Remove jruby and truffleruby testing

* Changes static registers to not be frozen

* Add frozen test to static registers

.rubocop.yml

@@ -1,5 +1,5 @@
 inherit_from:
-  - https://shopify.github.io/ruby-style-guide/rubocop.yml
+  - 'https://shopify.github.io/ruby-style-guide/rubocop.yml'
   - .rubocop_todo.yml
 
 require: rubocop-performance
@@ -10,7 +10,7 @@ Performance:
 AllCops:
   Exclude:
     - 'vendor/bundle/**/*'
-      
+
 Naming/MethodName:
   Exclude:
-    - 'example/server/liquid_servlet.rb'
+    - 'example/server/liquid_servlet.rb'

.rubocop_todo.yml

@@ -1,92 +1,17 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2019-08-29 12:16:25 +1000 using RuboCop version 0.74.0.
+# on 2019-09-11 06:34:25 +1000 using RuboCop version 0.74.0.
 # 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: 13
-# Cop supports --auto-correct.
-# Configuration parameters: AllowMultipleStyles, EnforcedHashRocketStyle, EnforcedColonStyle, EnforcedLastArgumentHashStyle.
-# SupportedHashRocketStyles: key, separator, table
-# SupportedColonStyles: key, separator, table
-# SupportedLastArgumentHashStyles: always_inspect, always_ignore, ignore_implicit, ignore_explicit
-Layout/AlignHash:
-  Exclude:
-    - 'lib/liquid/condition.rb'
-    - 'lib/liquid/expression.rb'
-    - 'performance/shopify/comment_form.rb'
-    - 'performance/shopify/database.rb'
-    - 'performance/shopify/paginate.rb'
-    - 'test/unit/context_unit_test.rb'
-
-# Offense count: 3
-# Cop supports --auto-correct.
-# Configuration parameters: AllowForAlignment, AllowBeforeTrailingComments, ForceEqualSignAlignment.
-Layout/ExtraSpacing:
-  Exclude:
-    - 'performance/shopify/paginate.rb'
-
-# Offense count: 5
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle.
-# SupportedStyles: 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: 4
-# Cop supports --auto-correct.
-# Configuration parameters: AllowForAlignment.
-Layout/SpaceAroundOperators:
-  Exclude:
-    - 'lib/liquid/condition.rb'
-    - 'performance/shopify/paginate.rb'
-
-# Offense count: 9
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, EnforcedStyleForEmptyBraces.
-# SupportedStyles: space, no_space
-# SupportedStylesForEmptyBraces: space, no_space
-Layout/SpaceBeforeBlockBraces:
-  Exclude:
-    - 'example/server/server.rb'
-    - 'lib/liquid/variable.rb'
-    - 'test/integration/drop_test.rb'
-    - 'test/integration/standard_filter_test.rb'
-    - 'test/integration/tags/if_else_tag_test.rb'
-
-# Offense count: 19
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, EnforcedStyleForEmptyBrackets.
-# SupportedStyles: space, no_space, compact
-# SupportedStylesForEmptyBrackets: space, no_space
-Layout/SpaceInsideArrayLiteralBrackets:
-  Exclude:
-    - 'test/integration/drop_test.rb'
-    - 'test/integration/standard_filter_test.rb'
-    - 'test/integration/tags/for_tag_test.rb'
-    - 'test/integration/tags/include_tag_test.rb'
-    - 'test/integration/tags/standard_tag_test.rb'
-    - 'test/unit/context_unit_test.rb'
-
 # Offense count: 2
 Lint/AmbiguousOperator:
   Exclude:
     - 'test/unit/condition_unit_test.rb'
 
-# Offense count: 16
+# Offense count: 21
 # Configuration parameters: AllowSafeAssignment.
 Lint/AssignmentInCondition:
   Exclude:
@@ -95,7 +20,6 @@ Lint/AssignmentInCondition:
     - 'lib/liquid/standardfilters.rb'
     - 'lib/liquid/tags/for.rb'
     - 'lib/liquid/tags/if.rb'
-    - 'lib/liquid/tags/include.rb'
     - 'lib/liquid/tags/raw.rb'
     - 'lib/liquid/variable.rb'
     - 'performance/profile.rb'
@@ -110,36 +34,6 @@ Lint/InheritException:
   Exclude:
     - 'lib/liquid/interrupts.rb'
 
-# Offense count: 10
-# Cop supports --auto-correct.
-# Configuration parameters: IgnoreEmptyBlocks, AllowUnusedKeywordArguments.
-Lint/UnusedBlockArgument:
-  Exclude:
-    - 'lib/liquid/condition.rb'
-    - 'lib/liquid/context.rb'
-    - 'lib/liquid/document.rb'
-    - 'lib/liquid/parse_context.rb'
-    - 'lib/liquid/template.rb'
-    - 'performance/shopify/json_filter.rb'
-    - 'test/integration/filter_test.rb'
-    - 'test/integration/render_profiling_test.rb'
-    - 'test/integration/variable_test.rb'
-    - 'test/unit/condition_unit_test.rb'
-
-# Offense count: 12
-# Cop supports --auto-correct.
-# Configuration parameters: AllowUnusedKeywordArguments, IgnoreEmptyMethods.
-Lint/UnusedMethodArgument:
-  Exclude:
-    - 'example/server/liquid_servlet.rb'
-    - 'test/integration/blank_test.rb'
-    - 'test/integration/error_handling_test.rb'
-    - 'test/integration/filter_test.rb'
-    - 'test/integration/output_test.rb'
-    - 'test/integration/standard_filter_test.rb'
-    - 'test/integration/tags/include_tag_test.rb'
-    - 'test/unit/strainer_unit_test.rb'
-
 # Offense count: 2
 Lint/UselessAssignment:
   Exclude:
@@ -151,7 +45,7 @@ Lint/Void:
   Exclude:
     - 'lib/liquid/parse_context.rb'
 
-# Offense count: 95
+# Offense count: 98
 # Cop supports --auto-correct.
 # Configuration parameters: AutoCorrect, AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
 # URISchemes: http, https
@@ -177,39 +71,6 @@ Naming/ConstantName:
     - 'performance/shopify/paginate.rb'
     - 'test/integration/tags/include_tag_test.rb'
 
-# Offense count: 2
-# Configuration parameters: .
-# SupportedStyles: snake_case, camelCase
-Naming/MethodName:
-  EnforcedStyle: snake_case
-
-# Offense count: 3
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle.
-# SupportedStyles: always, conditionals
-Style/AndOr:
-  Exclude:
-    - 'lib/liquid/i18n.rb'
-    - 'lib/liquid/tags/table_row.rb'
-    - 'lib/liquid/tokenizer.rb'
-
-# Offense count: 40
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle.
-# SupportedStyles: braces, no_braces, context_dependent
-Style/BracesAroundHashParameters:
-  Exclude:
-    - 'test/integration/error_handling_test.rb'
-    - 'test/integration/filter_test.rb'
-    - 'test/integration/render_profiling_test.rb'
-    - 'test/integration/standard_filter_test.rb'
-    - 'test/integration/tags/echo_test.rb'
-    - 'test/integration/tags/increment_tag_test.rb'
-    - 'test/integration/tags/standard_tag_test.rb'
-    - 'test/integration/template_test.rb'
-    - 'test/unit/condition_unit_test.rb'
-    - 'test/unit/context_unit_test.rb'
-
 # Offense count: 5
 Style/ClassVars:
   Exclude:
@@ -217,195 +78,17 @@ Style/ClassVars:
     - 'lib/liquid/strainer.rb'
     - 'lib/liquid/template.rb'
 
-# Offense count: 2
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SingleLineConditionsOnly, IncludeTernaryExpressions.
-# SupportedStyles: assign_to_condition, assign_inside_condition
-Style/ConditionalAssignment:
-  Exclude:
-    - 'lib/liquid/errors.rb'
-    - 'performance/shopify/shop_filter.rb'
-
 # Offense count: 1
 # Configuration parameters: AllowCoercion.
 Style/DateTime:
   Exclude:
     - 'test/unit/context_unit_test.rb'
 
-# Offense count: 2
-# Cop supports --auto-correct.
-Style/EachWithObject:
-  Exclude:
-    - 'performance/shopify/database.rb'
-
-# Offense count: 1
-# Cop supports --auto-correct.
-Style/EmptyCaseCondition:
-  Exclude:
-    - 'lib/liquid/lexer.rb'
-
-# Offense count: 1
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle.
-# SupportedStyles: each, for
-Style/For:
-  Exclude:
-    - 'performance/shopify/shop_filter.rb'
-
 # Offense count: 9
 # Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle.
-# SupportedStyles: format, sprintf, percent
-Style/FormatString:
-  Exclude:
-    - 'example/server/example_servlet.rb'
-    - 'performance/shopify/money_filter.rb'
-    - 'performance/shopify/weight_filter.rb'
-    - 'test/integration/filter_test.rb'
-    - 'test/integration/hash_ordering_test.rb'
-
-# Offense count: 115
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle.
-# SupportedStyles: always, never
-Style/FrozenStringLiteralComment:
-  Enabled: false
-
-# Offense count: 30
-# Cop supports --auto-correct.
-# Configuration parameters: IgnoreMacros, IgnoredMethods, IncludedMacros, AllowParenthesesInMultilineCall, AllowParenthesesInChaining, AllowParenthesesInCamelCaseMethod, EnforcedStyle.
-# SupportedStyles: require_parentheses, omit_parentheses
-Style/MethodCallWithArgsParentheses:
-  Exclude:
-    - 'Gemfile'
-    - 'Rakefile'
-    - 'lib/liquid/block_body.rb'
-    - 'lib/liquid/parser.rb'
-    - 'lib/liquid/tags/for.rb'
-    - 'liquid.gemspec'
-    - 'performance/shopify/database.rb'
-    - 'performance/shopify/liquid.rb'
-    - 'test/test_helper.rb'
-    - 'test/unit/condition_unit_test.rb'
-    - 'test/unit/tags/if_tag_unit_test.rb'
-
-# 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: 52
-# Cop supports --auto-correct.
-Style/PerlBackrefs:
-  Enabled: false
-
-# Offense count: 33
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle.
-# SupportedStyles: compact, exploded
-Style/RaiseArgs:
-  Enabled: false
-
-# Offense count: 1
-# Cop supports --auto-correct.
-Style/RedundantSelf:
-  Exclude:
-    - 'lib/liquid/strainer.rb'
-
-# Offense count: 5
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, AllowInnerSlashes.
-# SupportedStyles: slashes, percent_r, mixed
-Style/RegexpLiteral:
-  Exclude:
-    - 'lib/liquid/file_system.rb'
-    - 'lib/liquid/standardfilters.rb'
-    - 'performance/shopify/shop_filter.rb'
-    - 'test/unit/condition_unit_test.rb'
-
-# Offense count: 3
-# Cop supports --auto-correct.
-# Configuration parameters: ConvertCodeThatCanStartToReturnNil, Whitelist.
-# Whitelist: present?, blank?, presence, try, try!
-Style/SafeNavigation:
-  Exclude:
-    - 'lib/liquid/drop.rb'
-    - 'lib/liquid/strainer.rb'
-    - 'lib/liquid/tokenizer.rb'
-
-# Offense count: 10
-# Cop supports --auto-correct.
 # Configuration parameters: AllowAsExpressionSeparator.
 Style/Semicolon:
   Exclude:
-    - 'performance/shopify/database.rb'
     - 'test/integration/error_handling_test.rb'
     - 'test/integration/template_test.rb'
     - 'test/unit/context_unit_test.rb'
-
-# Offense count: 1
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle.
-# SupportedStyles: use_perl_names, use_english_names
-Style/SpecialGlobalVars:
-  Exclude:
-    - 'performance/shopify/liquid.rb'
-
-# Offense count: 2
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle.
-# SupportedStyles: single_quotes, double_quotes
-Style/StringLiteralsInInterpolation:
-  Exclude:
-    - 'performance/shopify/tag_filter.rb'
-
-# 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: 21
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyleForMultiline.
-# SupportedStylesForMultiline: comma, consistent_comma, no_comma
-Style/TrailingCommaInArrayLiteral:
-  Exclude:
-    - 'lib/liquid/parse_tree_visitor.rb'
-    - 'lib/liquid/tags/include.rb'
-    - 'test/integration/parse_tree_visitor_test.rb'
-    - 'test/integration/standard_filter_test.rb'
-
-# Offense count: 9
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyleForMultiline.
-# SupportedStylesForMultiline: comma, consistent_comma, no_comma
-Style/TrailingCommaInHashLiteral:
-  Exclude:
-    - 'lib/liquid/condition.rb'
-    - 'lib/liquid/lexer.rb'
-    - 'lib/liquid/standardfilters.rb'
-    - 'performance/shopify/comment_form.rb'
-    - 'performance/shopify/database.rb'
-    - 'performance/shopify/paginate.rb'
-    - 'performance/theme_runner.rb'
-    - 'test/integration/output_test.rb'
-    - 'test/unit/context_unit_test.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'

.travis.yml

@@ -7,8 +7,6 @@ rvm:
   - &latest_ruby 2.6
   - 2.7
   - ruby-head
-  - jruby-head
-  - truffleruby
 
 matrix:
   include:
@@ -17,8 +15,6 @@ matrix:
       name: Profiling Memory Usage
   allow_failures:
     - rvm: ruby-head
-    - rvm: jruby-head
-    - rvm: truffleruby
 
 branches:
   only:

Gemfile

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
 git_source(:github) do |repo_name|
   "https://github.com/#{repo_name}.git"

Rakefile

@@ -1,18 +1,20 @@
+# 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
@@ -25,7 +27,7 @@ task :rubocop do
   end
 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
@@ -47,7 +49,7 @@ task :test do
   end
 end
 
-task gem: :build
+task(gem: :build)
 task :build do
   system "gem build liquid.gemspec"
 end
@@ -94,7 +96,7 @@ 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

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

example/server/liquid_servlet.rb

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

example/server/server.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'webrick'
 require 'rexml/document'
 
@@ -8,5 +10,5 @@ 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

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Copyright (c) 2005 Tobias Luetke
 #
 # Permission is hereby granted, free of charge, to any person obtaining
@@ -21,10 +23,10 @@
 
 module Liquid
   FilterSeparator             = /\|/
-  ArgumentSeparator           = ','.freeze
-  FilterArgumentSeparator     = ':'.freeze
-  VariableAttributeSeparator  = '.'.freeze
-  WhitespaceControl           = '-'.freeze
+  ArgumentSeparator           = ','
+  FilterArgumentSeparator     = ':'
+  VariableAttributeSeparator  = '.'
+  WhitespaceControl           = '-'
   TagStart                    = /\{\%/
   TagEnd                      = /\%\}/
   VariableSignature           = /\(?[\w\-\.\[\]]\)?/
@@ -76,6 +78,7 @@ 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

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Block < Tag
     MAX_DEPTH = 100
@@ -27,16 +29,16 @@ module Liquid
     end
 
     def unknown_tag(tag, _params, _tokens)
-      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,
+      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",
           tag: tag,
           block_name: block_name,
-          block_delimiter: block_delimiter))
+          block_delimiter: block_delimiter)
       else
-        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unknown_tag".freeze, tag: tag))
+        raise SyntaxError, parse_context.locale.t("errors.syntax.unknown_tag", tag: tag)
       end
     end
 
@@ -52,7 +54,7 @@ module Liquid
 
     def parse_body(body, tokens)
       if parse_context.depth >= MAX_DEPTH
-        raise StackLevelError, "Nesting too deep".freeze
+        raise StackLevelError, "Nesting too deep"
       end
       parse_context.depth += 1
       begin
@@ -61,7 +63,7 @@ module Liquid
 
           return false if end_tag_name == block_delimiter
           unless end_tag_name
-            raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_never_closed".freeze, block_name: block_name))
+            raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed", block_name: block_name)
           end
 
           # this tag is not registered with the system

lib/liquid/block_body.rb

@@ -1,11 +1,13 @@
+# 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
     ContentOfVariable = /\A#{VariableStart}#{WhitespaceControl}?(.*?)#{WhitespaceControl}?#{VariableEnd}\z/om
     WhitespaceOrNothing = /\A\s*\z/
-    TAGSTART = "{%".freeze
-    VARSTART = "{{".freeze
+    TAGSTART = "{%"
+    VARSTART = "{{"
 
     attr_reader :nodelist
 
@@ -32,8 +34,8 @@ module Liquid
             # caller raise a syntax error
             return yield token, token
           end
-          tag_name = $1
-          markup = $2
+          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
@@ -58,16 +60,16 @@ module Liquid
           unless token =~ FullToken
             raise_missing_tag_terminator(token, parse_context)
           end
-          tag_name = $2
-          markup = $4
+          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 += $1.count("\n".freeze) + $3.count("\n".freeze)
+            parse_context.line_number += Regexp.last_match(1).count("\n") + Regexp.last_match(3).count("\n")
           end
 
-          if tag_name == 'liquid'.freeze
+          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
@@ -101,7 +103,7 @@ 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
@@ -113,7 +115,7 @@ module Liquid
     end
 
     def render(context)
-      render_to_output_buffer(context, '')
+      render_to_output_buffer(context, +'')
     end
 
     def render_to_output_buffer(context, output)
@@ -129,7 +131,7 @@ module Liquid
         when Variable
           render_node(context, output, node)
         when Block
-          render_node(context, node.blank? ? '' : output, node)
+          render_node(context, node.blank? ? +'' : output, node)
           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
@@ -163,7 +165,7 @@ module Liquid
     def raise_if_resource_limits_reached(context, length)
       context.resource_limits.render_length += length
       return unless context.resource_limits.reached?
-      raise MemoryError.new("Memory limits exceeded".freeze)
+      raise MemoryError, "Memory limits exceeded"
     end
 
     def create_variable(token, parse_context)
@@ -175,11 +177,11 @@ module Liquid
     end
 
     def raise_missing_tag_terminator(token, parse_context)
-      raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_termination".freeze, token: token, tag_end: TagEnd.inspect))
+      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_termination", token: token, tag_end: TagEnd.inspect)
     end
 
     def raise_missing_variable_terminator(token, parse_context)
-      raise SyntaxError.new(parse_context.locale.t("errors.syntax.variable_termination".freeze, token: token, tag_end: VariableEnd.inspect))
+      raise SyntaxError, parse_context.locale.t("errors.syntax.variable_termination", token: token, tag_end: VariableEnd.inspect)
     end
 
     def registered_tags

lib/liquid/condition.rb

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

lib/liquid/context.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Context keeps the variable stack and resolves variables, as well as keywords
   #
@@ -16,18 +18,17 @@ module Liquid
     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_registers: {}, static_environments: {})
-      new(environments, outer_scope, registers, rethrow_errors, resource_limits, static_registers, static_environments)
+    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_registers = {}, static_environments = {})
+    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
-      @static_registers    = static_registers.freeze
       @errors              = []
       @partial             = false
       @strict_variables    = false
@@ -35,11 +36,9 @@ module Liquid
       @base_scope_depth    = 0
       squash_instance_assigns_with_environments
 
-      @this_stack_used = false
-
       self.exception_renderer = Template.default_exception_renderer
       if rethrow_errors
-        self.exception_renderer = ->(e) { raise }
+        self.exception_renderer = ->(_e) { raise }
       end
 
       @interrupts = []
@@ -122,19 +121,11 @@ module Liquid
     #   end
     #
     #   context['var]  #=> nil
-    def stack(new_scope = nil)
-      old_stack_used = @this_stack_used
-      if new_scope
-        push(new_scope)
-        @this_stack_used = true
-      else
-        @this_stack_used = false
-      end
-
+    def stack(new_scope = {})
+      push(new_scope)
       yield
     ensure
-      pop if @this_stack_used
-      @this_stack_used = old_stack_used
+      pop
     end
 
     # Creates a new context inheriting resource limits, filters, environment etc.,
@@ -145,7 +136,7 @@ module Liquid
       Context.build(
         resource_limits: resource_limits,
         static_environments: static_environments,
-        static_registers: static_registers
+        registers: StaticRegisters.new(registers)
       ).tap do |subcontext|
         subcontext.base_scope_depth = base_scope_depth + 1
         subcontext.exception_renderer = exception_renderer
@@ -162,10 +153,6 @@ module Liquid
 
     # Only allow String, Numeric, Hash, Array, Proc, Boolean or <tt>Liquid::Drop</tt>
     def []=(key, value)
-      unless @this_stack_used
-        @this_stack_used = true
-        push({})
-      end
       @scopes[0][key] = value
     end
 
@@ -215,7 +202,7 @@ module Liquid
       value = obj[key]
 
       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
@@ -246,7 +233,7 @@ module Liquid
     end
 
     def check_overflow
-      raise StackLevelError, "Nesting too deep".freeze if overflow?
+      raise StackLevelError, "Nesting too deep" if overflow?
     end
 
     def overflow?

lib/liquid/document.rb

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

lib/liquid/drop.rb

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

lib/liquid/errors.rb

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

lib/liquid/expression.rb

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

lib/liquid/extensions.rb

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

lib/liquid/file_system.rb

@@ -1,3 +1,5 @@
+# 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.
   #
@@ -44,7 +46,7 @@ module Liquid
   class LocalFileSystem
     attr_accessor :root
 
-    def initialize(root, pattern = "_%s.liquid".freeze)
+    def initialize(root, pattern = "_%s.liquid")
       @root = root
       @pattern = pattern
     end
@@ -57,9 +59,9 @@ module Liquid
     end
 
     def full_path(template_path)
-      raise FileSystemError, "Illegal template name '#{template_path}'" unless template_path =~ /\A[^.\/][a-zA-Z0-9_\/]+\z/
+      raise FileSystemError, "Illegal template name '#{template_path}'" unless template_path =~ %r{\A[^./][a-zA-Z0-9_/]+\z}
 
-      full_path = if template_path.include?('/'.freeze)
+      full_path = if template_path.include?('/')
         File.join(root, File.dirname(template_path), @pattern % File.basename(template_path))
       else
         File.join(root, @pattern % template_path)

lib/liquid/forloop_drop.rb

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

lib/liquid/i18n.rb

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

lib/liquid/interrupts.rb

@@ -1,10 +1,12 @@
+# 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".freeze
+      @message = message || "interrupt"
     end
   end
 

lib/liquid/lexer.rb

@@ -1,17 +1,19 @@
+# frozen_string_literal: true
+
 require "strscan"
 module Liquid
   class Lexer
     SPECIALS = {
-      '|'.freeze => :pipe,
-      '.'.freeze => :dot,
-      ':'.freeze => :colon,
-      ','.freeze => :comma,
-      '['.freeze => :open_square,
-      ']'.freeze => :close_square,
-      '('.freeze => :open_round,
-      ')'.freeze => :close_round,
-      '?'.freeze => :question,
-      '-'.freeze => :dash
+      '|' => :pipe,
+      '.' => :dot,
+      ':' => :colon,
+      ',' => :comma,
+      '[' => :open_square,
+      ']' => :close_square,
+      '(' => :open_round,
+      ')' => :close_round,
+      '?' => :question,
+      '-' => :dash,
     }.freeze
     IDENTIFIER = /[a-zA-Z_][\w-]*\??/
     SINGLE_STRING_LITERAL = /'[^\']*'/
@@ -31,13 +33,12 @@ module Liquid
       until @ss.eos?
         @ss.skip(WHITESPACE_OR_NOTHING)
         break if @ss.eos?
-        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]
+        tok = if t = @ss.scan(COMPARISON_OPERATOR) then [:comparison, t]
+        elsif t = @ss.scan(SINGLE_STRING_LITERAL) then [:string, t]
+        elsif t = @ss.scan(DOUBLE_STRING_LITERAL) then [:string, t]
+        elsif t = @ss.scan(NUMBER_LITERAL) then [:number, t]
+        elsif t = @ss.scan(IDENTIFIER) then [:id, t]
+        elsif t = @ss.scan(DOTDOT) then [:dotdot, t]
         else
           c = @ss.getch
           if s = SPECIALS[c]

lib/liquid/parse_context.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class ParseContext
     attr_accessor :locale, :line_number, :trim_whitespace, :depth
@@ -28,7 +30,7 @@ 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

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Parser
     def initialize(input)
@@ -51,7 +53,7 @@ module Liquid
       token = @tokens[@p]
       if token[0] == :id
         variable_signature
-      elsif SINGLE_TOKEN_EXPRESSION_TYPES.include? token[0]
+      elsif SINGLE_TOKEN_EXPRESSION_TYPES.include?(token[0])
         consume
       elsif token.first == :open_round
         consume
@@ -66,10 +68,10 @@ module Liquid
     end
 
     def argument
-      str = ""
+      str = +""
       # might be a keyword argument (identifier: expression)
       if look(:id) && look(:colon, 1)
-        str << consume << consume << ' '.freeze
+        str << consume << consume << ' '
       end
 
       str << expression

lib/liquid/parser_switching.rb

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

lib/liquid/partial_cache.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class PartialCache
     def self.load(template_name, context:, parse_context:)

lib/liquid/profiler.rb

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

lib/liquid/profiler/hooks.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class BlockBody
     def render_node_with_profiling(context, output, node)

lib/liquid/range_lookup.rb

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

lib/liquid/resource_limits.rb

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

lib/liquid/standardfilters.rb

@@ -1,20 +1,22 @@
+# frozen_string_literal: true
+
 require 'cgi'
 require 'bigdecimal'
 
 module Liquid
   module StandardFilters
     HTML_ESCAPE = {
-      '&'.freeze => '&'.freeze,
-      '>'.freeze => '>'.freeze,
-      '<'.freeze => '&lt;'.freeze,
-      '"'.freeze => '&quot;'.freeze,
-      "'".freeze => '&#39;'.freeze
+      '&' => '&amp;',
+      '>' => '&gt;',
+      '<' => '&lt;',
+      '"' => '&quot;',
+      "'" => '&#39;',
     }.freeze
     HTML_ESCAPE_ONCE_REGEXP = /["><']|&(?!([a-zA-Z]+|(#\d+));)/
     STRIP_HTML_BLOCKS = Regexp.union(
-      /<script.*?<\/script>/m,
+      %r{<script.*?</script>}m,
       /<!--.*?-->/m,
-      /<style.*?<\/style>/m
+      %r{<style.*?</style>}m
     )
     STRIP_HTML_TAGS = /<.*?>/m
 
@@ -72,7 +74,7 @@ module Liquid
     end
 
     # Truncate a string down to x characters
-    def truncate(input, length = 50, truncate_string = "...".freeze)
+    def truncate(input, length = 50, truncate_string = "...")
       return if input.nil?
       input_str = input.to_s
       length = Utils.to_integer(length)
@@ -82,13 +84,13 @@ module Liquid
       input_str.length > length ? input_str[0...l].concat(truncate_string_str) : input_str
     end
 
-    def truncatewords(input, words = 15, truncate_string = "...".freeze)
+    def truncatewords(input, words = 15, truncate_string = "...")
       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(" ".freeze).concat(truncate_string.to_s) : input
+      wordlist.length > l ? wordlist[0..l].join(" ").concat(truncate_string.to_s) : input
     end
 
     # Split input string into an array of substrings separated by given pattern.
@@ -113,7 +115,7 @@ module Liquid
     end
 
     def strip_html(input)
-      empty = ''.freeze
+      empty = ''
       result = input.to_s.gsub(STRIP_HTML_BLOCKS, empty)
       result.gsub!(STRIP_HTML_TAGS, empty)
       result
@@ -121,11 +123,11 @@ module Liquid
 
     # Remove all newlines from the string
     def strip_newlines(input)
-      input.to_s.gsub(/\r?\n/, ''.freeze)
+      input.to_s.gsub(/\r?\n/, '')
     end
 
     # Join elements of the array with certain character between them
-    def join(input, glue = ' '.freeze)
+    def join(input, glue = ' ')
       InputIterator.new(input).join(glue)
     end
 
@@ -220,7 +222,7 @@ module Liquid
       InputIterator.new(input).map do |e|
         e = e.call if e.is_a?(Proc)
 
-        if property == "to_liquid".freeze
+        if property == "to_liquid"
           e
         elsif e.respond_to?(:[])
           r = e[property]
@@ -250,23 +252,23 @@ module Liquid
     end
 
     # Replace occurrences of a string with another
-    def replace(input, string, replacement = ''.freeze)
+    def replace(input, string, replacement = '')
       input.to_s.gsub(string.to_s, replacement.to_s)
     end
 
     # Replace the first occurrences of a string with another
-    def replace_first(input, string, replacement = ''.freeze)
+    def replace_first(input, string, replacement = '')
       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, ''.freeze)
+      input.to_s.gsub(string.to_s, '')
     end
 
     # remove the first occurrences of a substring
     def remove_first(input, string)
-      input.to_s.sub(string.to_s, ''.freeze)
+      input.to_s.sub(string.to_s, '')
     end
 
     # add one string to another
@@ -276,7 +278,7 @@ module Liquid
 
     def concat(input, array)
       unless array.respond_to?(:to_ary)
-        raise ArgumentError.new("concat filter requires an array argument")
+        raise ArgumentError, "concat filter requires an array argument"
       end
       InputIterator.new(input).concat(array)
     end
@@ -288,7 +290,7 @@ 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".freeze)
+      input.to_s.gsub(/\n/, "<br />\n")
     end
 
     # Reformat a date using Ruby's core Time#strftime( string ) -> string
@@ -419,7 +421,7 @@ module Liquid
       result.is_a?(BigDecimal) ? result.to_f : result
     end
 
-    def default(input, default_value = ''.freeze)
+    def default(input, default_value = '')
       if !input || input.respond_to?(:empty?) && input.empty?
         Usage.increment("default_filter_received_false_value") if input == false # See https://github.com/Shopify/liquid/issues/1127
         default_value
@@ -431,7 +433,7 @@ module Liquid
     private
 
     def raise_property_error(property)
-      raise Liquid::ArgumentError.new("cannot select the property '#{property}'")
+      raise Liquid::ArgumentError, "cannot select the property '#{property}'"
     end
 
     def apply_operation(input, operand, operation)

lib/liquid/static_registers.rb

@@ -0,0 +1,36 @@
+# 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

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'set'
 
 module Liquid
@@ -27,7 +29,7 @@ module Liquid
 
     def self.add_filter(filter)
       raise ArgumentError, "Expected module but got: #{filter.class}" unless filter.is_a?(Module)
-      unless self.include?(filter)
+      unless 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(', ')}"
@@ -54,7 +56,7 @@ module Liquid
     def invoke(method, *args)
       if self.class.invokable?(method)
         send(method, *args)
-      elsif @context && @context.strict_filters
+      elsif @context&.strict_filters
         raise Liquid::UndefinedFilter, "undefined filter #{method}"
       else
         args.first

lib/liquid/tablerowloop_drop.rb

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

lib/liquid/tag.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Tag
     attr_reader :nodelist, :tag_name, :line_number, :parse_context
@@ -33,7 +35,7 @@ module Liquid
     end
 
     def render(_context)
-      ''.freeze
+      ''
     end
 
     # For backwards compatibility with custom tags. In a future release, the semantics

lib/liquid/tags/assign.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Assign sets a variable in your template.
   #
@@ -11,7 +13,7 @@ module Liquid
     Syntax = /(#{VariableSignature}+)\s*=\s*(.*)\s*/om
 
     def self.syntax_error_translation_key
-      "errors.syntax.assign".freeze
+      "errors.syntax.assign"
     end
 
     attr_reader :to, :from
@@ -19,10 +21,10 @@ module Liquid
     def initialize(tag_name, markup, options)
       super
       if markup =~ Syntax
-        @to = $1
-        @from = Variable.new($2, options)
+        @to = Regexp.last_match(1)
+        @from = Variable.new(Regexp.last_match(2), options)
       else
-        raise SyntaxError.new(options[:locale].t(self.class.syntax_error_translation_key))
+        raise SyntaxError, options[:locale].t(self.class.syntax_error_translation_key)
       end
     end
 
@@ -59,5 +61,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('assign'.freeze, Assign)
+  Template.register_tag('assign', Assign)
 end

lib/liquid/tags/break.rb

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

lib/liquid/tags/capture.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Capture stores the result of a block into a variable without rendering it inplace.
   #
@@ -16,9 +18,9 @@ module Liquid
     def initialize(tag_name, markup, options)
       super
       if markup =~ Syntax
-        @to = $1
+        @to = Regexp.last_match(1)
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.capture"))
+        raise SyntaxError, options[:locale].t("errors.syntax.capture")
       end
     end
 
@@ -35,5 +37,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('capture'.freeze, Capture)
+  Template.register_tag('capture', Capture)
 end

lib/liquid/tags/case.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Case < Block
     Syntax     = /(#{QuotedFragment})/o
@@ -10,17 +12,15 @@ module Liquid
       @blocks = []
 
       if markup =~ Syntax
-        @left = Expression.parse($1)
+        @left = Expression.parse(Regexp.last_match(1))
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.case".freeze))
+        raise SyntaxError, options[:locale].t("errors.syntax.case")
       end
     end
 
     def parse(tokens)
       body = BlockBody.new
-      while parse_body(body, tokens)
-        body = @blocks.last.attachment
-      end
+      body = @blocks.last.attachment while parse_body(body, tokens)
     end
 
     def nodelist
@@ -29,9 +29,9 @@ module Liquid
 
     def unknown_tag(tag, markup, tokens)
       case tag
-      when 'when'.freeze
+      when 'when'
         record_when_condition(markup)
-      when 'else'.freeze
+      when 'else'
         record_else_condition(markup)
       else
         super
@@ -39,16 +39,14 @@ module Liquid
     end
 
     def render_to_output_buffer(context, output)
-      context.stack do
-        execute_else_block = true
+      execute_else_block = true
 
-        @blocks.each do |block|
-          if block.else?
-            block.attachment.render_to_output_buffer(context, output) if execute_else_block
-          elsif block.evaluate(context)
-            execute_else_block = false
-            block.attachment.render_to_output_buffer(context, output)
-          end
+      @blocks.each do |block|
+        if block.else?
+          block.attachment.render_to_output_buffer(context, output) if execute_else_block
+        elsif block.evaluate(context)
+          execute_else_block = false
+          block.attachment.render_to_output_buffer(context, output)
         end
       end
 
@@ -62,12 +60,12 @@ module Liquid
 
       while markup
         unless markup =~ WhenSyntax
-          raise SyntaxError.new(options[:locale].t("errors.syntax.case_invalid_when".freeze))
+          raise SyntaxError, options[:locale].t("errors.syntax.case_invalid_when")
         end
 
-        markup = $2
+        markup = Regexp.last_match(2)
 
-        block = Condition.new(@left, '=='.freeze, Expression.parse($1))
+        block = Condition.new(@left, '==', Expression.parse(Regexp.last_match(1)))
         block.attach(body)
         @blocks << block
       end
@@ -75,7 +73,7 @@ module Liquid
 
     def record_else_condition(markup)
       unless markup.strip.empty?
-        raise SyntaxError.new(options[:locale].t("errors.syntax.case_invalid_else".freeze))
+        raise SyntaxError, options[:locale].t("errors.syntax.case_invalid_else")
       end
 
       block = ElseCondition.new
@@ -90,5 +88,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('case'.freeze, Case)
+  Template.register_tag('case', Case)
 end

lib/liquid/tags/comment.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Comment < Block
     def render_to_output_buffer(_context, output)
@@ -12,5 +14,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('comment'.freeze, Comment)
+  Template.register_tag('comment', Comment)
 end

lib/liquid/tags/continue.rb

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

lib/liquid/tags/cycle.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Cycle is usually used within a loop to alternate between values, like colors or DOM classes.
   #
@@ -21,38 +23,36 @@ module Liquid
       super
       case markup
       when NamedSyntax
-        @variables = variables_from_string($2)
-        @name = Expression.parse($1)
+        @variables = variables_from_string(Regexp.last_match(2))
+        @name = Expression.parse(Regexp.last_match(1))
       when SimpleSyntax
         @variables = variables_from_string(markup)
         @name = @variables.to_s
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.cycle".freeze))
+        raise SyntaxError, options[:locale].t("errors.syntax.cycle")
       end
     end
 
     def render_to_output_buffer(context, output)
       context.registers[:cycle] ||= {}
 
-      context.stack do
-        key = context.evaluate(@name)
-        iteration = context.registers[:cycle][key].to_i
+      key = context.evaluate(@name)
+      iteration = context.registers[:cycle][key].to_i
 
-        val = context.evaluate(@variables[iteration])
+      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
-
-        iteration += 1
-        iteration  = 0 if iteration >= @variables.size
-        context.registers[:cycle][key] = iteration
+      if val.is_a?(Array)
+        val = val.join
+      elsif !val.is_a?(String)
+        val = val.to_s
       end
 
+      output << val
+
+      iteration += 1
+      iteration  = 0 if iteration >= @variables.size
+      context.registers[:cycle][key] = iteration
+
       output
     end
 
@@ -61,7 +61,7 @@ module Liquid
     def variables_from_string(markup)
       markup.split(',').collect do |var|
         var =~ /\s*(#{QuotedFragment})\s*/o
-        $1 ? Expression.parse($1) : nil
+        Regexp.last_match(1) ? Expression.parse(Regexp.last_match(1)) : nil
       end.compact
     end
 

lib/liquid/tags/decrement.rb

@@ -1,3 +1,5 @@
+# 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
@@ -32,5 +34,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('decrement'.freeze, Decrement)
+  Template.register_tag('decrement', Decrement)
 end

lib/liquid/tags/echo.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Echo outputs an expression
   #
@@ -16,9 +18,9 @@ module Liquid
     end
 
     def render(context)
-      @variable.render_to_output_buffer(context, '')
+      @variable.render_to_output_buffer(context, +'')
     end
   end
 
-  Template.register_tag('echo'.freeze, Echo)
+  Template.register_tag('echo', Echo)
 end

lib/liquid/tags/for.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # "For" iterates over an array or collection.
   # Several useful variables are available to you within the loop.
@@ -66,7 +68,7 @@ module Liquid
     end
 
     def unknown_tag(tag, markup, tokens)
-      return super unless tag == 'else'.freeze
+      return super unless tag == 'else'
       @else_block = BlockBody.new
     end
 
@@ -86,31 +88,31 @@ module Liquid
 
     def lax_parse(markup)
       if markup =~ Syntax
-        @variable_name = $1
-        collection_name = $2
-        @reversed = !!$3
+        @variable_name = Regexp.last_match(1)
+        collection_name = Regexp.last_match(2)
+        @reversed = !!Regexp.last_match(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.new(options[:locale].t("errors.syntax.for".freeze))
+        raise SyntaxError, options[:locale].t("errors.syntax.for")
       end
     end
 
     def strict_parse(markup)
       p = Parser.new(markup)
       @variable_name = p.consume(:id)
-      raise SyntaxError.new(options[:locale].t("errors.syntax.for_invalid_in".freeze)) unless p.id?('in'.freeze)
+      raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_in") unless p.id?('in')
       collection_name = p.expression
       @name = "#{@variable_name}-#{collection_name}"
       @collection_name = Expression.parse(collection_name)
-      @reversed = p.id?('reversed'.freeze)
+      @reversed = p.id?('reversed')
 
       while p.look(:id) && p.look(:colon, 1)
-        unless attribute = p.id?('limit'.freeze) || p.id?('offset'.freeze)
-          raise SyntaxError.new(options[:locale].t("errors.syntax.for_invalid_attribute".freeze))
+        unless attribute = p.id?('limit') || p.id?('offset')
+          raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_attribute")
         end
         p.consume
         set_attribute(attribute, p.expression)
@@ -162,7 +164,7 @@ module Liquid
         for_stack.push(loop_vars)
 
         begin
-          context['forloop'.freeze] = loop_vars
+          context['forloop'] = loop_vars
 
           segment.each do |item|
             context[@variable_name] = item
@@ -170,11 +172,10 @@ module Liquid
             loop_vars.send(:increment!)
 
             # Handle any interrupts if they exist.
-            if context.interrupt?
-              interrupt = context.pop_interrupt
-              break if interrupt.is_a? BreakInterrupt
-              next if interrupt.is_a? ContinueInterrupt
-            end
+            next unless context.interrupt?
+            interrupt = context.pop_interrupt
+            break if interrupt.is_a?(BreakInterrupt)
+            next if interrupt.is_a?(ContinueInterrupt)
           end
         ensure
           for_stack.pop
@@ -186,13 +187,13 @@ module Liquid
 
     def set_attribute(key, expr)
       case key
-      when 'offset'.freeze
-        @from = if expr == 'continue'.freeze
+      when 'offset'
+        @from = if expr == 'continue'
           :continue
         else
           Expression.parse(expr)
         end
-      when 'limit'.freeze
+      when 'limit'
         @limit = Expression.parse(expr)
       end
     end
@@ -212,5 +213,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('for'.freeze, For)
+  Template.register_tag('for', For)
 end

lib/liquid/tags/if.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # If is the conditional block
   #
@@ -19,7 +21,7 @@ module Liquid
     def initialize(tag_name, markup, options)
       super
       @blocks = []
-      push_block('if'.freeze, markup)
+      push_block('if', markup)
     end
 
     def nodelist
@@ -32,7 +34,7 @@ module Liquid
     end
 
     def unknown_tag(tag, markup, tokens)
-      if ['elsif'.freeze, 'else'.freeze].include?(tag)
+      if ['elsif', 'else'].include?(tag)
         push_block(tag, markup)
       else
         super
@@ -40,11 +42,9 @@ module Liquid
     end
 
     def render_to_output_buffer(context, output)
-      context.stack do
-        @blocks.each do |block|
-          if block.evaluate(context)
-            return block.attachment.render_to_output_buffer(context, output)
-          end
+      @blocks.each do |block|
+        if block.evaluate(context)
+          return block.attachment.render_to_output_buffer(context, output)
         end
       end
 
@@ -54,7 +54,7 @@ module Liquid
     private
 
     def push_block(tag, markup)
-      block = if tag == 'else'.freeze
+      block = if tag == 'else'
         ElseCondition.new
       else
         parse_with_selected_parser(markup)
@@ -66,17 +66,17 @@ module Liquid
 
     def lax_parse(markup)
       expressions = markup.scan(ExpressionsAndOperators)
-      raise(SyntaxError.new(options[:locale].t("errors.syntax.if".freeze))) unless expressions.pop =~ Syntax
+      raise SyntaxError, options[:locale].t("errors.syntax.if") unless expressions.pop =~ Syntax
 
-      condition = Condition.new(Expression.parse($1), $2, Expression.parse($3))
+      condition = Condition.new(Expression.parse(Regexp.last_match(1)), Regexp.last_match(2), Expression.parse(Regexp.last_match(3)))
 
       until expressions.empty?
         operator = expressions.pop.to_s.strip
 
-        raise(SyntaxError.new(options[:locale].t("errors.syntax.if".freeze))) unless expressions.pop.to_s =~ Syntax
+        raise SyntaxError, options[:locale].t("errors.syntax.if") unless expressions.pop.to_s =~ Syntax
 
-        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 = 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.send(operator, condition)
         condition = new_condition
       end
@@ -94,7 +94,7 @@ module Liquid
     def parse_binary_comparisons(p)
       condition = parse_comparison(p)
       first_condition = condition
-      while op = (p.id?('and'.freeze) || p.id?('or'.freeze))
+      while op = (p.id?('and') || p.id?('or'))
         child_condition = parse_comparison(p)
         condition.send(op, child_condition)
         condition = child_condition
@@ -119,5 +119,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('if'.freeze, If)
+  Template.register_tag('if', If)
 end

lib/liquid/tags/ifchanged.rb

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

lib/liquid/tags/include.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Include allows templates to relate with other templates
   #
@@ -23,8 +25,8 @@ module Liquid
 
       if markup =~ Syntax
 
-        template_name = $1
-        variable_name = $3
+        template_name = Regexp.last_match(1)
+        variable_name = Regexp.last_match(3)
 
         @variable_name_expr = variable_name ? Expression.parse(variable_name) : nil
         @template_name_expr = Expression.parse(template_name)
@@ -35,7 +37,7 @@ module Liquid
         end
 
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.include".freeze))
+        raise SyntaxError, options[:locale].t("errors.syntax.include")
       end
     end
 
@@ -44,7 +46,7 @@ module Liquid
 
     def render_to_output_buffer(context, output)
       template_name = context.evaluate(@template_name_expr)
-      raise ArgumentError.new(options[:locale].t("errors.argument.include")) unless template_name
+      raise ArgumentError, options[:locale].t("errors.argument.include") unless template_name
 
       partial = PartialCache.load(
         template_name,
@@ -52,7 +54,7 @@ module Liquid
         parse_context: parse_context
       )
 
-      context_variable_name = template_name.split('/'.freeze).last
+      context_variable_name = template_name.split('/').last
 
       variable = if @variable_name_expr
         context.evaluate(@variable_name_expr)
@@ -95,11 +97,11 @@ module Liquid
       def children
         [
           @node.template_name_expr,
-          @node.variable_name_expr
+          @node.variable_name_expr,
         ] + @node.attributes.values
       end
     end
   end
 
-  Template.register_tag('include'.freeze, Include)
+  Template.register_tag('include', Include)
 end

lib/liquid/tags/increment.rb

@@ -1,3 +1,5 @@
+# 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
@@ -29,5 +31,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('increment'.freeze, Increment)
+  Template.register_tag('increment', Increment)
 end

lib/liquid/tags/raw.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Raw < Block
     Syntax = /\A\s*\z/
@@ -10,16 +12,16 @@ module Liquid
     end
 
     def parse(tokens)
-      @body = ''
+      @body = +''
       while token = tokens.shift
         if token =~ FullTokenPossiblyInvalid
-          @body << $1 if $1 != "".freeze
-          return if block_delimiter == $2
+          @body << Regexp.last_match(1) if Regexp.last_match(1) != ""
+          return if block_delimiter == Regexp.last_match(2)
         end
         @body << token unless token.empty?
       end
 
-      raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_never_closed".freeze, block_name: block_name))
+      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed", block_name: block_name)
     end
 
     def render_to_output_buffer(_context, output)
@@ -39,10 +41,10 @@ module Liquid
 
     def ensure_valid_markup(tag_name, markup, parse_context)
       unless markup =~ Syntax
-        raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_unexpected_args".freeze, tag: tag_name))
+        raise SyntaxError, parse_context.locale.t("errors.syntax.tag_unexpected_args", tag: tag_name)
       end
     end
   end
 
-  Template.register_tag('raw'.freeze, Raw)
+  Template.register_tag('raw', Raw)
 end

lib/liquid/tags/render.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Render < Tag
     SYNTAX = /(#{QuotedString})#{QuotedFragment}*/o
@@ -7,9 +9,9 @@ module Liquid
     def initialize(tag_name, markup, options)
       super
 
-      raise SyntaxError.new(options[:locale].t("errors.syntax.render".freeze)) unless markup =~ SYNTAX
+      raise SyntaxError, options[:locale].t("errors.syntax.render") unless markup =~ SYNTAX
 
-      template_name = $1
+      template_name = Regexp.last_match(1)
 
       @template_name_expr = Expression.parse(template_name)
 
@@ -22,7 +24,7 @@ module Liquid
     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.new(options[:locale].t("errors.argument.include")) unless template_name
+      raise ArgumentError, options[:locale].t("errors.argument.include") unless template_name
 
       partial = PartialCache.load(
         template_name,
@@ -50,5 +52,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('render'.freeze, Render)
+  Template.register_tag('render', Render)
 end

lib/liquid/tags/table_row.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class TableRow < Block
     Syntax = /(\w+)\s+in\s+(#{QuotedFragment}+)/o
@@ -7,33 +9,33 @@ module Liquid
     def initialize(tag_name, markup, options)
       super
       if markup =~ Syntax
-        @variable_name = $1
-        @collection_name = Expression.parse($2)
+        @variable_name = Regexp.last_match(1)
+        @collection_name = Expression.parse(Regexp.last_match(2))
         @attributes = {}
         markup.scan(TagAttributes) do |key, value|
           @attributes[key] = Expression.parse(value)
         end
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.table_row".freeze))
+        raise SyntaxError, options[:locale].t("errors.syntax.table_row")
       end
     end
 
     def render_to_output_buffer(context, output)
-      collection = context.evaluate(@collection_name) or return ''.freeze
+      (collection = context.evaluate(@collection_name)) || (return '')
 
-      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
+      from = @attributes.key?('offset') ? context.evaluate(@attributes['offset']).to_i : 0
+      to = @attributes.key?('limit') ? from + context.evaluate(@attributes['limit']).to_i : nil
 
       collection = Utils.slice_collection(collection, from, to)
 
       length = collection.length
 
-      cols = context.evaluate(@attributes['cols'.freeze]).to_i
+      cols = context.evaluate(@attributes['cols']).to_i
 
       output << "<tr class=\"row1\">\n"
       context.stack do
         tablerowloop = Liquid::TablerowloopDrop.new(length, cols)
-        context['tablerowloop'.freeze] = tablerowloop
+        context['tablerowloop'] = tablerowloop
 
         collection.each do |item|
           context[@variable_name] = item
@@ -61,5 +63,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('tablerow'.freeze, TableRow)
+  Template.register_tag('tablerow', TableRow)
 end

lib/liquid/tags/unless.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative 'if'
 
 module Liquid
@@ -7,18 +9,16 @@ module Liquid
   #
   class Unless < If
     def render_to_output_buffer(context, output)
-      context.stack do
-        # 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)
-        end
+      # 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)
+      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)
-          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)
         end
       end
 
@@ -26,5 +26,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('unless'.freeze, Unless)
+  Template.register_tag('unless', Unless)
 end

lib/liquid/template.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   # Templates are central to liquid.
   # Interpretating templates is a two step process. First you compile the
@@ -165,14 +167,14 @@ module Liquid
     #    filters and tags and might be useful to integrate liquid more with its host application
     #
     def render(*args)
-      return ''.freeze if @root.nil?
+      return '' 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
@@ -208,7 +210,7 @@ module Liquid
         # 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 || '')
+          @root.render_to_output_buffer(context, output || +'')
         end
       rescue Liquid::MemoryError => e
         context.handle_error(e)

lib/liquid/tokenizer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   class Tokenizer
     attr_reader :line_number, :for_liquid_tag
@@ -10,7 +12,7 @@ module Liquid
     end
 
     def shift
-      token = @tokens.shift or return
+      (token = @tokens.shift) || return
 
       if @line_number
         @line_number += @for_liquid_tag ? 1 : token.count("\n")
@@ -29,7 +31,7 @@ module Liquid
       tokens = @source.split(TemplateParser)
 
       # removes the rogue empty element at the beginning of the array
-      tokens.shift if tokens[0] && tokens[0].empty?
+      tokens.shift if tokens[0]&.empty?
 
       tokens
     end

lib/liquid/usage.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Liquid
   module Usage
     def self.increment(name)

lib/liquid/utils.rb

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

lib/liquid/variable.rb

@@ -1,3 +1,5 @@
+# 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
@@ -43,11 +45,11 @@ module Liquid
       @filters = []
       return unless markup =~ MarkupWithQuotedFragment
 
-      name_markup = $1
-      filter_markup = $2
+      name_markup = Regexp.last_match(1)
+      filter_markup = Regexp.last_match(2)
       @name = Expression.parse(name_markup)
       if filter_markup =~ FilterMarkupRegex
-        filters = $1.scan(FilterParser)
+        filters = Regexp.last_match(1).scan(FilterParser)
         filters.each do |f|
           next unless f =~ /\w+/
           filtername = Regexp.last_match(0)
@@ -121,7 +123,7 @@ 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

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

lib/liquid/version.rb

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

liquid.gemspec

@@ -1,7 +1,8 @@
 # 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"
 
@@ -26,6 +27,6 @@ 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

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

performance/profile.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'stackprof'
 require_relative 'theme_runner'
 

performance/shopify/comment_form.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CommentForm < Liquid::Block
   Syntax = /(#{Liquid::VariableSignature}+)/
 
@@ -5,10 +7,10 @@ class CommentForm < Liquid::Block
     super
 
     if markup =~ Syntax
-      @variable_name = $1
+      @variable_name = Regexp.last_match(1)
       @attributes = {}
     else
-      raise SyntaxError.new("Syntax Error in 'comment_form' - Valid syntax: comment_form [article]")
+      raise SyntaxError, "Syntax Error in 'comment_form' - Valid syntax: comment_form [article]"
     end
   end
 
@@ -20,8 +22,8 @@ class CommentForm < Liquid::Block
         '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))

performance/shopify/database.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'yaml'
 
 module Database
@@ -16,9 +18,10 @@ module Database
       end
 
       # key the tables by handles, as this is how liquid expects it.
-      db = db.inject({}) do |assigns, (key, values)|
-        assigns[key] = values.inject({}) { |h, v| h[v['handle']] = v; h; }
-        assigns
+      db = db.each_with_object({}) do |(key, values), assigns|
+        assigns[key] = values.each_with_object({}) do |v, h|
+          h[v['handle']] = v
+        end
       end
 
       # Some standard direct accessors so that the specialized templates
@@ -30,8 +33,8 @@ module Database
 
       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
+        'item_count' => db['line_items'].values.inject(0) { |sum, item| sum += item['quantity'] },
+        'items' => db['line_items'].values,
       }
 
       db
@@ -40,6 +43,6 @@ 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

@@ -1,7 +1,9 @@
+# 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

@@ -1,4 +1,6 @@
-$:.unshift __dir__ + '/../../lib'
+# frozen_string_literal: true
+
+$LOAD_PATH.unshift(__dir__ + '/../../lib')
 require_relative '../../lib/liquid'
 
 require_relative 'comment_form'
@@ -9,11 +11,11 @@ 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

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

performance/shopify/paginate.rb

@@ -1,13 +1,15 @@
+# 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 = $1
-      @page_size = if $2
-        $3.to_i
+      @collection_name = Regexp.last_match(1)
+      @page_size = if Regexp.last_match(2)
+        Regexp.last_match(3).to_i
       else
         20
       end
@@ -17,7 +19,7 @@ class Paginate < Liquid::Block
         @attributes[key] = value
       end
     else
-      raise SyntaxError.new("Syntax Error in tag 'paginate' - Valid syntax: paginate [collection] by number")
+      raise SyntaxError, "Syntax Error in tag 'paginate' - Valid syntax: paginate [collection] by number"
     end
   end
 
@@ -25,19 +27,19 @@ class Paginate < Liquid::Block
     @context = context
 
     context.stack do
-      current_page  = context['current_page'].to_i
+      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.new("Cannot paginate array '#{@collection_name}'. Not found.") if collection_size.nil?
+      raise ArgumentError, "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

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

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

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

performance/theme_runner.rb

@@ -1,3 +1,5 @@
+# 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.
@@ -31,7 +33,7 @@ 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

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

test/integration/blank_test.rb

@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class FoobarTag < Liquid::Tag
-  def render_to_output_buffer(context, output)
+  def render_to_output_buffer(_context, output)
     output << ' '
     output
   end

test/integration/block_test.rb

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

test/integration/capture_test.rb

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

test/integration/context_test.rb

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

test/integration/document_test.rb

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

test/integration/drop_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ContextDrop < Liquid::Drop
@@ -31,7 +33,7 @@ class ProductDrop < Liquid::Drop
 
   class CatchallDrop < Liquid::Drop
     def liquid_method_missing(method)
-      'catchall_method: ' << method.to_s
+      "catchall_method: #{method}"
     end
   end
 
@@ -48,7 +50,7 @@ class ProductDrop < Liquid::Drop
   end
 
   def user_input
-    "foo".taint
+    (+"foo").taint
   end
 
   protected
@@ -201,9 +203,9 @@ class DropsTest < Minitest::Test
   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])
+    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
@@ -241,7 +243,7 @@ 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)
@@ -250,7 +252,7 @@ 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)
@@ -270,4 +272,11 @@ 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

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ErrorHandlingTest < Minitest::Test
@@ -83,15 +85,14 @@ class ErrorHandlingTest < Minitest::Test
 
   def test_with_line_numbers_adds_numbers_to_parser_errors
     err = assert_raises(SyntaxError) do
-      Liquid::Template.parse(%q(
+      Liquid::Template.parse('
           foobar
 
           {% "cat" | foobar %}
 
           bla
-        ),
-        line_numbers: true
-      )
+        ',
+        line_numbers: true)
     end
 
     assert_match(/Liquid syntax error \(line 4\)/, err.message)
@@ -99,15 +100,14 @@ 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(%q(
+      Liquid::Template.parse('
           foobar
 
           {%- "cat" | foobar -%}
 
           bla
-        ),
-        line_numbers: true
-      )
+        ',
+        line_numbers: true)
     end
 
     assert_match(/Liquid syntax error \(line 4\)/, err.message)
@@ -122,8 +122,7 @@ 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)
@@ -139,8 +138,7 @@ 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
@@ -157,8 +155,7 @@ class ErrorHandlingTest < Minitest::Test
 
           bla
                 ',
-        line_numbers: true
-      )
+        line_numbers: true)
     end
 
     assert_equal "Liquid syntax error (line 5): Unknown tag 'foo'", err.message
@@ -205,7 +202,7 @@ 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)
@@ -217,7 +214,7 @@ class ErrorHandlingTest < Minitest::Test
     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)
@@ -239,7 +236,7 @@ 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

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

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

test/integration/output_test.rb

@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 module FunnyFilter
-  def make_funny(input)
+  def make_funny(_input)
     'LOL'
   end
 
@@ -32,7 +34,7 @@ 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

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

test/integration/render_profiling_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class RenderProfilingTest < Minitest::Test
@@ -128,7 +130,7 @@ class RenderProfilingTest < Minitest::Test
     t.render!
 
     timing_count = 0
-    t.profiler.each do |timing|
+    t.profiler.each do |_timing|
       timing_count += 1
     end
 
@@ -145,7 +147,7 @@ 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

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

test/integration/standard_filter_test.rb

@@ -1,4 +1,5 @@
 # encoding: utf-8
+# frozen_string_literal: true
 
 require 'test_helper'
 
@@ -17,7 +18,7 @@ class TestThing
     "woot: #{@foo}"
   end
 
-  def [](whatever)
+  def [](_whatever)
     to_s
   end
 
@@ -37,7 +38,7 @@ 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
 
@@ -208,14 +209,14 @@ 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
@@ -236,14 +237,14 @@ 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
@@ -256,7 +257,7 @@ class StandardFiltersTest < Minitest::Test
       { "fake" => "t" },
       { "key" => "a" },
       { "key" => "b" },
-      { "key" => "c" }
+      { "key" => "c" },
     ]
     expectation = [
       { "key" => "a" },
@@ -265,7 +266,7 @@ 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"])
@@ -279,7 +280,7 @@ class StandardFiltersTest < Minitest::Test
     foo = [
       [1],
       [2],
-      [3]
+      [3],
     ]
 
     assert_raises Liquid::ArgumentError do
@@ -295,7 +296,7 @@ class StandardFiltersTest < Minitest::Test
     foo = [
       [1],
       [2],
-      [3]
+      [3],
     ]
 
     assert_raises Liquid::ArgumentError do
@@ -304,7 +305,7 @@ 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
@@ -330,7 +331,7 @@ class StandardFiltersTest < Minitest::Test
     foo = [
       [1],
       [2],
-      [3]
+      [3],
     ]
 
     assert_raises Liquid::ArgumentError do
@@ -346,7 +347,7 @@ class StandardFiltersTest < Minitest::Test
     foo = [
       [1],
       [2],
-      [3]
+      [3],
     ]
 
     assert_raises Liquid::ArgumentError do
@@ -380,7 +381,7 @@ 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
@@ -397,7 +398,7 @@ 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
@@ -405,10 +406,10 @@ class StandardFiltersTest < Minitest::Test
   def test_map_over_drops_returning_procs
     drops = [
       {
-        "proc" => ->{ "foo" },
+        "proc" => -> { "foo" },
       },
       {
-        "proc" => ->{ "bar" },
+        "proc" => -> { "bar" },
       },
     ]
     templ = '{{ drops | map: "proc" }}'
@@ -423,7 +424,7 @@ class StandardFiltersTest < Minitest::Test
     foo = [
       [1],
       [2],
-      [3]
+      [3],
     ]
 
     assert_raises Liquid::ArgumentError do
@@ -435,7 +436,7 @@ class StandardFiltersTest < Minitest::Test
     foo = [
       [1],
       [2],
-      [3]
+      [3],
     ]
     assert_raises Liquid::ArgumentError do
       @filters.map(foo, nil)
@@ -697,12 +698,12 @@ 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)
@@ -714,12 +715,12 @@ 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)
@@ -740,7 +741,7 @@ 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")
@@ -758,7 +759,7 @@ 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

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

test/integration/tags/continue_tag_test.rb

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

test/integration/tags/echo_test.rb

@@ -1,10 +1,12 @@
+# 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' })
+    assert_template_result('BAR', <<~LIQUID, 'variable-name' => 'bar')
       {%- echo variable-name | upcase -%}
     LIQUID
   end

test/integration/tags/for_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ThingWithValue < Liquid::Drop
@@ -23,16 +25,16 @@ 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
 

test/integration/tags/if_else_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class IfElseTagTest < Minitest::Test
@@ -132,7 +134,7 @@ class IfElseTagTest < Minitest::Test
   end
 
   def test_syntax_error_no_variable
-    assert_raises(SyntaxError){ assert_template_result('', '{% if jerry == 1 %}') }
+    assert_raises(SyntaxError) { assert_template_result('', '{% if jerry == 1 %}') }
   end
 
   def test_syntax_error_no_expression

test/integration/tags/include_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class TestFileSystem
@@ -40,14 +42,14 @@ class TestFileSystem
 end
 
 class OtherFileSystem
-  def read_template_file(template_path)
+  def read_template_file(_template_path)
     'from OtherFileSystem'
   end
 end
 
 class CountingFileSystem
   attr_reader :count
-  def read_template_file(template_path)
+  def read_template_file(_template_path)
     @count ||= 0
     @count += 1
     'from CountingFileSystem'
@@ -59,14 +61,14 @@ class CustomInclude < Liquid::Tag
 
   def initialize(tag_name, markup, tokens)
     markup =~ Syntax
-    @template_name = $1
+    @template_name = Regexp.last_match(1)
     super
   end
 
   def parse(tokens)
   end
 
-  def render_to_output_buffer(context, output)
+  def render_to_output_buffer(_context, output)
     output << @template_name[1..-2]
     output
   end
@@ -86,7 +88,7 @@ class IncludeTagTest < Minitest::Test
 
   def test_include_tag_with
     assert_template_result "Product: Draft 151cm ",
-      "{% include 'product' with products[0] %}", "products" => [ { 'title' => 'Draft 151cm' }, { 'title' => 'Element 155cm' } ]
+      "{% include 'product' with products[0] %}", "products" => [{ 'title' => 'Draft 151cm' }, { 'title' => 'Element 155cm' }]
   end
 
   def test_include_tag_with_default_name
@@ -96,7 +98,7 @@ class IncludeTagTest < Minitest::Test
 
   def test_include_tag_for
     assert_template_result "Product: Draft 151cm Product: Element 155cm ",
-      "{% include 'product' for products %}", "products" => [ { 'title' => 'Draft 151cm' }, { 'title' => 'Element 155cm' } ]
+      "{% include 'product' for products %}", "products" => [{ 'title' => 'Draft 151cm' }, { 'title' => 'Element 155cm' }]
   end
 
   def test_include_tag_with_local_variables
@@ -134,7 +136,7 @@ class IncludeTagTest < Minitest::Test
 
   def test_recursively_included_template_does_not_produce_endless_loop
     infinite_file_system = Class.new do
-      def read_template_file(template_path)
+      def read_template_file(_template_path)
         "-{% include 'loop' %}"
       end
     end

test/integration/tags/increment_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class IncrementTagTest < Minitest::Test
@@ -13,11 +15,11 @@ class IncrementTagTest < Minitest::Test
   end
 
   def test_dec
-    assert_template_result('9', '{%decrement port %}', { 'port' => 10 })
+    assert_template_result('9', '{%decrement port %}', 'port' => 10)
     assert_template_result('-1 -2', '{%decrement port %} {%decrement port%}', {})
     assert_template_result('1 5 2 2 5',
       '{%increment port %} {%increment starboard%} ' \
       '{%increment port %} {%decrement port%} ' \
-      '{%decrement starboard %}', { 'port' => 1, 'starboard' => 5 })
+      '{%decrement starboard %}', 'port' => 1, 'starboard' => 5)
   end
 end

test/integration/tags/liquid_tag_test.rb

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

test/integration/tags/raw_tag_test.rb

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