(context, output)
+    def render(context)
       context.registers[:cycle] ||= {}
 
       key = context.evaluate(@name)
       iteration = context.registers[:cycle][key].to_i
-
-      val = context.evaluate(@variables[iteration])
-
-      if val.is_a?(Array)
-        val = val.join
-      elsif !val.is_a?(String)
-        val = val.to_s
-      end
-
-      output << val
-
+      result = context.evaluate(@variables[iteration])
       iteration += 1
       iteration  = 0 if iteration >= @variables.size
       context.registers[:cycle][key] = iteration
-
-      output
+      result
     end
 
     private
@@ -61,7 +48,7 @@ module Liquid
     def variables_from_string(markup)
       markup.split(',').collect do |var|
         var =~ /\s*(#{QuotedFragment})\s*/o
-        Regexp.last_match(1) ? Expression.parse(Regexp.last_match(1)) : nil
+        $1 ? Expression.parse($1) : nil
       end.compact
     end
 

lib/liquid/tags/decrement.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   # decrement is used in a place where one needs to insert a counter
   #     into a template, and needs the counter to survive across
@@ -25,14 +23,13 @@ module Liquid
       @variable = markup.strip
     end
 
-    def render_to_output_buffer(context, output)
+    def render(context)
       value = context.environments.first[@variable] ||= 0
       value -= 1
       context.environments.first[@variable] = value
-      output << value.to_s
-      output
+      value.to_s
     end
   end
 
-  Template.register_tag('decrement', Decrement)
+  Template.register_tag('decrement'.freeze, Decrement)
 end

lib/liquid/tags/echo.rb

@@ -1,26 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  # Echo outputs an expression
-  #
-  #   {% echo monkey %}
-  #   {% echo user.name %}
-  #
-  # This is identical to variable output syntax, like {{ foo }}, but works
-  # inside {% liquid %} tags. The full syntax is supported, including filters:
-  #
-  #   {% echo user | link %}
-  #
-  class Echo < Tag
-    def initialize(tag_name, markup, parse_context)
-      super
-      @variable = Variable.new(markup, parse_context)
-    end
-
-    def render(context)
-      @variable.render_to_output_buffer(context, +'')
-    end
-  end
-
-  Template.register_tag('echo', Echo)
-end

lib/liquid/tags/for.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   # "For" iterates over an array or collection.
   # Several useful variables are available to you within the loop.
@@ -68,51 +66,49 @@ module Liquid
     end
 
     def unknown_tag(tag, markup, tokens)
-      return super unless tag == 'else'
+      return super unless tag == 'else'.freeze
       @else_block = BlockBody.new
     end
 
-    def render_to_output_buffer(context, output)
+    def render(context)
       segment = collection_segment(context)
 
       if segment.empty?
-        render_else(context, output)
+        render_else(context)
       else
-        render_segment(context, output, segment)
+        render_segment(context, segment)
       end
-
-      output
     end
 
     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)
+        @variable_name = $1
+        collection_name = $2
+        @reversed = !!$3
         @name = "#{@variable_name}-#{collection_name}"
         @collection_name = Expression.parse(collection_name)
         markup.scan(TagAttributes) do |key, value|
           set_attribute(key, value)
         end
       else
-        raise SyntaxError, options[:locale].t("errors.syntax.for")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.for".freeze))
       end
     end
 
     def strict_parse(markup)
       p = Parser.new(markup)
       @variable_name = p.consume(:id)
-      raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_in") unless p.id?('in')
+      raise SyntaxError.new(options[:locale].t("errors.syntax.for_invalid_in".freeze)) unless p.id?('in'.freeze)
       collection_name = p.expression
       @name = "#{@variable_name}-#{collection_name}"
       @collection_name = Expression.parse(collection_name)
-      @reversed = p.id?('reversed')
+      @reversed = p.id?('reversed'.freeze)
 
       while p.look(:id) && p.look(:colon, 1)
-        unless (attribute = p.id?('limit') || p.id?('offset'))
-          raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_attribute")
+        unless attribute = p.id?('limit'.freeze) || p.id?('offset'.freeze)
+          raise SyntaxError.new(options[:locale].t("errors.syntax.for_invalid_attribute".freeze))
         end
         p.consume
         set_attribute(attribute, p.expression)
@@ -154,56 +150,58 @@ module Liquid
       segment
     end
 
-    def render_segment(context, output, segment)
+    def render_segment(context, segment)
       for_stack = context.registers[:for_stack] ||= []
       length = segment.length
 
-      context.stack do
+      result = ''
+
+      context.stack('forloop', @variable_name) do
         loop_vars = Liquid::ForloopDrop.new(@name, length, for_stack[-1])
 
         for_stack.push(loop_vars)
 
         begin
-          context['forloop'] = loop_vars
+          context['forloop'.freeze] = loop_vars
+          level = context.create_level(@variable_name)
 
           segment.each do |item|
-            context[@variable_name] = item
-            @for_block.render_to_output_buffer(context, output)
+            context.set_level(@variable_name, item, level)
+            result << @for_block.render(context)
             loop_vars.send(:increment!)
-
             # Handle any interrupts if they exist.
-            next unless context.interrupt?
-            interrupt = context.pop_interrupt
-            break if interrupt.is_a?(BreakInterrupt)
-            next if interrupt.is_a?(ContinueInterrupt)
+            if context.interrupt?
+              interrupt = context.pop_interrupt
+              break if interrupt.is_a? BreakInterrupt
+              next if interrupt.is_a? ContinueInterrupt
+            end
           end
+          context.unset(@variable_name)
+          context.unset('forloop'.freeze)
         ensure
+
           for_stack.pop
         end
       end
 
-      output
+      result
     end
 
     def set_attribute(key, expr)
       case key
-      when 'offset'
-        @from = if expr == 'continue'
+      when 'offset'.freeze
+        @from = if expr == 'continue'.freeze
           :continue
         else
           Expression.parse(expr)
         end
-      when 'limit'
+      when 'limit'.freeze
         @limit = Expression.parse(expr)
       end
     end
 
-    def render_else(context, output)
-      if @else_block
-        @else_block.render_to_output_buffer(context, output)
-      else
-        output
-      end
+    def render_else(context)
+      @else_block ? @else_block.render(context) : ''.freeze
     end
 
     class ParseTreeVisitor < Liquid::ParseTreeVisitor
@@ -213,5 +211,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('for', For)
+  Template.register_tag('for'.freeze, For)
 end

lib/liquid/tags/if.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   # If is the conditional block
   #
@@ -21,7 +19,7 @@ module Liquid
     def initialize(tag_name, markup, options)
       super
       @blocks = []
-      push_block('if', markup)
+      push_block('if'.freeze, markup)
     end
 
     def nodelist
@@ -34,27 +32,26 @@ module Liquid
     end
 
     def unknown_tag(tag, markup, tokens)
-      if ['elsif', 'else'].include?(tag)
+      if ['elsif'.freeze, 'else'.freeze].include?(tag)
         push_block(tag, markup)
       else
         super
       end
     end
 
-    def render_to_output_buffer(context, output)
+    def render(context)
       @blocks.each do |block|
         if block.evaluate(context)
-          return block.attachment.render_to_output_buffer(context, output)
+          return block.attachment.render(context)
         end
       end
-
-      output
+      ''.freeze
     end
 
     private
 
     def push_block(tag, markup)
-      block = if tag == 'else'
+      block = if tag == 'else'.freeze
         ElseCondition.new
       else
         parse_with_selected_parser(markup)
@@ -66,17 +63,17 @@ module Liquid
 
     def lax_parse(markup)
       expressions = markup.scan(ExpressionsAndOperators)
-      raise SyntaxError, options[:locale].t("errors.syntax.if") unless expressions.pop =~ Syntax
+      raise(SyntaxError.new(options[:locale].t("errors.syntax.if".freeze))) unless expressions.pop =~ Syntax
 
-      condition = Condition.new(Expression.parse(Regexp.last_match(1)), Regexp.last_match(2), Expression.parse(Regexp.last_match(3)))
+      condition = Condition.new(Expression.parse($1), $2, Expression.parse($3))
 
       until expressions.empty?
         operator = expressions.pop.to_s.strip
 
-        raise SyntaxError, options[:locale].t("errors.syntax.if") unless expressions.pop.to_s =~ Syntax
+        raise(SyntaxError.new(options[:locale].t("errors.syntax.if".freeze))) unless expressions.pop.to_s =~ Syntax
 
-        new_condition = Condition.new(Expression.parse(Regexp.last_match(1)), Regexp.last_match(2), Expression.parse(Regexp.last_match(3)))
-        raise SyntaxError, options[:locale].t("errors.syntax.if") unless BOOLEAN_OPERATORS.include?(operator)
+        new_condition = Condition.new(Expression.parse($1), $2, Expression.parse($3))
+        raise(SyntaxError.new(options[:locale].t("errors.syntax.if".freeze))) unless BOOLEAN_OPERATORS.include?(operator)
         new_condition.send(operator, condition)
         condition = new_condition
       end
@@ -94,7 +91,7 @@ module Liquid
     def parse_binary_comparisons(p)
       condition = parse_comparison(p)
       first_condition = condition
-      while (op = (p.id?('and') || p.id?('or')))
+      while op = (p.id?('and'.freeze) || p.id?('or'.freeze))
         child_condition = parse_comparison(p)
         condition.send(op, child_condition)
         condition = child_condition
@@ -104,7 +101,7 @@ module Liquid
 
     def parse_comparison(p)
       a = Expression.parse(p.expression)
-      if (op = p.consume?(:comparison))
+      if op = p.consume?(:comparison)
         b = Expression.parse(p.expression)
         Condition.new(a, op, b)
       else
@@ -119,5 +116,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('if', If)
+  Template.register_tag('if'.freeze, If)
 end

lib/liquid/tags/ifchanged.rb

@@ -1,19 +1,16 @@
-# frozen_string_literal: true
-
 module Liquid
   class Ifchanged < Block
-    def render_to_output_buffer(context, output)
-      block_output = +''
-      super(context, block_output)
+    def render(context)
+      output = super
 
-      if block_output != context.registers[:ifchanged]
-        context.registers[:ifchanged] = block_output
-        output << block_output
+      if output != context.registers[:ifchanged]
+        context.registers[:ifchanged] = output
+        output
+      else
+        ''.freeze
       end
-
-      output
     end
   end
 
-  Template.register_tag('ifchanged', Ifchanged)
+  Template.register_tag('ifchanged'.freeze, Ifchanged)
 end

lib/liquid/tags/include.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   # Include allows templates to relate with other templates
   #
@@ -25,8 +23,8 @@ module Liquid
 
       if markup =~ Syntax
 
-        template_name = Regexp.last_match(1)
-        variable_name = Regexp.last_match(3)
+        template_name = $1
+        variable_name = $3
 
         @variable_name_expr = variable_name ? Expression.parse(variable_name) : nil
         @template_name_expr = Expression.parse(template_name)
@@ -37,24 +35,19 @@ module Liquid
         end
 
       else
-        raise SyntaxError, options[:locale].t("errors.syntax.include")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.include".freeze))
       end
     end
 
     def parse(_tokens)
     end
 
-    def render_to_output_buffer(context, output)
+    def render(context)
       template_name = context.evaluate(@template_name_expr)
-      raise ArgumentError, options[:locale].t("errors.argument.include") unless template_name
+      raise ArgumentError.new(options[:locale].t("errors.argument.include")) unless template_name
 
-      partial = PartialCache.load(
-        template_name,
-        context: context,
-        parse_context: parse_context
-      )
-
-      context_variable_name = template_name.split('/').last
+      partial = load_cached_partial(template_name, context)
+      context_variable_name = template_name.split('/'.freeze).last
 
       variable = if @variable_name_expr
         context.evaluate(@variable_name_expr)
@@ -67,41 +60,65 @@ module Liquid
       begin
         context.template_name = template_name
         context.partial = true
-        context.stack do
+        context.stack(context_variable_name, *@attributes.keys) do
           @attributes.each do |key, value|
             context[key] = context.evaluate(value)
           end
 
           if variable.is_a?(Array)
-            variable.each do |var|
+            variable.collect do |var|
               context[context_variable_name] = var
-              partial.render_to_output_buffer(context, output)
+              partial.render(context)
             end
           else
             context[context_variable_name] = variable
-            partial.render_to_output_buffer(context, output)
+            partial.render(context)
           end
         end
       ensure
         context.template_name = old_template_name
         context.partial = old_partial
       end
-
-      output
     end
 
+    private
+
     alias_method :parse_context, :options
     private :parse_context
 
+    def load_cached_partial(template_name, context)
+      cached_partials = context.registers[:cached_partials] || {}
+
+      if cached = cached_partials[template_name]
+        return cached
+      end
+      source = read_template_from_file_system(context)
+      begin
+        parse_context.partial = true
+        partial = Liquid::Template.parse(source, parse_context)
+      ensure
+        parse_context.partial = false
+      end
+      cached_partials[template_name] = partial
+      context.registers[:cached_partials] = cached_partials
+      partial
+    end
+
+    def read_template_from_file_system(context)
+      file_system = context.registers[:file_system] || Liquid::Template.file_system
+
+      file_system.read_template_file(context.evaluate(@template_name_expr))
+    end
+
     class ParseTreeVisitor < Liquid::ParseTreeVisitor
       def children
         [
           @node.template_name_expr,
-          @node.variable_name_expr,
+          @node.variable_name_expr
         ] + @node.attributes.values
       end
     end
   end
 
-  Template.register_tag('include', Include)
+  Template.register_tag('include'.freeze, Include)
 end

lib/liquid/tags/increment.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   # increment is used in a place where one needs to insert a counter
   #     into a template, and needs the counter to survive across
@@ -22,14 +20,12 @@ module Liquid
       @variable = markup.strip
     end
 
-    def render_to_output_buffer(context, output)
+    def render(context)
       value = context.environments.first[@variable] ||= 0
       context.environments.first[@variable] = value + 1
-
-      output << value.to_s
-      output
+      value.to_s
     end
   end
 
-  Template.register_tag('increment', Increment)
+  Template.register_tag('increment'.freeze, Increment)
 end

lib/liquid/tags/raw.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   class Raw < Block
     Syntax = /\A\s*\z/
@@ -12,21 +10,20 @@ module Liquid
     end
 
     def parse(tokens)
-      @body = +''
-      while (token = tokens.shift)
+      @body = ''
+      while token = tokens.shift
         if token =~ FullTokenPossiblyInvalid
-          @body << Regexp.last_match(1) if Regexp.last_match(1) != ""
-          return if block_delimiter == Regexp.last_match(2)
+          @body << $1 if $1 != "".freeze
+          return if block_delimiter == $2
         end
         @body << token unless token.empty?
       end
 
-      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed", block_name: block_name)
+      raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_never_closed".freeze, block_name: block_name))
     end
 
-    def render_to_output_buffer(_context, output)
-      output << @body
-      output
+    def render(_context)
+      @body
     end
 
     def nodelist
@@ -40,11 +37,11 @@ module Liquid
     protected
 
     def ensure_valid_markup(tag_name, markup, parse_context)
-      unless Syntax.match?(markup)
-        raise SyntaxError, parse_context.locale.t("errors.syntax.tag_unexpected_args", tag: tag_name)
+      unless markup =~ Syntax
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_unexpected_args".freeze, tag: tag_name))
       end
     end
   end
 
-  Template.register_tag('raw', Raw)
+  Template.register_tag('raw'.freeze, Raw)
 end

lib/liquid/tags/render.rb

@@ -1,56 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  class Render < Tag
-    SYNTAX = /(#{QuotedString})#{QuotedFragment}*/o
-
-    attr_reader :template_name_expr, :attributes
-
-    def initialize(tag_name, markup, options)
-      super
-
-      raise SyntaxError, options[:locale].t("errors.syntax.render") unless markup =~ SYNTAX
-
-      template_name = Regexp.last_match(1)
-
-      @template_name_expr = Expression.parse(template_name)
-
-      @attributes = {}
-      markup.scan(TagAttributes) do |key, value|
-        @attributes[key] = Expression.parse(value)
-      end
-    end
-
-    def render_to_output_buffer(context, output)
-      # Though we evaluate this here we will only ever parse it as a string literal.
-      template_name = context.evaluate(@template_name_expr)
-      raise ArgumentError, options[:locale].t("errors.argument.include") unless template_name
-
-      partial = PartialCache.load(
-        template_name,
-        context: context,
-        parse_context: parse_context
-      )
-
-      inner_context = context.new_isolated_subcontext
-      inner_context.template_name = template_name
-      inner_context.partial = true
-      @attributes.each do |key, value|
-        inner_context[key] = context.evaluate(value)
-      end
-      partial.render_to_output_buffer(inner_context, output)
-
-      output
-    end
-
-    class ParseTreeVisitor < Liquid::ParseTreeVisitor
-      def children
-        [
-          @node.template_name_expr,
-        ] + @node.attributes.values
-      end
-    end
-  end
-
-  Template.register_tag('render', Render)
-end

lib/liquid/tags/table_row.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   class TableRow < Block
     Syntax = /(\w+)\s+in\s+(#{QuotedFragment}+)/o
@@ -9,51 +7,48 @@ module Liquid
     def initialize(tag_name, markup, options)
       super
       if markup =~ Syntax
-        @variable_name = Regexp.last_match(1)
-        @collection_name = Expression.parse(Regexp.last_match(2))
+        @variable_name = $1
+        @collection_name = Expression.parse($2)
         @attributes = {}
         markup.scan(TagAttributes) do |key, value|
           @attributes[key] = Expression.parse(value)
         end
       else
-        raise SyntaxError, options[:locale].t("errors.syntax.table_row")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.table_row".freeze))
       end
     end
 
-    def render_to_output_buffer(context, output)
-      (collection = context.evaluate(@collection_name)) || (return '')
+    def render(context)
+      collection = context.evaluate(@collection_name) or return ''.freeze
 
-      from = @attributes.key?('offset') ? context.evaluate(@attributes['offset']).to_i : 0
-      to = @attributes.key?('limit') ? from + context.evaluate(@attributes['limit']).to_i : nil
+      from = @attributes.key?('offset'.freeze) ? context.evaluate(@attributes['offset'.freeze]).to_i : 0
+      to = @attributes.key?('limit'.freeze) ? from + context.evaluate(@attributes['limit'.freeze]).to_i : nil
 
       collection = Utils.slice_collection(collection, from, to)
 
       length = collection.length
 
-      cols = context.evaluate(@attributes['cols']).to_i
+      cols = context.evaluate(@attributes['cols'.freeze]).to_i
 
-      output << "<tr class=\"row1\">\n"
-      context.stack do
+      result = "<tr class=\"row1\">\n"
+      context.stack('tablerowloop', @variable_name) do
         tablerowloop = Liquid::TablerowloopDrop.new(length, cols)
-        context['tablerowloop'] = tablerowloop
+        context['tablerowloop'.freeze] = tablerowloop
 
         collection.each do |item|
           context[@variable_name] = item
 
-          output << "<td class=\"col#{tablerowloop.col}\">"
-          super
-          output << '</td>'
+          result << "<td class=\"col#{tablerowloop.col}\">" << super << '</td>'
 
           if tablerowloop.col_last && !tablerowloop.last
-            output << "</tr>\n<tr class=\"row#{tablerowloop.row + 1}\">"
+            result << "</tr>\n<tr class=\"row#{tablerowloop.row + 1}\">"
           end
 
           tablerowloop.send(:increment!)
         end
       end
-
-      output << "</tr>\n"
-      output
+      result << "</tr>\n"
+      result
     end
 
     class ParseTreeVisitor < Liquid::ParseTreeVisitor
@@ -63,5 +58,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('tablerow', TableRow)
+  Template.register_tag('tablerow'.freeze, TableRow)
 end

lib/liquid/tags/unless.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require_relative 'if'
 
 module Liquid
@@ -8,23 +6,23 @@ module Liquid
   #   {% unless x < 0 %} x is greater than zero {% endunless %}
   #
   class Unless < If
-    def render_to_output_buffer(context, output)
+    def render(context)
       # First condition is interpreted backwards ( if not )
       first_block = @blocks.first
       unless first_block.evaluate(context)
-        return first_block.attachment.render_to_output_buffer(context, output)
+        return first_block.attachment.render(context)
       end
 
       # After the first condition unless works just like if
       @blocks[1..-1].each do |block|
         if block.evaluate(context)
-          return block.attachment.render_to_output_buffer(context, output)
+          return block.attachment.render(context)
         end
       end
 
-      output
+      ''.freeze
     end
   end
 
-  Template.register_tag('unless', Unless)
+  Template.register_tag('unless'.freeze, Unless)
 end

lib/liquid/template.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   # Templates are central to liquid.
   # Interpretating templates is a two step process. First you compile the
@@ -52,7 +50,7 @@ module Liquid
       private
 
       def lookup_class(name)
-        Object.const_get(name)
+        name.split("::").reject(&:empty?).reduce(Object) { |scope, const| scope.const_get(const) }
       end
     end
 
@@ -167,14 +165,14 @@ module Liquid
     #    filters and tags and might be useful to integrate liquid more with its host application
     #
     def render(*args)
-      return '' if @root.nil?
+      return ''.freeze if @root.nil?
 
       context = case args.first
       when Liquid::Context
         c = args.shift
 
         if @rethrow_errors
-          c.exception_renderer = ->(_e) { raise }
+          c.exception_renderer = ->(e) { raise }
         end
 
         c
@@ -189,12 +187,9 @@ module Liquid
         raise ArgumentError, "Expected Hash or Liquid::Context as parameter"
       end
 
-      output = nil
-
       case args.last
       when Hash
         options = args.pop
-        output = options[:output] if options[:output]
 
         registers.merge!(options[:registers]) if options[:registers].is_a?(Hash)
 
@@ -209,9 +204,10 @@ module Liquid
       begin
         # render the nodelist.
         # for performance reasons we get an array back here. join will make a string out of it.
-        with_profiling(context) do
-          @root.render_to_output_buffer(context, output || +'')
+        result = with_profiling(context) do
+          @root.render(context)
         end
+        result.respond_to?(:join) ? result.join : result
       rescue Liquid::MemoryError => e
         context.handle_error(e)
       ensure
@@ -224,10 +220,6 @@ module Liquid
       render(*args)
     end
 
-    def render_to_output_buffer(context, output)
-      render(context, output: output)
-    end
-
     private
 
     def tokenize(source)

lib/liquid/tokenizer.rb

@@ -1,37 +1,29 @@
-# frozen_string_literal: true
-
 module Liquid
   class Tokenizer
-    attr_reader :line_number, :for_liquid_tag
+    attr_reader :line_number
 
-    def initialize(source, line_numbers = false, line_number: nil, for_liquid_tag: false)
+    def initialize(source, line_numbers = false)
       @source = source
-      @line_number = line_number || (line_numbers ? 1 : nil)
-      @for_liquid_tag = for_liquid_tag
+      @line_number = line_numbers ? 1 : nil
       @tokens = tokenize
     end
 
     def shift
-      (token = @tokens.shift) || return
-
-      if @line_number
-        @line_number += @for_liquid_tag ? 1 : token.count("\n")
-      end
-
+      token = @tokens.shift
+      @line_number += token.count("\n") if @line_number && token
       token
     end
 
     private
 
     def tokenize
+      @source = @source.source if @source.respond_to?(:source)
       return [] if @source.to_s.empty?
 
-      return @source.split("\n") if @for_liquid_tag
-
       tokens = @source.split(TemplateParser)
 
       # removes the rogue empty element at the beginning of the array
-      tokens.shift if tokens[0]&.empty?
+      tokens.shift if tokens[0] && tokens[0].empty?
 
       tokens
     end

lib/liquid/usage.rb

@@ -1,8 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  module Usage
-    def self.increment(name)
-    end
-  end
-end

lib/liquid/utils.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   module Utils
     def self.slice_collection(collection, from, to)
@@ -52,7 +50,7 @@ module Liquid
       when Numeric
         obj
       when String
-        /\A-?\d+\.\d+\z/.match?(obj.strip) ? BigDecimal(obj) : obj.to_i
+        (obj.strip =~ /\A-?\d+\.\d+\z/) ? BigDecimal(obj) : obj.to_i
       else
         if obj.respond_to?(:to_number)
           obj.to_number
@@ -71,7 +69,7 @@ module Liquid
       end
 
       case obj
-      when 'now', 'today'
+      when 'now'.freeze, 'today'.freeze
         Time.now
       when /\A\d+\z/, Integer
         Time.at(obj.to_i)

lib/liquid/variable.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
   # Holds variables. Variables are only loaded "just in time"
   # and are not evaluated as part of the render stage
@@ -45,11 +43,11 @@ module Liquid
       @filters = []
       return unless markup =~ MarkupWithQuotedFragment
 
-      name_markup = Regexp.last_match(1)
-      filter_markup = Regexp.last_match(2)
+      name_markup = $1
+      filter_markup = $2
       @name = Expression.parse(name_markup)
       if filter_markup =~ FilterMarkupRegex
-        filters = Regexp.last_match(1).scan(FilterParser)
+        filters = $1.scan(FilterParser)
         filters.each do |f|
           next unless f =~ /\w+/
           filtername = Regexp.last_match(0)
@@ -87,30 +85,19 @@ module Liquid
       end
 
       obj = context.apply_global_filter(obj)
+
       taint_check(context, obj)
+
       obj
     end
 
-    def render_to_output_buffer(context, output)
-      obj = render(context)
-
-      if obj.is_a?(Array)
-        output << obj.join
-      elsif obj.nil?
-      else
-        output << obj.to_s
-      end
-
-      output
-    end
-
     private
 
     def parse_filter_expressions(filter_name, unparsed_args)
       filter_args = []
       keyword_args = nil
       unparsed_args.each do |a|
-        if (matches = a.match(JustTagAttributes))
+        if matches = a.match(JustTagAttributes)
           keyword_args ||= {}
           keyword_args[matches[1]] = Expression.parse(matches[2])
         else
@@ -123,7 +110,7 @@ module Liquid
     end
 
     def evaluate_filter_expressions(context, filter_args, filter_kwargs)
-      parsed_args = filter_args.map { |expr| context.evaluate(expr) }
+      parsed_args = filter_args.map{ |expr| context.evaluate(expr) }
       if filter_kwargs
         parsed_kwargs = {}
         filter_kwargs.each do |key, expr|

lib/liquid/variable_lookup.rb

@@ -1,9 +1,7 @@
-# frozen_string_literal: true
-
 module Liquid
   class VariableLookup
     SQUARE_BRACKETED = /\A\[(.*)\]\z/m
-    COMMAND_METHODS = ['size', 'first', 'last'].freeze
+    COMMAND_METHODS = ['size'.freeze, 'first'.freeze, 'last'.freeze].freeze
 
     attr_reader :name, :lookups
 
@@ -16,7 +14,7 @@ module Liquid
 
       name = lookups.shift
       if name =~ SQUARE_BRACKETED
-        name = Expression.parse(Regexp.last_match(1))
+        name = Expression.parse($1)
       end
       @name = name
 
@@ -26,7 +24,7 @@ module Liquid
       @lookups.each_index do |i|
         lookup = lookups[i]
         if lookup =~ SQUARE_BRACKETED
-          lookups[i] = Expression.parse(Regexp.last_match(1))
+          lookups[i] = Expression.parse($1)
         elsif COMMAND_METHODS.include?(lookup)
           @command_flags |= 1 << i
         end

lib/liquid/version.rb

@@ -1,6 +1,5 @@
 # encoding: utf-8
-# frozen_string_literal: true
 
 module Liquid
-  VERSION = "4.0.3"
+  VERSION = "4.0.3".freeze
 end

liquid.gemspec

@@ -1,8 +1,7 @@
 # encoding: utf-8
-# frozen_string_literal: true
 
 lib = File.expand_path('../lib/', __FILE__)
-$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
+$LOAD_PATH.unshift lib unless $LOAD_PATH.include?(lib)
 
 require "liquid/version"
 
@@ -17,7 +16,7 @@ Gem::Specification.new do |s|
   s.license     = "MIT"
   # s.description = "A secure, non-evaling end user template engine with aesthetic markup."
 
-  s.required_ruby_version     = ">= 2.4.0"
+  s.required_ruby_version     = ">= 2.1.0"
   s.required_rubygems_version = ">= 1.3.7"
 
   s.test_files  = Dir.glob("{test}/**/*")
@@ -27,6 +26,6 @@ Gem::Specification.new do |s|
 
   s.require_path = "lib"
 
-  s.add_development_dependency('rake', '~> 11.3')
-  s.add_development_dependency('minitest')
+  s.add_development_dependency 'rake', '~> 11.3'
+  s.add_development_dependency 'minitest'
 end

performance/benchmark.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'benchmark/ips'
 require_relative 'theme_runner'
 

performance/memory_profile.rb

@@ -2,62 +2,25 @@
 
 require 'benchmark/ips'
 require 'memory_profiler'
-require 'terminal-table'
 require_relative 'theme_runner'
 
-class Profiler
-  LOG_LABEL   = "Profiling: ".rjust(14).freeze
-  REPORTS_DIR = File.expand_path('.memprof', __dir__).freeze
+def profile(phase, &block)
+  puts
+  puts "#{phase}:"
+  puts
 
-  def self.run
-    puts
-    yield new
-  end
+  report = MemoryProfiler.report(&block)
 
-  def initialize
-    @allocated = []
-    @retained  = []
-    @headings  = []
-  end
-
-  def profile(phase, &block)
-    print LOG_LABEL
-    print "#{phase}.. ".ljust(10)
-    report = MemoryProfiler.report(&block)
-    puts 'Done.'
-    @headings  << phase.capitalize
-    @allocated << "#{report.scale_bytes(report.total_allocated_memsize)} (#{report.total_allocated} objects)"
-    @retained  << "#{report.scale_bytes(report.total_retained_memsize)} (#{report.total_retained} objects)"
-
-    return if ENV['CI']
-
-    require 'fileutils'
-    report_file = File.join(REPORTS_DIR, "#{sanitize(phase)}.txt")
-    FileUtils.mkdir_p(REPORTS_DIR)
-    report.pretty_print(to_file: report_file, scale_bytes: true)
-  end
-
-  def tabulate
-    table = Terminal::Table.new(headings: @headings.unshift('Phase')) do |t|
-      t << @allocated.unshift('Total allocated')
-      t << @retained.unshift('Total retained')
-    end
-
-    puts
-    puts table
-    puts "\nDetailed report(s) saved to #{REPORTS_DIR}/" unless ENV['CI']
-  end
-
-  def sanitize(string)
-    string.downcase.gsub(/[\W]/, '-').squeeze('-')
-  end
+  report.pretty_print(
+    color_output: true,
+    scale_bytes: true,
+    detailed_report: true
+  )
 end
 
 Liquid::Template.error_mode = ARGV.first.to_sym if ARGV.first
 
-runner = ThemeRunner.new
-Profiler.run do |x|
-  x.profile('parse') { runner.compile }
-  x.profile('render') { runner.render }
-  x.tabulate
-end
+profiler = ThemeRunner.new
+
+profile("Parsing") { profiler.compile }
+profile("Rendering") { profiler.render }

performance/profile.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'stackprof'
 require_relative 'theme_runner'
 
@@ -15,7 +13,7 @@ profiler.run
     end
   end
 
-  if profile_type == :cpu && (graph_filename = ENV['GRAPH_FILENAME'])
+  if profile_type == :cpu && graph_filename = ENV['GRAPH_FILENAME']
     File.open(graph_filename, 'w') do |f|
       StackProf::Report.new(results).print_graphviz(nil, f)
     end

performance/shopify/comment_form.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 class CommentForm < Liquid::Block
   Syntax = /(#{Liquid::VariableSignature}+)/
 
@@ -7,27 +5,25 @@ class CommentForm < Liquid::Block
     super
 
     if markup =~ Syntax
-      @variable_name = Regexp.last_match(1)
+      @variable_name = $1
       @attributes = {}
     else
-      raise SyntaxError, "Syntax Error in 'comment_form' - Valid syntax: comment_form [article]"
+      raise SyntaxError.new("Syntax Error in 'comment_form' - Valid syntax: comment_form [article]")
     end
   end
 
-  def render_to_output_buffer(context, output)
+  def render(context)
     article = context[@variable_name]
 
-    context.stack do
+    context.stack('form') do
       context['form'] = {
         'posted_successfully?' => context.registers[:posted_successfully],
         'errors' => context['comment.errors'],
         'author' => context['comment.author'],
-        'email' => context['comment.email'],
-        'body' => context['comment.body'],
+        'email'  => context['comment.email'],
+        'body'   => context['comment.body']
       }
-
-      output << wrap_in_form(article, render_all(@nodelist, context, output))
-      output
+      wrap_in_form(article, render_all(@nodelist, context))
     end
   end
 

performance/shopify/database.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'yaml'
 
 module Database
@@ -18,10 +16,9 @@ module Database
       end
 
       # key the tables by handles, as this is how liquid expects it.
-      db = db.each_with_object({}) do |(key, values), assigns|
-        assigns[key] = values.each_with_object({}) do |v, h|
-          h[v['handle']] = v
-        end
+      db = db.inject({}) do |assigns, (key, values)|
+        assigns[key] = values.inject({}) { |h, v| h[v['handle']] = v; h; }
+        assigns
       end
 
       # Some standard direct accessors so that the specialized templates
@@ -32,9 +29,9 @@ module Database
       db['article']    = db['blog']['articles'].first
 
       db['cart']       = {
-        'total_price' => db['line_items'].values.inject(0) { |sum, item| sum + item['line_price'] * item['quantity'] },
-        'item_count' => db['line_items'].values.inject(0) { |sum, item| sum + item['quantity'] },
-        'items' => db['line_items'].values,
+        'total_price' => db['line_items'].values.inject(0) { |sum, item| sum += item['line_price'] * item['quantity'] },
+        'item_count'  => db['line_items'].values.inject(0) { |sum, item| sum += item['quantity'] },
+        'items'       => db['line_items'].values
       }
 
       db
@@ -43,6 +40,6 @@ module Database
 end
 
 if __FILE__ == $PROGRAM_NAME
-  p(Database.tables['collections']['frontpage'].keys)
+  p Database.tables['collections']['frontpage'].keys
   # p Database.tables['blog']['articles']
 end

performance/shopify/json_filter.rb

@@ -1,9 +1,7 @@
-# frozen_string_literal: true
-
 require 'json'
 
 module JsonFilter
   def json(object)
-    JSON.dump(object.reject { |k, _v| k == "collections" })
+    JSON.dump(object.reject { |k, v| k == "collections" })
   end
 end

performance/shopify/liquid.rb

@@ -1,6 +1,4 @@
-# frozen_string_literal: true
-
-$LOAD_PATH.unshift(__dir__ + '/../../lib')
+$:.unshift __dir__ + '/../../lib'
 require_relative '../../lib/liquid'
 
 require_relative 'comment_form'
@@ -11,11 +9,11 @@ require_relative 'shop_filter'
 require_relative 'tag_filter'
 require_relative 'weight_filter'
 
-Liquid::Template.register_tag('paginate', Paginate)
-Liquid::Template.register_tag('form', CommentForm)
+Liquid::Template.register_tag 'paginate', Paginate
+Liquid::Template.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)
+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

performance/shopify/money_filter.rb

@@ -1,14 +1,12 @@
-# frozen_string_literal: true
-
 module MoneyFilter
   def money_with_currency(money)
     return '' if money.nil?
-    format("$ %.2f USD", money / 100.0)
+    sprintf("$ %.2f USD", money / 100.0)
   end
 
   def money(money)
     return '' if money.nil?
-    format("$ %.2f", money / 100.0)
+    sprintf("$ %.2f", money / 100.0)
   end
 
   private

performance/shopify/paginate.rb

@@ -1,15 +1,13 @@
-# frozen_string_literal: true
-
 class Paginate < Liquid::Block
-  Syntax = /(#{Liquid::QuotedFragment})\s*(by\s*(\d+))?/
+  Syntax     = /(#{Liquid::QuotedFragment})\s*(by\s*(\d+))?/
 
   def initialize(tag_name, markup, options)
     super
 
     if markup =~ Syntax
-      @collection_name = Regexp.last_match(1)
-      @page_size = if Regexp.last_match(2)
-        Regexp.last_match(3).to_i
+      @collection_name = $1
+      @page_size = if $2
+        $3.to_i
       else
         20
       end
@@ -19,27 +17,27 @@ class Paginate < Liquid::Block
         @attributes[key] = value
       end
     else
-      raise SyntaxError, "Syntax Error in tag 'paginate' - Valid syntax: paginate [collection] by number"
+      raise SyntaxError.new("Syntax Error in tag 'paginate' - Valid syntax: paginate [collection] by number")
     end
   end
 
-  def render_to_output_buffer(context, output)
+  def render(context)
     @context = context
 
-    context.stack do
-      current_page = context['current_page'].to_i
+    context.stack('paginate') do
+      current_page  = context['current_page'].to_i
 
       pagination = {
-        'page_size' => @page_size,
-        'current_page' => 5,
-        'current_offset' => @page_size * 5,
+        'page_size'      => @page_size,
+        'current_page'   => 5,
+        'current_offset' => @page_size * 5
       }
 
       context['paginate'] = pagination
 
-      collection_size = context[@collection_name].size
+      collection_size  = context[@collection_name].size
 
-      raise ArgumentError, "Cannot paginate array '#{@collection_name}'. Not found." if collection_size.nil?
+      raise ArgumentError.new("Cannot paginate array '#{@collection_name}'. Not found.") if collection_size.nil?
 
       page_count = (collection_size.to_f / @page_size.to_f).to_f.ceil + 1
 

performance/shopify/shop_filter.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module ShopFilter
   def asset_url(input)
     "/files/1/[shop_id]/[shop_id]/assets/#{input}"
@@ -54,7 +52,7 @@ module ShopFilter
   end
 
   def product_img_url(url, style = 'small')
-    unless url =~ %r{\Aproducts/([\w\-\_]+)\.(\w{2,4})}
+    unless url =~ /\Aproducts\/([\w\-\_]+)\.(\w{2,4})/
       raise ArgumentError, 'filter "size" can only be called on product images'
     end
 
@@ -62,7 +60,7 @@ module ShopFilter
     when 'original'
       return '/files/shops/random_number/' + url
     when 'grande', 'large', 'medium', 'compact', 'small', 'thumb', 'icon'
-      "/files/shops/random_number/products/#{Regexp.last_match(1)}_#{style}.#{Regexp.last_match(2)}"
+      "/files/shops/random_number/products/#{$1}_#{style}.#{$2}"
     else
       raise ArgumentError, 'valid parameters for filter "size" are: original, grande, large, medium, compact, small, thumb and icon '
     end
@@ -72,14 +70,16 @@ module ShopFilter
     html = []
     html << %(<span class="prev">#{link_to(paginate['previous']['title'], paginate['previous']['url'])}</span>) if paginate['previous']
 
-    paginate['parts'].each do |part|
-      html << if part['is_link']
-        %(<span class="page">#{link_to(part['title'], part['url'])}</span>)
+    for part in paginate['parts']
+
+      if part['is_link']
+        html << %(<span class="page">#{link_to(part['title'], part['url'])}</span>)
       elsif part['title'].to_i == paginate['current_page'].to_i
-        %(<span class="page current">#{part['title']}</span>)
+        html << %(<span class="page current">#{part['title']}</span>)
       else
-        %(<span class="deco">#{part['title']}</span>)
+        html << %(<span class="deco">#{part['title']}</span>)
       end
+
     end
 
     html << %(<span class="next">#{link_to(paginate['next']['title'], paginate['next']['url'])}</span>) if paginate['next']

performance/shopify/tag_filter.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module TagFilter
   def link_to_tag(label, tag)
     "<a title=\"Show tag #{tag}\" href=\"/collections/#{@context['handle']}/#{tag}\">#{label}</a>"
@@ -15,11 +13,11 @@ module TagFilter
 
   def link_to_add_tag(label, tag)
     tags = (@context['current_tags'] + [tag]).uniq
-    "<a title=\"Show tag #{tag}\" href=\"/collections/#{@context['handle']}/#{tags.join('+')}\">#{label}</a>"
+    "<a title=\"Show tag #{tag}\" href=\"/collections/#{@context['handle']}/#{tags.join("+")}\">#{label}</a>"
   end
 
   def link_to_remove_tag(label, tag)
     tags = (@context['current_tags'] - [tag]).uniq
-    "<a title=\"Show tag #{tag}\" href=\"/collections/#{@context['handle']}/#{tags.join('+')}\">#{label}</a>"
+    "<a title=\"Show tag #{tag}\" href=\"/collections/#{@context['handle']}/#{tags.join("+")}\">#{label}</a>"
   end
 end

performance/shopify/weight_filter.rb

@@ -1,8 +1,6 @@
-# frozen_string_literal: true
-
 module WeightFilter
   def weight(grams)
-    format("%.2f", grams / 1000)
+    sprintf("%.2f", grams / 1000)
   end
 
   def weight_with_unit(grams)

performance/theme_runner.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 # This profiler run simulates Shopify.
 # We are looking in the tests directory for liquid files and render them within the designated layout file.
 # We will also export a substantial database to liquid which the templates can render values of.
@@ -33,7 +31,7 @@ class ThemeRunner
       {
         liquid: File.read(test),
         layout: (File.file?(theme_path) ? File.read(theme_path) : nil),
-        template_name: test,
+        template_name: test
       }
     end.compact
 

test/integration/assign_test.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 class AssignTest < Minitest::Test

test/integration/blank_test.rb

@@ -1,12 +1,11 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 class FoobarTag < Liquid::Tag
-  def render_to_output_buffer(_context, output)
-    output << ' '
-    output
+  def render(*args)
+    " "
   end
+
+  Liquid::Template.register_tag('foobar', FoobarTag)
 end
 
 class BlankTestFileSystem
@@ -32,9 +31,7 @@ class BlankTest < Minitest::Test
   end
 
   def test_new_tags_are_not_blank_by_default
-    with_custom_tag('foobar', FoobarTag) do
-      assert_template_result(" " * N, wrap_in_for("{% foobar %}"))
-    end
+    assert_template_result(" " * N, wrap_in_for("{% foobar %}"))
   end
 
   def test_loops_are_blank

test/integration/block_test.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 class BlockTest < Minitest::Test

test/integration/capture_test.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 class CaptureTest < Minitest::Test

test/integration/context_test.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 class ContextTest < Minitest::Test

test/integration/document_test.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 class DocumentTest < Minitest::Test

test/integration/drop_test.rb

@@ -1,16 +1,6 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 class ContextDrop < Liquid::Drop
-  def scopes
-    @context.scopes.size
-  end
-
-  def scopes_as_array
-    (1..@context.scopes.size).to_a
-  end
-
   def loop_pos
     @context['forloop.index']
   end
@@ -33,7 +23,7 @@ class ProductDrop < Liquid::Drop
 
   class CatchallDrop < Liquid::Drop
     def liquid_method_missing(method)
-      "catchall_method: #{method}"
+      'catchall_method: ' << method.to_s
     end
   end
 
@@ -50,7 +40,7 @@ class ProductDrop < Liquid::Drop
   end
 
   def user_input
-    (+"foo").taint
+    "foo".taint
   end
 
   protected
@@ -196,31 +186,6 @@ class DropsTest < Minitest::Test
     end
   end
 
-  def test_scope
-    assert_equal '1', Liquid::Template.parse('{{ context.scopes }}').render!('context' => ContextDrop.new)
-    assert_equal '2', Liquid::Template.parse('{%for i in dummy%}{{ context.scopes }}{%endfor%}').render!('context' => ContextDrop.new, 'dummy' => [1])
-    assert_equal '3', Liquid::Template.parse('{%for i in dummy%}{%for i in dummy%}{{ context.scopes }}{%endfor%}{%endfor%}').render!('context' => ContextDrop.new, 'dummy' => [1])
-  end
-
-  def test_scope_though_proc
-    assert_equal '1', Liquid::Template.parse('{{ s }}').render!('context' => ContextDrop.new, 's' => proc { |c| c['context.scopes'] })
-    assert_equal '2', Liquid::Template.parse('{%for i in dummy%}{{ s }}{%endfor%}').render!('context' => ContextDrop.new, 's' => proc { |c| c['context.scopes'] }, 'dummy' => [1])
-    assert_equal '3', Liquid::Template.parse('{%for i in dummy%}{%for i in dummy%}{{ s }}{%endfor%}{%endfor%}').render!('context' => ContextDrop.new, 's' => proc { |c| c['context.scopes'] }, 'dummy' => [1])
-  end
-
-  def test_scope_with_assigns
-    assert_equal 'variable', Liquid::Template.parse('{% assign a = "variable"%}{{a}}').render!('context' => ContextDrop.new)
-    assert_equal 'variable', Liquid::Template.parse('{% assign a = "variable"%}{%for i in dummy%}{{a}}{%endfor%}').render!('context' => ContextDrop.new, 'dummy' => [1])
-    assert_equal 'test', Liquid::Template.parse('{% assign header_gif = "test"%}{{header_gif}}').render!('context' => ContextDrop.new)
-    assert_equal 'test', Liquid::Template.parse("{% assign header_gif = 'test'%}{{header_gif}}").render!('context' => ContextDrop.new)
-  end
-
-  def test_scope_from_tags
-    assert_equal '1', Liquid::Template.parse('{% for i in context.scopes_as_array %}{{i}}{% endfor %}').render!('context' => ContextDrop.new, 'dummy' => [1])
-    assert_equal '12', Liquid::Template.parse('{%for a in dummy%}{% for i in context.scopes_as_array %}{{i}}{% endfor %}{% endfor %}').render!('context' => ContextDrop.new, 'dummy' => [1])
-    assert_equal '123', Liquid::Template.parse('{%for a in dummy%}{%for a in dummy%}{% for i in context.scopes_as_array %}{{i}}{% endfor %}{% endfor %}{% endfor %}').render!('context' => ContextDrop.new, 'dummy' => [1])
-  end
-
   def test_access_context_from_drop
     assert_equal '123', Liquid::Template.parse('{%for a in dummy%}{{ context.loop_pos }}{% endfor %}').render!('context' => ContextDrop.new, 'dummy' => [1, 2, 3])
   end
@@ -243,7 +208,7 @@ class DropsTest < Minitest::Test
   end
 
   def test_some_enumerable_methods_still_get_invoked
-    [:count, :max].each do |method|
+    [ :count, :max ].each do |method|
       assert_equal "3", Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => RealEnumerableDrop.new)
       assert_equal "3", Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => RealEnumerableDrop.new)
       assert_equal "3", Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => EnumerableDrop.new)
@@ -252,7 +217,7 @@ class DropsTest < Minitest::Test
 
     assert_equal "yes", Liquid::Template.parse("{% if collection contains 3 %}yes{% endif %}").render!('collection' => RealEnumerableDrop.new)
 
-    [:min, :first].each do |method|
+    [ :min, :first ].each do |method|
       assert_equal "1", Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => RealEnumerableDrop.new)
       assert_equal "1", Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => RealEnumerableDrop.new)
       assert_equal "1", Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => EnumerableDrop.new)
@@ -272,11 +237,4 @@ class DropsTest < Minitest::Test
     assert_equal 'ProductDrop', Liquid::Template.parse("{{ product }}").render!('product' => ProductDrop.new)
     assert_equal 'EnumerableDrop', Liquid::Template.parse('{{ collection }}').render!('collection' => EnumerableDrop.new)
   end
-
-  def test_invokable_methods
-    assert_equal %w(to_liquid catchall user_input context texts).to_set, ProductDrop.invokable_methods
-    assert_equal %w(to_liquid scopes_as_array loop_pos scopes).to_set, ContextDrop.invokable_methods
-    assert_equal %w(to_liquid size max min first count).to_set, EnumerableDrop.invokable_methods
-    assert_equal %w(to_liquid max min sort count first).to_set, RealEnumerableDrop.invokable_methods
-  end
 end # DropsTest

test/integration/error_handling_test.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 class ErrorHandlingTest < Minitest::Test
@@ -85,14 +83,15 @@ class ErrorHandlingTest < Minitest::Test
 
   def test_with_line_numbers_adds_numbers_to_parser_errors
     err = assert_raises(SyntaxError) do
-      Liquid::Template.parse('
+      Liquid::Template.parse(%q(
           foobar
 
           {% "cat" | foobar %}
 
           bla
-        ',
-        line_numbers: true)
+        ),
+        line_numbers: true
+      )
     end
 
     assert_match(/Liquid syntax error \(line 4\)/, err.message)
@@ -100,14 +99,15 @@ class ErrorHandlingTest < Minitest::Test
 
   def test_with_line_numbers_adds_numbers_to_parser_errors_with_whitespace_trim
     err = assert_raises(SyntaxError) do
-      Liquid::Template.parse('
+      Liquid::Template.parse(%q(
           foobar
 
           {%- "cat" | foobar -%}
 
           bla
-        ',
-        line_numbers: true)
+        ),
+        line_numbers: true
+      )
     end
 
     assert_match(/Liquid syntax error \(line 4\)/, err.message)
@@ -122,7 +122,8 @@ class ErrorHandlingTest < Minitest::Test
         bla
             ',
       error_mode: :warn,
-      line_numbers: true)
+      line_numbers: true
+    )
 
     assert_equal ['Liquid syntax error (line 4): Unexpected character = in "1 =! 2"'],
       template.warnings.map(&:message)
@@ -138,7 +139,8 @@ class ErrorHandlingTest < Minitest::Test
           bla
                 ',
         error_mode: :strict,
-        line_numbers: true)
+        line_numbers: true
+      )
     end
 
     assert_equal 'Liquid syntax error (line 4): Unexpected character = in "1 =! 2"', err.message
@@ -155,7 +157,8 @@ class ErrorHandlingTest < Minitest::Test
 
           bla
                 ',
-        line_numbers: true)
+        line_numbers: true
+      )
     end
 
     assert_equal "Liquid syntax error (line 5): Unknown tag 'foo'", err.message
@@ -202,7 +205,7 @@ class ErrorHandlingTest < Minitest::Test
   def test_default_exception_renderer_with_internal_error
     template = Liquid::Template.parse('This is a runtime error: {{ errors.runtime_error }}', line_numbers: true)
 
-    output = template.render('errors' => ErrorDrop.new)
+    output = template.render({ 'errors' => ErrorDrop.new })
 
     assert_equal 'This is a runtime error: Liquid error (line 1): internal', output
     assert_equal [Liquid::InternalError], template.errors.map(&:class)
@@ -211,13 +214,10 @@ class ErrorHandlingTest < Minitest::Test
   def test_setting_default_exception_renderer
     old_exception_renderer = Liquid::Template.default_exception_renderer
     exceptions = []
-    Liquid::Template.default_exception_renderer = ->(e) {
-      exceptions << e
-      ''
-    }
+    Liquid::Template.default_exception_renderer = ->(e) { exceptions << e; '' }
     template = Liquid::Template.parse('This is a runtime error: {{ errors.argument_error }}')
 
-    output = template.render('errors' => ErrorDrop.new)
+    output = template.render({ 'errors' => ErrorDrop.new })
 
     assert_equal 'This is a runtime error: ', output
     assert_equal [Liquid::ArgumentError], template.errors.map(&:class)
@@ -228,10 +228,7 @@ class ErrorHandlingTest < Minitest::Test
   def test_exception_renderer_exposing_non_liquid_error
     template = Liquid::Template.parse('This is a runtime error: {{ errors.runtime_error }}', line_numbers: true)
     exceptions = []
-    handler = ->(e) {
-      exceptions << e
-      e.cause
-    }
+    handler = ->(e) { exceptions << e; e.cause }
 
     output = template.render({ 'errors' => ErrorDrop.new }, exception_renderer: handler)
 
@@ -242,7 +239,7 @@ class ErrorHandlingTest < Minitest::Test
   end
 
   class TestFileSystem
-    def read_template_file(_template_path)
+    def read_template_file(template_path)
       "{{ errors.argument_error }}"
     end
   end

test/integration/filter_test.rb

@@ -1,26 +1,24 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 module MoneyFilter
   def money(input)
-    format(' %d$ ', input)
+    sprintf(' %d$ ', input)
   end
 
   def money_with_underscore(input)
-    format(' %d$ ', input)
+    sprintf(' %d$ ', input)
   end
 end
 
 module CanadianMoneyFilter
   def money(input)
-    format(' %d$ CAD ', input)
+    sprintf(' %d$ CAD ', input)
   end
 end
 
 module SubstituteFilter
   def substitute(input, params = {})
-    input.gsub(/%\{(\w+)\}/) { |_match| params[Regexp.last_match(1)] }
+    input.gsub(/%\{(\w+)\}/) { |match| params[$1] }
   end
 end
 
@@ -28,7 +26,7 @@ class FiltersTest < Minitest::Test
   include Liquid
 
   module OverrideObjectMethodFilter
-    def tap(_input)
+    def tap(input)
       "tap overridden"
     end
   end
@@ -151,7 +149,7 @@ class FiltersTest < Minitest::Test
     assert_equal "tap overridden", Template.parse("{{var | tap}}").render!({ 'var' => 1000 }, filters: [OverrideObjectMethodFilter])
 
     # tap still treated as a non-existent filter
-    assert_equal "1000", Template.parse("{{var | tap}}").render!('var' => 1000)
+    assert_equal "1000", Template.parse("{{var | tap}}").render!({ 'var' => 1000 })
   end
 end
 

test/integration/hash_ordering_test.rb

@@ -1,17 +1,15 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 class HashOrderingTest < Minitest::Test
   module MoneyFilter
     def money(input)
-      format(' %d$ ', input)
+      sprintf(' %d$ ', input)
     end
   end
 
   module CanadianMoneyFilter
     def money(input)
-      format(' %d$ CAD ', input)
+      sprintf(' %d$ CAD ', input)
     end
   end
 

test/integration/output_test.rb

@@ -1,9 +1,7 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 module FunnyFilter
-  def make_funny(_input)
+  def make_funny(input)
     'LOL'
   end
 
@@ -34,7 +32,7 @@ class OutputTest < Minitest::Test
   def setup
     @assigns = {
       'best_cars' => 'bmw',
-      'car' => { 'bmw' => 'good', 'gm' => 'bad' },
+      'car' => { 'bmw' => 'good', 'gm' => 'bad' }
     }
   end
 

test/integration/parse_tree_visitor_test.rb

@@ -227,7 +227,7 @@ class ParseTreeVisitorTest < Minitest::Test
       [[nil, [
         [nil, [[nil, [["other", []]]]]],
         ["test", []],
-        ["xs", []],
+        ["xs", []]
       ]]],
       traversal(%({% for x in xs offset: test %}{{ other }}{% endfor %})).visit
     )

test/integration/parsing_quirks_test.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 class ParsingQuirksTest < Minitest::Test

test/integration/render_profiling_test.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 class RenderProfilingTest < Minitest::Test
@@ -130,7 +128,7 @@ class RenderProfilingTest < Minitest::Test
     t.render!
 
     timing_count = 0
-    t.profiler.each do |_timing|
+    t.profiler.each do |timing|
       timing_count += 1
     end
 
@@ -147,7 +145,7 @@ class RenderProfilingTest < Minitest::Test
 
   def test_profiling_marks_children_of_for_blocks
     t = Template.parse("{% for item in collection %} {{ item }} {% endfor %}", profile: true)
-    t.render!("collection" => ["one", "two"])
+    t.render!({ "collection" => ["one", "two"] })
 
     assert_equal 1, t.profiler.length
     # Will profile each invocation of the for block

test/integration/security_test.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 module SecurityFilter

test/integration/standard_filter_test.rb

@@ -1,5 +1,4 @@
 # encoding: utf-8
-# frozen_string_literal: true
 
 require 'test_helper'
 
@@ -18,7 +17,7 @@ class TestThing
     "woot: #{@foo}"
   end
 
-  def [](_whatever)
+  def [](whatever)
     to_s
   end
 
@@ -38,7 +37,7 @@ class TestEnumerable < Liquid::Drop
   include Enumerable
 
   def each(&block)
-    [{ "foo" => 1, "bar" => 2 }, { "foo" => 2, "bar" => 1 }, { "foo" => 3, "bar" => 3 }].each(&block)
+    [ { "foo" => 1, "bar" => 2 }, { "foo" => 2, "bar" => 1 }, { "foo" => 3, "bar" => 3 } ].each(&block)
   end
 end
 
@@ -209,14 +208,14 @@ class StandardFiltersTest < Minitest::Test
       { "handle" => "beta" },
       { "price" => 1, "handle" => "gamma" },
       { "handle" => "delta" },
-      { "price" => 2, "handle" => "epsilon" },
+      { "price" => 2, "handle" => "epsilon" }
     ]
     expectation = [
       { "price" => 1, "handle" => "gamma" },
       { "price" => 2, "handle" => "epsilon" },
       { "price" => 4, "handle" => "alpha" },
       { "handle" => "delta" },
-      { "handle" => "beta" },
+      { "handle" => "beta" }
     ]
     assert_equal expectation, @filters.sort(input, "price")
   end
@@ -237,14 +236,14 @@ class StandardFiltersTest < Minitest::Test
       { "handle" => "beta" },
       { "price" => "1", "handle" => "gamma" },
       { "handle" => "delta" },
-      { "price" => 2, "handle" => "epsilon" },
+      { "price" => 2, "handle" => "epsilon" }
     ]
     expectation = [
       { "price" => "1", "handle" => "gamma" },
       { "price" => 2, "handle" => "epsilon" },
       { "price" => "4", "handle" => "alpha" },
       { "handle" => "delta" },
-      { "handle" => "beta" },
+      { "handle" => "beta" }
     ]
     assert_equal expectation, @filters.sort_natural(input, "price")
   end
@@ -257,7 +256,7 @@ class StandardFiltersTest < Minitest::Test
       { "fake" => "t" },
       { "key" => "a" },
       { "key" => "b" },
-      { "key" => "c" },
+      { "key" => "c" }
     ]
     expectation = [
       { "key" => "a" },
@@ -266,7 +265,7 @@ class StandardFiltersTest < Minitest::Test
       { "key" => "X" },
       { "key" => "Y" },
       { "key" => "Z" },
-      { "fake" => "t" },
+      { "fake" => "t" }
     ]
     assert_equal expectation, @filters.sort_natural(input, "key")
     assert_equal ["a", "b", "c", "X", "Y", "Z"], @filters.sort_natural(["X", "Y", "Z", "a", "b", "c"])
@@ -280,7 +279,7 @@ class StandardFiltersTest < Minitest::Test
     foo = [
       [1],
       [2],
-      [3],
+      [3]
     ]
 
     assert_raises Liquid::ArgumentError do
@@ -296,7 +295,7 @@ class StandardFiltersTest < Minitest::Test
     foo = [
       [1],
       [2],
-      [3],
+      [3]
     ]
 
     assert_raises Liquid::ArgumentError do
@@ -305,7 +304,7 @@ class StandardFiltersTest < Minitest::Test
   end
 
   def test_legacy_sort_hash
-    assert_equal [{ a: 1, b: 2 }], @filters.sort(a: 1, b: 2)
+    assert_equal [{ a: 1, b: 2 }], @filters.sort({ a: 1, b: 2 })
   end
 
   def test_numerical_vs_lexicographical_sort
@@ -331,7 +330,7 @@ class StandardFiltersTest < Minitest::Test
     foo = [
       [1],
       [2],
-      [3],
+      [3]
     ]
 
     assert_raises Liquid::ArgumentError do
@@ -347,7 +346,7 @@ class StandardFiltersTest < Minitest::Test
     foo = [
       [1],
       [2],
-      [3],
+      [3]
     ]
 
     assert_raises Liquid::ArgumentError do
@@ -381,7 +380,7 @@ class StandardFiltersTest < Minitest::Test
 
   def test_map_on_hashes
     assert_template_result "4217", '{{ thing | map: "foo" | map: "bar" }}',
-      "thing" => { "foo" => [{ "bar" => 42 }, { "bar" => 17 }] }
+      "thing" => { "foo" => [ { "bar" => 42 }, { "bar" => 17 } ] }
   end
 
   def test_legacy_map_on_hashes_with_dynamic_key
@@ -398,7 +397,7 @@ class StandardFiltersTest < Minitest::Test
 
   def test_map_over_proc
     drop = TestDrop.new
-    p = proc { drop }
+    p = proc{ drop }
     templ = '{{ procs | map: "test" }}'
     assert_template_result "testfoo", templ, "procs" => [p]
   end
@@ -406,11 +405,11 @@ class StandardFiltersTest < Minitest::Test
   def test_map_over_drops_returning_procs
     drops = [
       {
-        "proc" => -> { "foo" },
+        "proc" => ->{ "foo" }
       },
       {
-        "proc" => -> { "bar" },
-      },
+        "proc" => ->{ "bar" }
+      }
     ]
     templ = '{{ drops | map: "proc" }}'
     assert_template_result "foobar", templ, "drops" => drops
@@ -424,7 +423,7 @@ class StandardFiltersTest < Minitest::Test
     foo = [
       [1],
       [2],
-      [3],
+      [3]
     ]
 
     assert_raises Liquid::ArgumentError do
@@ -436,7 +435,7 @@ class StandardFiltersTest < Minitest::Test
     foo = [
       [1],
       [2],
-      [3],
+      [3]
     ]
     assert_raises Liquid::ArgumentError do
       @filters.map(foo, nil)
@@ -698,12 +697,12 @@ class StandardFiltersTest < Minitest::Test
       { "handle" => "alpha", "ok" => true },
       { "handle" => "beta", "ok" => false },
       { "handle" => "gamma", "ok" => false },
-      { "handle" => "delta", "ok" => true },
+      { "handle" => "delta", "ok" => true }
     ]
 
     expectation = [
       { "handle" => "alpha", "ok" => true },
-      { "handle" => "delta", "ok" => true },
+      { "handle" => "delta", "ok" => true }
     ]
 
     assert_equal expectation, @filters.where(input, "ok", true)
@@ -715,12 +714,12 @@ class StandardFiltersTest < Minitest::Test
       { "handle" => "alpha", "ok" => true },
       { "handle" => "beta" },
       { "handle" => "gamma" },
-      { "handle" => "delta", "ok" => true },
+      { "handle" => "delta", "ok" => true }
     ]
 
     expectation = [
       { "handle" => "alpha", "ok" => true },
-      { "handle" => "delta", "ok" => true },
+      { "handle" => "delta", "ok" => true }
     ]
 
     assert_equal expectation, @filters.where(input, "ok", true)
@@ -741,7 +740,7 @@ class StandardFiltersTest < Minitest::Test
     input = [
       { "message" => "Bonjour!", "language" => "French" },
       { "message" => "Hello!", "language" => "English" },
-      { "message" => "Hallo!", "language" => "German" },
+      { "message" => "Hallo!", "language" => "German" }
     ]
 
     assert_equal [{ "message" => "Bonjour!", "language" => "French" }], @filters.where(input, "language", "French")
@@ -759,7 +758,7 @@ class StandardFiltersTest < Minitest::Test
       { "foo" => false },
       { "foo" => true },
       { "foo" => "for sure" },
-      { "bar" => true },
+      { "bar" => true }
     ]
 
     assert_equal [{ "foo" => true }, { "foo" => "for sure" }], @filters.where(input, "foo")

test/integration/tags/break_tag_test.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 class BreakTagTest < Minitest::Test

test/integration/tags/continue_tag_test.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 class ContinueTagTest < Minitest::Test

test/integration/tags/echo_test.rb

@@ -1,13 +0,0 @@
-# frozen_string_literal: true
-
-require 'test_helper'
-
-class EchoTest < Minitest::Test
-  include Liquid
-
-  def test_echo_outputs_its_input
-    assert_template_result('BAR', <<~LIQUID, 'variable-name' => 'bar')
-      {%- echo variable-name | upcase -%}
-    LIQUID
-  end
-end

test/integration/tags/for_tag_test.rb

@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'
 
 class ThingWithValue < Liquid::Drop
@@ -25,16 +23,16 @@ class ForTagTest < Minitest::Test
   yo
 
 HERE
-    template = <<~HERE
-      {%for item in array%}
-        yo
-      {%endfor%}
-    HERE
+    template = <<HERE
+{%for item in array%}
+  yo
+{%endfor%}
+HERE
     assert_template_result(expected, template, 'array' => [1, 2, 3])
   end
 
   def test_for_reversed
-    assigns = { 'array' => [1, 2, 3] }
+    assigns = { 'array' => [ 1, 2, 3] }
     assert_template_result('321', '{%for item in array reversed %}{{item}}{%endfor%}', assigns)
   end
 
@@ -370,6 +368,23 @@ HERE
     assert_template_result(expected, template, assigns)
   end
 
+  def test_overwriting_internal_variable
+    template = <<-HEREDOC
+    {% assign forloop = 'first' %}
+
+    {% for item in items %}
+      {{ forloop }}
+      {% assign forloop = 'second' %}
+      {{ forloop }}
+    {% endfor %}
+
+    {{ forloop }}
+    HEREDOC
+
+    result = Liquid::Template.parse(template).render('items' => '1')
+    assert_equal 'Liquid::ForloopDrop Liquid::ForloopDrop second', result.split.map(&:strip).join(' ')
+  end
+
   class LoaderDrop < Liquid::Drop
     attr_accessor :each_called, :load_slice_called