Add support for iterating ranges with float boundaries.

The meaning I gave is to start at the lower bound and step by one. This has the advantage of having (n..m) and ((n.to_f)..(m.to_f)) behave the same. Another thing we could do that have this same property is to cast bounds to integer. This would do the right thing if there is a floating point rounding error, but I feel it is more surprising for cases such as (1.5..8). Note that it is not possible to create ranges with floating point boundaries directly in Liquid at the moment. However, since there is no distinction between Ruby and Liquid ranges, a drop can introduce such a value by returning it.
2026-01-02 00:05:42 +03:00 · 2017-08-09 12:13:00 -04:00
135 changed files with 954 additions and 4089 deletions
--- a/.github/probots.yml
+++ b/.github/probots.yml
@@ -1,2 +0,0 @@
-enabled:
-  - cla
--- a/.gitignore
+++ b/.gitignore
@@ -7,4 +7,3 @@ pkg
 .ruby-version
 Gemfile.lock
 .bundle
-.byebug_history
--- a/.rubocop-https---shopify-github-io-ruby-style-guide-rubocop-yml
+++ b/.rubocop-https---shopify-github-io-ruby-style-guide-rubocop-yml
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,17 +1,125 @@
-inherit_from:
-  - 'https://shopify.github.io/ruby-style-guide/rubocop.yml'
-  - .rubocop_todo.yml
-
-require: rubocop-performance
-
-Performance:
-  Enabled: true
+inherit_from: ./.rubocop_todo.yml

 AllCops:
-  TargetRubyVersion: 2.4
  Exclude:
-    - 'vendor/bundle/**/*'
+    - 'performance/shopify/*'
+    - 'pkg/**'

-Naming/MethodName:
+Metrics/BlockNesting:
+  Max: 3
  Exclude:
-    - 'example/server/liquid_servlet.rb'
+    - 'lib/liquid/block_body.rb'
+
+Metrics/ModuleLength:
+  Enabled: false
+
+Metrics/ClassLength:
+  Enabled: false
+
+Lint/AssignmentInCondition:
+  Enabled: false
+
+Lint/AmbiguousOperator:
+  Enabled: false
+
+Lint/AmbiguousRegexpLiteral:
+  Enabled: false
+
+Lint/ParenthesesAsGroupedExpression:
+  Enabled: false
+
+Lint/UnusedBlockArgument:
+  Enabled: false
+
+Lint/EndAlignment:
+  AlignWith: variable
+
+Lint/UnusedMethodArgument:
+  Enabled: false
+
+Style/SingleLineBlockParams:
+  Enabled: false
+
+Style/DoubleNegation:
+  Enabled: false
+
+Style/StringLiteralsInInterpolation:
+  Enabled: false
+
+Style/AndOr:
+  Enabled: false
+
+Style/SignalException:
+  Enabled: false
+
+Style/StringLiterals:
+  Enabled: false
+
+Style/BracesAroundHashParameters:
+  Enabled: false
+
+Style/NumericLiterals:
+  Enabled: false
+
+Style/SpaceInsideBrackets:
+  Enabled: false
+
+Style/SpaceBeforeBlockBraces:
+  Enabled: false
+
+Style/Documentation:
+  Enabled: false
+
+Style/ClassAndModuleChildren:
+  Enabled: false
+
+Style/TrailingComma:
+  Enabled: false
+
+Style/IndentHash:
+  EnforcedStyle: consistent
+
+Style/FormatString:
+  Enabled: false
+
+Style/AlignParameters:
+  EnforcedStyle: with_fixed_indentation
+
+Style/MultilineOperationIndentation:
+  EnforcedStyle: indented
+
+Style/IfUnlessModifier:
+  Enabled: false
+
+Style/RaiseArgs:
+  Enabled: false
+
+Style/DeprecatedHashMethods:
+  Enabled: false
+
+Style/RegexpLiteral:
+  Enabled: false
+
+Style/SymbolLiteral:
+  Enabled: false
+
+Performance/Count:
+  Enabled: false
+
+Style/ConstantName:
+  Enabled: false
+
+Style/CaseIndentation:
+  Enabled: false
+
+Style/ClassVars:
+  Enabled: false
+
+Style/PerlBackrefs:
+  Enabled: false
+
+Style/TrivialAccessors:
+  AllowPredicates: true
+
+Style/WordArray:
+  Enabled: false
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -1,48 +1,72 @@
-# This configuration was generated by
-# `rubocop --auto-gen-config`
-# on 2019-09-11 06:34:25 +1000 using RuboCop version 0.74.0.
+# This configuration was generated by `rubocop --auto-gen-config`
+# on 2015-06-08 18:16:16 +0000 using RuboCop version 0.32.0.
 # 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: 2
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle.
-# SupportedStyles: runtime_error, standard_error
-Lint/InheritException:
-  Exclude:
-    - 'lib/liquid/interrupts.rb'
+# Offense count: 5
+Lint/NestedMethodDefinition:
+  Enabled: false

-# Offense count: 98
-# Cop supports --auto-correct.
-# Configuration parameters: AutoCorrect, AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
-# URISchemes: http, https
+# Offense count: 53
+Metrics/AbcSize:
+  Max: 58
+
+# Offense count: 12
+Metrics/CyclomaticComplexity:
+  Max: 15
+
+# Offense count: 553
+# Configuration parameters: AllowURI, URISchemes.
 Metrics/LineLength:
  Max: 294

-# Offense count: 44
-Naming/ConstantName:
-  Exclude:
-    - 'lib/liquid.rb'
-    - 'lib/liquid/block_body.rb'
-    - 'lib/liquid/tags/assign.rb'
-    - 'lib/liquid/tags/capture.rb'
-    - 'lib/liquid/tags/case.rb'
-    - 'lib/liquid/tags/cycle.rb'
-    - 'lib/liquid/tags/for.rb'
-    - 'lib/liquid/tags/if.rb'
-    - 'lib/liquid/tags/include.rb'
-    - 'lib/liquid/tags/raw.rb'
-    - 'lib/liquid/tags/table_row.rb'
-    - 'lib/liquid/variable.rb'
-    - 'performance/shopify/comment_form.rb'
-    - 'performance/shopify/paginate.rb'
-    - 'test/integration/tags/include_tag_test.rb'
+# Offense count: 77
+# Configuration parameters: CountComments.
+Metrics/MethodLength:
+  Max: 46

-# Offense count: 5
-Style/ClassVars:
-  Exclude:
-    - 'lib/liquid/condition.rb'
-    - 'lib/liquid/strainer.rb'
-    - 'lib/liquid/template.rb'
+# Offense count: 6
+Metrics/PerceivedComplexity:
+  Max: 13
+
+# Offense count: 1
+Style/AccessorMethodName:
+  Enabled: false
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Style/ClosingParenthesisIndentation:
+  Enabled: false
+
+# Offense count: 3
+# Configuration parameters: MinBodyLength.
+Style/GuardClause:
+  Enabled: false
+
+# Offense count: 4
+# Configuration parameters: EnforcedStyle, SupportedStyles.
+Style/MethodName:
+  Enabled: false
+
+# Offense count: 1
+Style/MultilineBlockChain:
+  Enabled: false
+
+# Offense count: 2
+# Configuration parameters: EnforcedStyle, MinBodyLength, SupportedStyles.
+Style/Next:
+  Enabled: false
+
+# Offense count: 7
+# Cop supports --auto-correct.
+# Configuration parameters: AllowAsExpressionSeparator.
+Style/Semicolon:
+  Enabled: false
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: MaxLineLength.
+Style/WhileUntilModifier:
+  Enabled: false
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,26 +1,29 @@
 language: ruby
-cache: bundler

 rvm:
-  - 2.4
-  - 2.5
-  - &latest_ruby 2.6
-  - 2.7
+  - 2.1
+  - 2.2
+  - 2.3.3
  - ruby-head
+  - jruby-head
+#  - rbx-2
+
+sudo: false
+
+addons:
+  apt:
+    packages:
+    - libgmp3-dev

 matrix:
-  include:
-    - rvm: *latest_ruby
-      script: bundle exec rake memory_profile:run
-      name: Profiling Memory Usage
  allow_failures:
-    - rvm: ruby-head
+    - rvm: jruby-head

-branches:
-  only:
-    - master
-    - gh-pages
-    - /.*-stable/
+install:
+  - gem install rainbow -v 2.2.1
+  - bundle install
+
+script: "bundle exec rake"

 notifications:
  disable: true
--- a/20
+++ b/20
@@ -1,27 +1,17 @@
-# frozen_string_literal: true
-
 source 'https://rubygems.org'
-git_source(:github) do |repo_name|
-  "https://github.com/#{repo_name}.git"
-end

 gemspec

+gem 'stackprof', platforms: :mri
+
 group :benchmark, :test do
  gem 'benchmark-ips'
-  gem 'memory_profiler'
-  gem 'terminal-table'
-
-  install_if -> { RUBY_PLATFORM !~ /mingw|mswin|java/ && RUBY_ENGINE != 'truffleruby' } do
-    gem 'stackprof'
-  end
 end

 group :test do
-  gem 'rubocop', '~> 0.74.0', require: false
-  gem 'rubocop-performance', require: false
+  gem 'rubocop', '0.34.2'

-  platform :mri, :truffleruby do
-    gem 'liquid-c', github: 'Shopify/liquid-c', ref: 'master'
+  platform :mri do
+    gem 'liquid-c', github: 'Shopify/liquid-c', ref: 'bd53db95de3d44d631e7c5a267c3d934e66107dd'
  end
 end
--- a/History.md
+++ b/History.md
@@ -1,58 +1,5 @@
 # Liquid Change Log

-## 4.0.3 / 2019-03-12
-
-### Fixed
-* Fix break and continue tags inside included templates in loops (#1072) [Justin Li]
-
-## 4.0.2 / 2019-03-08
-
-### Changed
-* Add `where` filter (#1026) [Samuel Doiron]
-* Add `ParseTreeVisitor` to iterate the Liquid AST (#1025) [Stephen Paul Weber]
-* Improve `strip_html` performance (#1032) [printercu]
-
-### Fixed
-* Add error checking for invalid combinations of inputs to sort, sort_natural, where, uniq, map, compact filters (#1059) [Garland Zhang]
-* Validate the character encoding in url_decode (#1070) [Clayton Smith]
-
-## 4.0.1 / 2018-10-09
-
-### Changed
-* Add benchmark group in Gemfile (#855) [Jerry Liu]
-* Allow benchmarks to benchmark render by itself (#851) [Jerry Liu]
-* Avoid calling `line_number` on String node when rescuing a render error. (#860) [Dylan Thacker-Smith]
-* Avoid duck typing to detect whether to call render on a node. [Dylan Thacker-Smith]
-* Clarify spelling of `reversed` on `for` block tag (#843) [Mark Crossfield]
-* Replace recursion with loop to avoid potential stack overflow from malicious input (#891, #892) [Dylan Thacker-Smith]
-* Limit block tag nesting to 100 (#894) [Dylan Thacker-Smith]
-* Replace `assert_equal nil` with `assert_nil` (#895) [Dylan Thacker-Smith]
-* Remove Spy Gem (#896) [Dylan Thacker-Smith]
-* Add `collection_name` and `variable_name` reader to `For` block (#909)
-* Symbols render as strings (#920) [Justin Li]
-* Remove default value from Hash objects (#932) [Maxime Bedard]
-* Remove one level of nesting (#944) [Dylan Thacker-Smith]
-* Update Rubocop version (#952) [Justin Li]
-* Add `at_least` and `at_most` filters (#954, #958) [Nithin Bekal]
-* Add a regression test for a liquid-c trim mode bug (#972) [Dylan Thacker-Smith]
-* Use https rather than git protocol to fetch liquid-c [Dylan Thacker-Smith]
-* Add tests against Ruby 2.4 (#963) and 2.5 (#981)
-* Replace RegExp literals with constants (#988) [Ashwin Maroli]
-* Replace unnecessary `#each_with_index` with `#each` (#992) [Ashwin Maroli]
-* Improve the unexpected end delimiter message for block tags. (#1003) [Dylan Thacker-Smith]
-* Refactor and optimize rendering (#1005) [Christopher Aue]
-* Add installation instruction (#1006) [Ben Gift]
-* Remove Circle CI (#1010)
-* Rename deprecated `BigDecimal.new` to `BigDecimal` (#1024) [Koichi ITO]
-* Rename deprecated Rubocop name (#1027) [Justin Li]
-
-### Fixed
-* Handle `join` filter on non String joiners (#857) [Richard Monette]
-* Fix duplicate inclusion condition logic error of `Liquid::Strainer.add_filter` method (#861)
-* Fix `escape`, `url_encode`, `url_decode` not handling non-string values (#898) [Thierry Joyal]
-* Fix raise when variable is defined but nil when using `strict_variables` [Pascal Betz]
-* Fix `sort` and `sort_natural` to handle arrays with nils (#930) [Eric Chan]
-
 ## 4.0.0 / 2016-12-14 / branch "4-0-stable"

 ### Changed
--- a/README.md
+++ b/README.md
@@ -42,8 +42,6 @@ Liquid is a template engine which was written with very specific requirements:

 ## How to use Liquid

-Install Liquid by adding `gem 'liquid'` to your gemfile.
-
 Liquid supports a very simple API based around the Liquid::Template class.
 For standard use you can just pass it the content of a file and call render with a parameters hash.

@@ -106,9 +104,3 @@ template = Liquid::Template.parse("{{x}} {{y}}")
 template.render!({ 'x' => 1}, { strict_variables: true })
 #=> Liquid::UndefinedVariable: Liquid error: undefined variable y
 ```
-
-### Usage tracking
-
-To help track usages of a feature or code path in production, we have released opt-in usage tracking. To enable this, we provide an empty `Liquid:: Usage.increment` method which you can customize to your needs. The feature is well suited to https://github.com/Shopify/statsd-instrument. However, the choice of implementation is up to you.
-
-Once you have enabled usage tracking, we recommend reporting any events through Github Issues that your system may be logging. It is highly likely this event has been added to consider deprecating or improving code specific to this event, so please raise any concerns.
--- a/33
+++ b/33
@@ -1,33 +1,29 @@
-# frozen_string_literal: true
-
 require 'rake'
 require 'rake/testtask'
-$LOAD_PATH.unshift(File.expand_path("../lib", __FILE__))
+$LOAD_PATH.unshift File.expand_path("../lib", __FILE__)
 require "liquid/version"

-task(default: [:test, :rubocop])
+task default: [:rubocop, :test]

-desc('run test suite with default parser')
+desc 'run test suite with default parser'
 Rake::TestTask.new(:base_test) do |t|
  t.libs << '.' << 'lib' << 'test'
  t.test_files = FileList['test/{integration,unit}/**/*_test.rb']
  t.verbose = false
 end

-desc('run test suite with warn error mode')
+desc 'run test suite with warn error mode'
 task :warn_test do
  ENV['LIQUID_PARSER_MODE'] = 'warn'
  Rake::Task['base_test'].invoke
 end

 task :rubocop do
-  if RUBY_ENGINE == 'ruby'
-    require 'rubocop/rake_task'
-    RuboCop::RakeTask.new
-  end
+  require 'rubocop/rake_task'
+  RuboCop::RakeTask.new
 end

-desc('runs test suite with both strict and lax parsers')
+desc 'runs test suite with both strict and lax parsers'
 task :test do
  ENV['LIQUID_PARSER_MODE'] = 'lax'
  Rake::Task['base_test'].invoke
@@ -36,8 +32,8 @@ task :test do
  Rake::Task['base_test'].reenable
  Rake::Task['base_test'].invoke

-  if RUBY_ENGINE == 'ruby' || RUBY_ENGINE == 'truffleruby'
-    ENV['LIQUID_C'] = '1'
+  if RUBY_ENGINE == 'ruby'
+    ENV['LIQUID-C'] = '1'

    ENV['LIQUID_PARSER_MODE'] = 'lax'
    Rake::Task['base_test'].reenable
@@ -49,7 +45,7 @@ task :test do
  end
 end

-task(gem: :build)
+task gem: :build
 task :build do
  system "gem build liquid.gemspec"
 end
@@ -89,14 +85,7 @@ namespace :profile do
  end
 end

-namespace :memory_profile do
-  desc "Run memory profiler"
-  task :run do
-    ruby "./performance/memory_profile.rb"
-  end
-end
-
-desc("Run example")
+desc "Run example"
 task :example do
  ruby "-w -d -Ilib example/server/server.rb"
 end
--- a/circle.yml
+++ b/circle.yml
@@ -0,0 +1,3 @@
+machine:
+  ruby:
+    version: ruby-2.1
--- a/example/server/example_servlet.rb
+++ b/example/server/example_servlet.rb
@@ -1,8 +1,6 @@
-# frozen_string_literal: true
-
 module ProductsFilter
  def price(integer)
-    format("$%.2d USD", integer / 100.0)
+    sprintf("$%.2d USD", integer / 100.0)
  end

  def prettyprint(text)
--- a/example/server/liquid_servlet.rb
+++ b/example/server/liquid_servlet.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 class LiquidServlet < WEBrick::HTTPServlet::AbstractServlet
  def do_GET(req, res)
    handle(:get, req, res)
@@ -11,12 +9,12 @@ class LiquidServlet < WEBrick::HTTPServlet::AbstractServlet

  private

-  def handle(_type, req, res)
+  def handle(type, req, res)
    @request = req
    @response = res

    @request.path_info =~ /(\w+)\z/
-    @action = Regexp.last_match(1) || 'index'
+    @action = $1 || 'index'
    @assigns = send(@action) if respond_to?(@action)

    @response['Content-Type'] = "text/html"
--- a/example/server/server.rb
+++ b/example/server/server.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'webrick'
 require 'rexml/document'

@@ -10,5 +8,5 @@ require_relative 'example_servlet'
 # Setup webrick
 server = WEBrick::HTTPServer.new(Port: ARGV[1] || 3000)
 server.mount('/', Servlet)
-trap("INT") { server.shutdown }
+trap("INT"){ server.shutdown }
 server.start
--- a/lib/liquid.rb
+++ b/lib/liquid.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 # Copyright (c) 2005 Tobias Luetke
 #
 # Permission is hereby granted, free of charge, to any person obtaining
@@ -23,10 +21,10 @@

 module Liquid
  FilterSeparator             = /\|/
-  ArgumentSeparator           = ','
-  FilterArgumentSeparator     = ':'
-  VariableAttributeSeparator  = '.'
-  WhitespaceControl           = '-'
+  ArgumentSeparator           = ','.freeze
+  FilterArgumentSeparator     = ':'.freeze
+  VariableAttributeSeparator  = '.'.freeze
+  WhitespaceControl           = '-'.freeze
  TagStart                    = /\{\%/
  TagEnd                      = /\%\}/
  VariableSignature           = /\(?[\w\-\.\[\]]\)?/
@@ -47,7 +45,6 @@ module Liquid
 end

 require "liquid/version"
-require 'liquid/parse_tree_visitor'
 require 'liquid/lexer'
 require 'liquid/parser'
 require 'liquid/i18n'
@@ -76,9 +73,6 @@ require 'liquid/condition'
 require 'liquid/utils'
 require 'liquid/tokenizer'
 require 'liquid/parse_context'
-require 'liquid/partial_cache'
-require 'liquid/usage'
-require 'liquid/static_registers'

 # Load all the tags of the standard library
 #
--- a/lib/liquid/block.rb
+++ b/lib/liquid/block.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  class Block < Tag
    MAX_DEPTH = 100
@@ -15,7 +13,6 @@ module Liquid
      end
    end

-    # For backwards compatibility
    def render(context)
      @body.render(context)
    end
@@ -29,16 +26,16 @@ module Liquid
    end

    def unknown_tag(tag, _params, _tokens)
-      if tag == 'else'
-        raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_else",
-          block_name: block_name)
-      elsif tag.start_with?('end')
-        raise SyntaxError, parse_context.locale.t("errors.syntax.invalid_delimiter",
-          tag: tag,
+      case tag
+      when 'else'.freeze
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unexpected_else".freeze,
+          block_name: block_name))
+      when 'end'.freeze
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.invalid_delimiter".freeze,
          block_name: block_name,
-          block_delimiter: block_delimiter)
+          block_delimiter: block_delimiter))
      else
-        raise SyntaxError, parse_context.locale.t("errors.syntax.unknown_tag", tag: tag)
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unknown_tag".freeze, tag: tag))
      end
    end

@@ -54,7 +51,7 @@ module Liquid

    def parse_body(body, tokens)
      if parse_context.depth >= MAX_DEPTH
-        raise StackLevelError, "Nesting too deep"
+        raise StackLevelError, "Nesting too deep".freeze
      end
      parse_context.depth += 1
      begin
@@ -63,7 +60,7 @@ module Liquid

          return false if end_tag_name == block_delimiter
          unless end_tag_name
-            raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed", block_name: block_name)
+            raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_never_closed".freeze, block_name: block_name))
          end

          # this tag is not registered with the system
--- a/lib/liquid/block_body.rb
+++ b/lib/liquid/block_body.rb
@@ -1,13 +1,9 @@
-# frozen_string_literal: true
-
 module Liquid
  class BlockBody
-    LiquidTagToken = /\A\s*(\w+)\s*(.*?)\z/o
-    FullToken = /\A#{TagStart}#{WhitespaceControl}?(\s*)(\w+)(\s*)(.*?)#{WhitespaceControl}?#{TagEnd}\z/om
+    FullToken = /\A#{TagStart}#{WhitespaceControl}?\s*(\w+)\s*(.*?)#{WhitespaceControl}?#{TagEnd}\z/om
    ContentOfVariable = /\A#{VariableStart}#{WhitespaceControl}?(.*?)#{WhitespaceControl}?#{VariableEnd}\z/om
-    WhitespaceOrNothing = /\A\s*\z/
-    TAGSTART = "{%"
-    VARSTART = "{{"
+    TAGSTART = "{%".freeze
+    VARSTART = "{{".freeze

    attr_reader :nodelist

@@ -16,83 +12,41 @@ module Liquid
      @blank = true
    end

-    def parse(tokenizer, parse_context, &block)
+    def parse(tokenizer, parse_context)
      parse_context.line_number = tokenizer.line_number
-
-      if tokenizer.for_liquid_tag
-        parse_for_liquid_tag(tokenizer, parse_context, &block)
-      else
-        parse_for_document(tokenizer, parse_context, &block)
-      end
-    end
-
-    private def parse_for_liquid_tag(tokenizer, parse_context)
-      while (token = tokenizer.shift)
-        unless token.empty? || token =~ WhitespaceOrNothing
-          unless token =~ LiquidTagToken
-            # line isn't empty but didn't match tag syntax, yield and let the
-            # caller raise a syntax error
-            return yield token, token
+      while token = tokenizer.shift
+        unless token.empty?
+          case
+          when token.start_with?(TAGSTART)
+            whitespace_handler(token, parse_context)
+            if token =~ FullToken
+              tag_name = $1
+              markup = $2
+              # fetch the tag from registered blocks
+              if tag = registered_tags[tag_name]
+                new_tag = tag.parse(tag_name, markup, tokenizer, parse_context)
+                @blank &&= new_tag.blank?
+                @nodelist << new_tag
+              else
+                # end parsing if we reach an unknown tag and let the caller decide
+                # determine how to proceed
+                return yield tag_name, markup
+              end
+            else
+              raise_missing_tag_terminator(token, parse_context)
+            end
+          when token.start_with?(VARSTART)
+            whitespace_handler(token, parse_context)
+            @nodelist << create_variable(token, parse_context)
+            @blank = false
+          else
+            if parse_context.trim_whitespace
+              token.lstrip!
+            end
+            parse_context.trim_whitespace = false
+            @nodelist << token
+            @blank &&= !!(token =~ /\A\s*\z/)
          end
-          tag_name = Regexp.last_match(1)
-          markup = Regexp.last_match(2)
-          unless (tag = registered_tags[tag_name])
-            # end parsing if we reach an unknown tag and let the caller decide
-            # determine how to proceed
-            return yield tag_name, markup
-          end
-          new_tag = tag.parse(tag_name, markup, tokenizer, parse_context)
-          @blank &&= new_tag.blank?
-          @nodelist << new_tag
-        end
-        parse_context.line_number = tokenizer.line_number
-      end
-
-      yield nil, nil
-    end
-
-    private def parse_for_document(tokenizer, parse_context, &block)
-      while (token = tokenizer.shift)
-        next if token.empty?
-        case
-        when token.start_with?(TAGSTART)
-          whitespace_handler(token, parse_context)
-          unless token =~ FullToken
-            raise_missing_tag_terminator(token, parse_context)
-          end
-          tag_name = Regexp.last_match(2)
-          markup = Regexp.last_match(4)
-
-          if parse_context.line_number
-            # newlines inside the tag should increase the line number,
-            # particularly important for multiline {% liquid %} tags
-            parse_context.line_number += Regexp.last_match(1).count("\n") + Regexp.last_match(3).count("\n")
-          end
-
-          if tag_name == 'liquid'
-            liquid_tag_tokenizer = Tokenizer.new(markup, line_number: parse_context.line_number, for_liquid_tag: true)
-            next parse_for_liquid_tag(liquid_tag_tokenizer, parse_context, &block)
-          end
-
-          unless (tag = registered_tags[tag_name])
-            # end parsing if we reach an unknown tag and let the caller decide
-            # determine how to proceed
-            return yield tag_name, markup
-          end
-          new_tag = tag.parse(tag_name, markup, tokenizer, parse_context)
-          @blank &&= new_tag.blank?
-          @nodelist << new_tag
-        when token.start_with?(VARSTART)
-          whitespace_handler(token, parse_context)
-          @nodelist << create_variable(token, parse_context)
-          @blank = false
-        else
-          if parse_context.trim_whitespace
-            token.lstrip!
-          end
-          parse_context.trim_whitespace = false
-          @nodelist << token
-          @blank &&= !!(token =~ WhitespaceOrNothing)
        end
        parse_context.line_number = tokenizer.line_number
      end
@@ -103,7 +57,7 @@ module Liquid
    def whitespace_handler(token, parse_context)
      if token[2] == WhitespaceControl
        previous_token = @nodelist.last
-        if previous_token.is_a?(String)
+        if previous_token.is_a? String
          previous_token.rstrip!
        end
      end
@@ -115,57 +69,52 @@ module Liquid
    end

    def render(context)
-      render_to_output_buffer(context, +'')
-    end
-
-    def render_to_output_buffer(context, output)
+      output = []
      context.resource_limits.render_score += @nodelist.length

-      idx = 0
-      while (node = @nodelist[idx])
-        previous_output_size = output.bytesize
+      @nodelist.each do |token|
+        # Break out if we have any unhanded interrupts.
+        break if context.interrupt?

-        case node
-        when String
-          output << node
-        when Variable
-          render_node(context, output, node)
-        when Block
-          render_node(context, node.blank? ? +'' : output, node)
-          break if context.interrupt? # might have happened in a for-block
-        when Continue, Break
+        begin
          # If we get an Interrupt that means the block must stop processing. An
          # Interrupt is any command that stops block execution such as {% break %}
          # or {% continue %}
-          context.push_interrupt(node.interrupt)
-          break
-        else # Other non-Block tags
-          render_node(context, output, node)
-          break if context.interrupt? # might have happened through an include
-        end
-        idx += 1
+          if token.is_a?(Continue) || token.is_a?(Break)
+            context.push_interrupt(token.interrupt)
+            break
+          end

-        raise_if_resource_limits_reached(context, output.bytesize - previous_output_size)
+          node_output = render_node(token, context)
+
+          unless token.is_a?(Block) && token.blank?
+            output << node_output
+          end
+        rescue MemoryError => e
+          raise e
+        rescue UndefinedVariable, UndefinedDropMethod, UndefinedFilter => e
+          context.handle_error(e, token.line_number)
+          output << nil
+        rescue ::StandardError => e
+          line_number = token.is_a?(String) ? nil : token.line_number
+          output << context.handle_error(e, line_number)
+        end
      end

-      output
+      output.join
    end

    private

-    def render_node(context, output, node)
-      node.render_to_output_buffer(context, output)
-    rescue UndefinedVariable, UndefinedDropMethod, UndefinedFilter => e
-      context.handle_error(e, node.line_number)
-    rescue ::StandardError => e
-      line_number = node.is_a?(String) ? nil : node.line_number
-      output << context.handle_error(e, line_number)
-    end
+    def render_node(node, context)
+      node_output = node.is_a?(String) ? node : node.render(context)
+      node_output = node_output.is_a?(Array) ? node_output.join : node_output.to_s

-    def raise_if_resource_limits_reached(context, length)
-      context.resource_limits.render_length += length
-      return unless context.resource_limits.reached?
-      raise MemoryError, "Memory limits exceeded"
+      context.resource_limits.render_length += node_output.length
+      if context.resource_limits.reached?
+        raise MemoryError.new("Memory limits exceeded".freeze)
+      end
+      node_output
    end

    def create_variable(token, parse_context)
@@ -177,11 +126,11 @@ module Liquid
    end

    def raise_missing_tag_terminator(token, parse_context)
-      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_termination", token: token, tag_end: TagEnd.inspect)
+      raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_termination".freeze, token: token, tag_end: TagEnd.inspect))
    end

    def raise_missing_variable_terminator(token, parse_context)
-      raise SyntaxError, parse_context.locale.t("errors.syntax.variable_termination", token: token, tag_end: VariableEnd.inspect)
+      raise SyntaxError.new(parse_context.locale.t("errors.syntax.variable_termination".freeze, token: token, tag_end: VariableEnd.inspect))
    end

    def registered_tags
--- a/lib/liquid/condition.rb
+++ b/lib/liquid/condition.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  # Container for liquid nodes which conveniently wraps decision making logic
  #
@@ -10,35 +8,35 @@ module Liquid
  #
  class Condition #:nodoc:
    @@operators = {
-      '==' => ->(cond, left, right) {  cond.send(:equal_variables, left, right) },
-      '!=' => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
-      '<>' => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
-      '<' => :<,
-      '>' => :>,
-      '>=' => :>=,
-      '<=' => :<=,
-      'contains' => lambda do |_cond, left, right|
+      '=='.freeze => ->(cond, left, right) {  cond.send(:equal_variables, left, right) },
+      '!='.freeze => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
+      '<>'.freeze => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
+      '<'.freeze  => :<,
+      '>'.freeze  => :>,
+      '>='.freeze => :>=,
+      '<='.freeze => :<=,
+      'contains'.freeze => lambda do |cond, left, right|
        if left && right && left.respond_to?(:include?)
          right = right.to_s if left.is_a?(String)
          left.include?(right)
        else
          false
        end
-      end,
+      end
    }

    def self.operators
      @@operators
    end

-    attr_reader :attachment, :child_condition
+    attr_reader :attachment
    attr_accessor :left, :operator, :right

    def initialize(left = nil, operator = nil, right = nil)
      @left = left
      @operator = operator
      @right = right
-      @child_relation = nil
+      @child_relation  = nil
      @child_condition = nil
    end

@@ -80,12 +78,12 @@ module Liquid
    end

    def inspect
-      "#<Condition #{[@left, @operator, @right].compact.join(' ')}>"
+      "#<Condition #{[@left, @operator, @right].compact.join(' '.freeze)}>"
    end

    protected

-    attr_reader :child_relation
+    attr_reader :child_relation, :child_condition

    private

@@ -118,7 +116,7 @@ module Liquid
      left = context.evaluate(left)
      right = context.evaluate(right)

-      operation = self.class.operators[op] || raise(Liquid::ArgumentError, "Unknown operator #{op}")
+      operation = self.class.operators[op] || raise(Liquid::ArgumentError.new("Unknown operator #{op}"))

      if operation.respond_to?(:call)
        operation.call(self, left, right)
@@ -126,19 +124,10 @@ module Liquid
        begin
          left.send(operation, right)
        rescue ::ArgumentError => e
-          raise Liquid::ArgumentError, e.message
+          raise Liquid::ArgumentError.new(e.message)
        end
      end
    end
-
-    class ParseTreeVisitor < Liquid::ParseTreeVisitor
-      def children
-        [
-          @node.left, @node.right,
-          @node.child_condition, @node.attachment
-        ].compact
-      end
-    end
  end

  class ElseCondition < Condition
--- a/lib/liquid/context.rb
+++ b/lib/liquid/context.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  # Context keeps the variable stack and resolves variables, as well as keywords
  #
@@ -14,38 +12,30 @@ module Liquid
  #
  #   context['bob']  #=> nil  class Context
  class Context
-    attr_reader :scopes, :errors, :registers, :environments, :resource_limits, :static_registers, :static_environments
+    attr_reader :scopes, :errors, :registers, :environments, :resource_limits
    attr_accessor :exception_renderer, :template_name, :partial, :global_filter, :strict_variables, :strict_filters

-    # rubocop:disable Metrics/ParameterLists
-    def self.build(environments: {}, outer_scope: {}, registers: {}, rethrow_errors: false, resource_limits: nil, static_environments: {})
-      new(environments, outer_scope, registers, rethrow_errors, resource_limits, static_environments)
-    end
-
-    def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil, static_environments = {})
-      @environments = [environments]
-      @environments.flatten!
-
-      @static_environments = [static_environments].flat_map(&:freeze).freeze
-      @scopes              = [(outer_scope || {})]
-      @registers           = registers
-      @errors              = []
-      @partial             = false
-      @strict_variables    = false
-      @resource_limits     = resource_limits || ResourceLimits.new(Template.default_resource_limits)
-      @base_scope_depth    = 0
+    def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil)
+      @environments     = [environments].flatten
+      @scopes           = [(outer_scope || {})]
+      @registers        = registers
+      @errors           = []
+      @partial          = false
+      @strict_variables = false
+      @resource_limits  = resource_limits || ResourceLimits.new(Template.default_resource_limits)
      squash_instance_assigns_with_environments

+      @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 = []
      @filters = []
      @global_filter = nil
    end
-    # rubocop:enable Metrics/ParameterLists

    def warnings
      @warnings ||= []
@@ -99,7 +89,7 @@ module Liquid
    # Push new local scope on the stack. use <tt>Context#stack</tt> instead
    def push(new_scope = {})
      @scopes.unshift(new_scope)
-      check_overflow
+      raise StackLevelError, "Nesting too deep".freeze if @scopes.length > Block::MAX_DEPTH
    end

    # Merge a hash of variables in the current local scope
@@ -121,30 +111,19 @@ module Liquid
    #   end
    #
    #   context['var]  #=> nil
-    def stack(new_scope = {})
-      push(new_scope)
+    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
+
      yield
    ensure
-      pop
-    end
-
-    # Creates a new context inheriting resource limits, filters, environment etc.,
-    # but with an isolated scope.
-    def new_isolated_subcontext
-      check_overflow
-
-      Context.build(
-        resource_limits: resource_limits,
-        static_environments: static_environments,
-        registers: StaticRegisters.new(registers)
-      ).tap do |subcontext|
-        subcontext.base_scope_depth = base_scope_depth + 1
-        subcontext.exception_renderer = exception_renderer
-        subcontext.filters = @filters
-        subcontext.strainer = nil
-        subcontext.errors = errors
-        subcontext.warnings = warnings
-      end
+      pop if @this_stack_used
+      @this_stack_used = old_stack_used
    end

    def clear_instance_assigns
@@ -153,6 +132,10 @@ 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

@@ -181,13 +164,23 @@ module Liquid
      # This was changed from find() to find_index() because this is a very hot
      # path and find_index() is optimized in MRI to reduce object allocation
      index = @scopes.find_index { |s| s.key?(key) }
+      scope = @scopes[index] if index

-      variable = if index
-        lookup_and_evaluate(@scopes[index], key, raise_on_not_found: raise_on_not_found)
-      else
-        try_variable_find_in_environments(key, raise_on_not_found: raise_on_not_found)
+      variable = nil
+
+      if scope.nil?
+        @environments.each do |e|
+          variable = lookup_and_evaluate(e, key, raise_on_not_found: raise_on_not_found)
+          unless variable.nil?
+            scope = e
+            break
+          end
+        end
      end

+      scope ||= @environments.last || @scopes.last
+      variable ||= lookup_and_evaluate(scope, key, raise_on_not_found: raise_on_not_found)
+
      variable = variable.to_liquid
      variable.context = self if variable.respond_to?(:context=)

@@ -202,48 +195,14 @@ 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
    end

-    protected
-
-    attr_writer :base_scope_depth, :warnings, :errors, :strainer, :filters
-
    private

-    attr_reader :base_scope_depth
-
-    def try_variable_find_in_environments(key, raise_on_not_found:)
-      @environments.each do |environment|
-        found_variable = lookup_and_evaluate(environment, key, raise_on_not_found: raise_on_not_found)
-        Usage.increment("environment_has_a_default_proc") if environment.respond_to?(:default_proc) && environment.default_proc
-        Usage.increment("environment_has_key_but_is_nil") if environment.respond_to?(:key?) && environment.key?(key) && found_variable.nil?
-        if !found_variable.nil? || @strict_variables && raise_on_not_found
-          return found_variable
-        end
-      end
-      @static_environments.each do |environment|
-        found_variable = lookup_and_evaluate(environment, key, raise_on_not_found: raise_on_not_found)
-        Usage.increment("static_environment_has_a_default_proc") if environment.respond_to?(:default_proc) && environment.default_proc
-        Usage.increment("static_environment_has_key_but_is_nil") if environment.respond_to?(:key?) && environment.key?(key) && found_variable.nil?
-        if !found_variable.nil? || @strict_variables && raise_on_not_found
-          return found_variable
-        end
-      end
-      nil
-    end
-
-    def check_overflow
-      raise StackLevelError, "Nesting too deep" if overflow?
-    end
-
-    def overflow?
-      base_scope_depth + @scopes.length > Block::MAX_DEPTH
-    end
-
    def internal_error
      # raise and catch to set backtrace and cause on exception
      raise Liquid::InternalError, 'internal'
--- a/lib/liquid/document.rb
+++ b/lib/liquid/document.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  class Document < BlockBody
    def self.parse(tokens, parse_context)
@@ -9,7 +7,7 @@ module Liquid
    end

    def parse(tokens, parse_context)
-      super do |end_tag_name, _end_tag_params|
+      super do |end_tag_name, end_tag_params|
        unknown_tag(end_tag_name, parse_context) if end_tag_name
      end
    rescue SyntaxError => e
@@ -19,10 +17,10 @@ module Liquid

    def unknown_tag(tag, parse_context)
      case tag
-      when 'else', 'end'
-        raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_outer_tag", tag: tag)
+      when 'else'.freeze, 'end'.freeze
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unexpected_outer_tag".freeze, tag: tag))
      else
-        raise SyntaxError, parse_context.locale.t("errors.syntax.unknown_tag", tag: tag)
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.unknown_tag".freeze, tag: tag))
      end
    end
  end
--- a/lib/liquid/drop.rb
+++ b/lib/liquid/drop.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'set'

 module Liquid
@@ -27,7 +25,7 @@ module Liquid

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

@@ -69,7 +67,7 @@ module Liquid

        if include?(Enumerable)
          blacklist += Enumerable.public_instance_methods
-          blacklist -= [:sort, :count, :first, :min, :max]
+          blacklist -= [:sort, :count, :first, :min, :max, :include?]
        end

        whitelist = [:to_liquid] + (public_instance_methods - blacklist)
--- a/lib/liquid/errors.rb
+++ b/lib/liquid/errors.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  class Error < ::StandardError
    attr_accessor :line_number
@@ -7,7 +5,7 @@ module Liquid
    attr_accessor :markup_context

    def to_s(with_prefix = true)
-      str = +""
+      str = ""
      str << message_prefix if with_prefix
      str << super()

@@ -22,11 +20,11 @@ module Liquid
    private

    def message_prefix
-      str = +""
-      str << if is_a?(SyntaxError)
-        "Liquid syntax error"
+      str = ""
+      if is_a?(SyntaxError)
+        str << "Liquid syntax error"
      else
-        "Liquid error"
+        str << "Liquid error"
      end

      if line_number
--- a/lib/liquid/expression.rb
+++ b/lib/liquid/expression.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  class Expression
    class MethodLiteral
@@ -16,32 +14,28 @@ module Liquid
    end

    LITERALS = {
-      nil => nil, 'nil' => nil, 'null' => nil, '' => nil,
-      'true' => true,
-      'false' => false,
-      'blank' => MethodLiteral.new(:blank?, '').freeze,
-      'empty' => MethodLiteral.new(:empty?, '').freeze
-    }.freeze
-
-    SINGLE_QUOTED_STRING = /\A'(.*)'\z/m
-    DOUBLE_QUOTED_STRING = /\A"(.*)"\z/m
-    INTEGERS_REGEX       = /\A(-?\d+)\z/
-    FLOATS_REGEX         = /\A(-?\d[\d\.]+)\z/
-    RANGES_REGEX         = /\A\((\S+)\.\.(\S+)\)\z/
+      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
+    }

    def self.parse(markup)
      if LITERALS.key?(markup)
        LITERALS[markup]
      else
        case markup
-        when SINGLE_QUOTED_STRING, DOUBLE_QUOTED_STRING
-          Regexp.last_match(1)
-        when INTEGERS_REGEX
-          Regexp.last_match(1).to_i
-        when RANGES_REGEX
-          RangeLookup.parse(Regexp.last_match(1), Regexp.last_match(2))
-        when FLOATS_REGEX
-          Regexp.last_match(1).to_f
+        when /\A'(.*)'\z/m # Single quoted strings
+          $1
+        when /\A"(.*)"\z/m # Double quoted strings
+          $1
+        when /\A(-?\d+)\z/ # Integer and floats
+          $1.to_i
+        when /\A\((\S+)\.\.(\S+)\)\z/ # Ranges
+          RangeLookup.parse($1, $2)
+        when /\A(-?\d[\d\.]+)\z/ # Floats
+          $1.to_f
        else
          VariableLookup.parse(markup)
        end
--- a/lib/liquid/extensions.rb
+++ b/lib/liquid/extensions.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'time'
 require 'date'

@@ -9,12 +7,6 @@ class String # :nodoc:
  end
 end

-class Symbol # :nodoc:
-  def to_liquid
-    to_s
-  end
-end
-
 class Array # :nodoc:
  def to_liquid
    self
--- a/lib/liquid/file_system.rb
+++ b/lib/liquid/file_system.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  # A Liquid file system is a way to let your templates retrieve other templates for use with the include tag.
  #
@@ -46,7 +44,7 @@ module Liquid
  class LocalFileSystem
    attr_accessor :root

-    def initialize(root, pattern = "_%s.liquid")
+    def initialize(root, pattern = "_%s.liquid".freeze)
      @root = root
      @pattern = pattern
    end
@@ -59,9 +57,9 @@ module Liquid
    end

    def full_path(template_path)
-      raise FileSystemError, "Illegal template name '#{template_path}'" unless %r{\A[^./][a-zA-Z0-9_/]+\z}.match?(template_path)
+      raise FileSystemError, "Illegal template name '#{template_path}'" unless template_path =~ /\A[^.\/][a-zA-Z0-9_\/]+\z/

-      full_path = if template_path.include?('/')
+      full_path = if template_path.include?('/'.freeze)
        File.join(root, File.dirname(template_path), @pattern % File.basename(template_path))
      else
        File.join(root, @pattern % template_path)
--- a/lib/liquid/forloop_drop.rb
+++ b/lib/liquid/forloop_drop.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  class ForloopDrop < Drop
    def initialize(name, length, parentloop)
--- a/lib/liquid/i18n.rb
+++ b/lib/liquid/i18n.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'yaml'

 module Liquid
@@ -28,13 +26,13 @@ module Liquid
    def interpolate(name, vars)
      name.gsub(/%\{(\w+)\}/) do
        # raise TranslationError, "Undefined key #{$1} for interpolation in translation #{name}"  unless vars[$1.to_sym]
-        (vars[Regexp.last_match(1).to_sym]).to_s
+        "#{vars[$1.to_sym]}"
      end
    end

    def deep_fetch_translation(name)
-      name.split('.').reduce(locale) do |level, cur|
-        level[cur] || raise(TranslationError, "Translation for #{name} does not exist in locale #{path}")
+      name.split('.'.freeze).reduce(locale) do |level, cur|
+        level[cur] or raise TranslationError, "Translation for #{name} does not exist in locale #{path}"
      end
    end
  end
--- a/lib/liquid/interrupts.rb
+++ b/lib/liquid/interrupts.rb
@@ -1,12 +1,10 @@
-# frozen_string_literal: true
-
 module Liquid
  # An interrupt is any command that breaks processing of a block (ex: a for loop).
  class Interrupt
    attr_reader :message

    def initialize(message = nil)
-      @message = message || "interrupt"
+      @message = message || "interrupt".freeze
    end
  end

--- a/lib/liquid/lexer.rb
+++ b/lib/liquid/lexer.rb
@@ -1,27 +1,24 @@
-# frozen_string_literal: true
-
 require "strscan"
 module Liquid
  class Lexer
    SPECIALS = {
-      '|' => :pipe,
-      '.' => :dot,
-      ':' => :colon,
-      ',' => :comma,
-      '[' => :open_square,
-      ']' => :close_square,
-      '(' => :open_round,
-      ')' => :close_round,
-      '?' => :question,
-      '-' => :dash,
-    }.freeze
+      '|'.freeze => :pipe,
+      '.'.freeze => :dot,
+      ':'.freeze => :colon,
+      ','.freeze => :comma,
+      '['.freeze => :open_square,
+      ']'.freeze => :close_square,
+      '('.freeze => :open_round,
+      ')'.freeze => :close_round,
+      '?'.freeze => :question,
+      '-'.freeze => :dash
+    }
    IDENTIFIER = /[a-zA-Z_][\w-]*\??/
    SINGLE_STRING_LITERAL = /'[^\']*'/
    DOUBLE_STRING_LITERAL = /"[^\"]*"/
    NUMBER_LITERAL = /-?\d+(\.\d+)?/
    DOTDOT = /\.\./
    COMPARISON_OPERATOR = /==|!=|<>|<=?|>=?|contains(?=\s)/
-    WHITESPACE_OR_NOTHING = /\s*/

    def initialize(input)
      @ss = StringScanner.new(input)
@@ -31,23 +28,18 @@ module Liquid
      @output = []

      until @ss.eos?
-        @ss.skip(WHITESPACE_OR_NOTHING)
+        @ss.skip(/\s*/)
        break if @ss.eos?
-        tok = if (t = @ss.scan(COMPARISON_OPERATOR))
-          [:comparison, t]
-        elsif (t = @ss.scan(SINGLE_STRING_LITERAL))
-          [:string, t]
-        elsif (t = @ss.scan(DOUBLE_STRING_LITERAL))
-          [:string, t]
-        elsif (t = @ss.scan(NUMBER_LITERAL))
-          [:number, t]
-        elsif (t = @ss.scan(IDENTIFIER))
-          [:id, t]
-        elsif (t = @ss.scan(DOTDOT))
-          [:dotdot, t]
+        tok = case
+        when t = @ss.scan(COMPARISON_OPERATOR) then [:comparison, t]
+        when t = @ss.scan(SINGLE_STRING_LITERAL) then [:string, t]
+        when t = @ss.scan(DOUBLE_STRING_LITERAL) then [:string, t]
+        when t = @ss.scan(NUMBER_LITERAL) then [:number, t]
+        when t = @ss.scan(IDENTIFIER) then [:id, t]
+        when t = @ss.scan(DOTDOT) then [:dotdot, t]
        else
          c = @ss.getch
-          if (s = SPECIALS[c])
+          if s = SPECIALS[c]
            [s, c]
          else
            raise SyntaxError, "Unexpected character #{c}"
--- a/lib/liquid/locales/en.yml
+++ b/lib/liquid/locales/en.yml
@@ -14,7 +14,7 @@
      if: "Syntax Error in tag 'if' - Valid syntax: if [expression]"
      include: "Error in tag 'include' - Valid syntax: include '[template]' (with|for) [object|collection]"
      unknown_tag: "Unknown tag '%{tag}'"
-      invalid_delimiter: "'%{tag}' is not a valid delimiter for %{block_name} tags. use %{block_delimiter}"
+      invalid_delimiter: "'end' is not a valid delimiter for %{block_name} tags. use %{block_delimiter}"
      unexpected_else: "%{block_name} tag does not expect 'else' tag"
      unexpected_outer_tag: "Unexpected outer '%{tag}' tag"
      tag_termination: "Tag '%{token}' was not properly terminated with regexp: %{tag_end}"
@@ -22,6 +22,5 @@
      tag_never_closed: "'%{block_name}' tag was never closed"
      meta_syntax_error: "Liquid syntax error: #{e.message}"
      table_row: "Syntax Error in 'table_row loop' - Valid syntax: table_row [item] in [collection] cols=3"
-      render: "Syntax error in tag 'render' - Template name must be a quoted string"
    argument:
      include: "Argument error in tag 'include' - Illegal template name"
--- a/lib/liquid/parse_context.rb
+++ b/lib/liquid/parse_context.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  class ParseContext
    attr_accessor :locale, :line_number, :trim_whitespace, :depth
@@ -21,6 +19,7 @@ module Liquid
      @partial = value
      @options = value ? partial_options : @template_options
      @error_mode = @options[:error_mode] || Template.error_mode
+      value
    end

    def partial_options
@@ -29,7 +28,7 @@ module Liquid
        if dont_pass == true
          { locale: locale }
        elsif dont_pass.is_a?(Array)
-          @template_options.reject { |k, _v| dont_pass.include?(k) }
+          @template_options.reject { |k, v| dont_pass.include?(k) }
        else
          @template_options
        end
--- a/lib/liquid/parse_tree_visitor.rb
+++ b/lib/liquid/parse_tree_visitor.rb
@@ -1,42 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  class ParseTreeVisitor
-    def self.for(node, callbacks = Hash.new(proc {}))
-      if defined?(node.class::ParseTreeVisitor)
-        node.class::ParseTreeVisitor
-      else
-        self
-      end.new(node, callbacks)
-    end
-
-    def initialize(node, callbacks)
-      @node = node
-      @callbacks = callbacks
-    end
-
-    def add_callback_for(*classes, &block)
-      callback = block
-      callback = ->(node, _) { yield node } if block.arity.abs == 1
-      callback = ->(_, _) { yield } if block.arity.zero?
-      classes.each { |klass| @callbacks[klass] = callback }
-      self
-    end
-
-    def visit(context = nil)
-      children.map do |node|
-        item, new_context = @callbacks[node.class].call(node, context)
-        [
-          item,
-          ParseTreeVisitor.for(node, @callbacks).visit(new_context || context),
-        ]
-      end
-    end
-
-    protected
-
-    def children
-      @node.respond_to?(:nodelist) ? Array(@node.nodelist) : []
-    end
-  end
-end
--- a/lib/liquid/parser.rb
+++ b/lib/liquid/parser.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  class Parser
    def initialize(input)
@@ -46,14 +44,11 @@ module Liquid
      tok[0] == type
    end

-    SINGLE_TOKEN_EXPRESSION_TYPES = [:string, :number].freeze
-    private_constant :SINGLE_TOKEN_EXPRESSION_TYPES
-
    def expression
      token = @tokens[@p]
      if token[0] == :id
        variable_signature
-      elsif SINGLE_TOKEN_EXPRESSION_TYPES.include?(token[0])
+      elsif [:string, :number].include? token[0]
        consume
      elsif token.first == :open_round
        consume
@@ -68,10 +63,10 @@ module Liquid
    end

    def argument
-      str = +""
+      str = ""
      # might be a keyword argument (identifier: expression)
      if look(:id) && look(:colon, 1)
-        str << consume << consume << ' '
+        str << consume << consume << ' '.freeze
      end

      str << expression
--- a/lib/liquid/parser_switching.rb
+++ b/lib/liquid/parser_switching.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  module ParserSwitching
    def parse_with_selected_parser(markup)
--- a/lib/liquid/partial_cache.rb
+++ b/lib/liquid/partial_cache.rb
@@ -1,20 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  class PartialCache
-    def self.load(template_name, context:, parse_context:)
-      cached_partials = (context.registers[:cached_partials] ||= {})
-      cached = cached_partials[template_name]
-      return cached if cached
-
-      file_system = (context.registers[:file_system] ||= Liquid::Template.file_system)
-      source = file_system.read_template_file(template_name)
-      parse_context.partial = true
-
-      partial = Liquid::Template.parse(source, parse_context)
-      cached_partials[template_name] = partial
-    ensure
-      parse_context.partial = false
-    end
-  end
-end
--- a/lib/liquid/profiler.rb
+++ b/lib/liquid/profiler.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'liquid/profiler/hooks'

 module Liquid
--- a/lib/liquid/profiler/hooks.rb
+++ b/lib/liquid/profiler/hooks.rb
@@ -1,10 +1,8 @@
-# frozen_string_literal: true
-
 module Liquid
  class BlockBody
-    def render_node_with_profiling(context, output, node)
+    def render_node_with_profiling(node, context)
      Profiler.profile_node_render(node) do
-        render_node_without_profiling(context, output, node)
+        render_node_without_profiling(node, context)
      end
    end

@@ -13,13 +11,13 @@ module Liquid
  end

  class Include < Tag
-    def render_to_output_buffer_with_profiling(context, output)
+    def render_with_profiling(context)
      Profiler.profile_children(context.evaluate(@template_name_expr).to_s) do
-        render_to_output_buffer_without_profiling(context, output)
+        render_without_profiling(context)
      end
    end

-    alias_method :render_to_output_buffer_without_profiling, :render_to_output_buffer
-    alias_method :render_to_output_buffer, :render_to_output_buffer_with_profiling
+    alias_method :render_without_profiling, :render
+    alias_method :render, :render_with_profiling
  end
 end
--- a/lib/liquid/range_lookup.rb
+++ b/lib/liquid/range_lookup.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  class RangeLookup
    def self.parse(start_markup, end_markup)
--- a/lib/liquid/resource_limits.rb
+++ b/lib/liquid/resource_limits.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  class ResourceLimits
    attr_accessor :render_length, :render_score, :assign_score,
--- a/lib/liquid/standardfilters.rb
+++ b/lib/liquid/standardfilters.rb
@@ -1,24 +1,16 @@
-# frozen_string_literal: true
-
 require 'cgi'
 require 'bigdecimal'

 module Liquid
  module StandardFilters
    HTML_ESCAPE = {
-      '&' => '&amp;',
-      '>' => '&gt;',
-      '<' => '&lt;',
-      '"' => '&quot;',
-      "'" => '&#39;',
-    }.freeze
+      '&'.freeze => '&amp;'.freeze,
+      '>'.freeze => '&gt;'.freeze,
+      '<'.freeze => '&lt;'.freeze,
+      '"'.freeze => '&quot;'.freeze,
+      "'".freeze => '&#39;'.freeze
+    }
    HTML_ESCAPE_ONCE_REGEXP = /["><']|&(?!([a-zA-Z]+|(#\d+));)/
-    STRIP_HTML_BLOCKS = Regexp.union(
-      %r{<script.*?</script>}m,
-      /<!--.*?-->/m,
-      %r{<style.*?</style>}m
-    )
-    STRIP_HTML_TAGS = /<.*?>/m

    # Return the size of an array or of an string
    def size(input)
@@ -54,12 +46,7 @@ module Liquid
    end

    def url_decode(input)
-      return if input.nil?
-
-      result = CGI.unescape(input.to_s)
-      raise Liquid::ArgumentError, "invalid byte sequence in #{result.encoding}" unless result.valid_encoding?
-
-      result
+      CGI.unescape(input.to_s) unless input.nil?
    end

    def slice(input, offset, length = nil)
@@ -74,23 +61,23 @@ module Liquid
    end

    # Truncate a string down to x characters
-    def truncate(input, length = 50, truncate_string = "...")
+    def truncate(input, length = 50, truncate_string = "...".freeze)
      return if input.nil?
      input_str = input.to_s
      length = Utils.to_integer(length)
      truncate_string_str = truncate_string.to_s
      l = length - truncate_string_str.length
      l = 0 if l < 0
-      input_str.length > length ? input_str[0...l].concat(truncate_string_str) : input_str
+      input_str.length > length ? input_str[0...l] + truncate_string_str : input_str
    end

-    def truncatewords(input, words = 15, truncate_string = "...")
+    def truncatewords(input, words = 15, truncate_string = "...".freeze)
      return if input.nil?
      wordlist = input.to_s.split
      words = Utils.to_integer(words)
      l = words - 1
      l = 0 if l < 0
-      wordlist.length > l ? wordlist[0..l].join(" ").concat(truncate_string.to_s) : input
+      wordlist.length > l ? wordlist[0..l].join(" ".freeze) + truncate_string.to_s : input
    end

    # Split input string into an array of substrings separated by given pattern.
@@ -115,19 +102,17 @@ module Liquid
    end

    def strip_html(input)
-      empty = ''
-      result = input.to_s.gsub(STRIP_HTML_BLOCKS, empty)
-      result.gsub!(STRIP_HTML_TAGS, empty)
-      result
+      empty = ''.freeze
+      input.to_s.gsub(/<script.*?<\/script>/m, empty).gsub(/<!--.*?-->/m, empty).gsub(/<style.*?<\/style>/m, empty).gsub(/<.*?>/m, empty)
    end

    # Remove all newlines from the string
    def strip_newlines(input)
-      input.to_s.gsub(/\r?\n/, '')
+      input.to_s.gsub(/\r?\n/, ''.freeze)
    end

    # Join elements of the array with certain character between them
-    def join(input, glue = ' ')
+    def join(input, glue = ' '.freeze)
      InputIterator.new(input).join(glue)
    end

@@ -135,18 +120,19 @@ module Liquid
    # provide optional property with which to sort an array of hashes or drops
    def sort(input, property = nil)
      ary = InputIterator.new(input)
-
-      return [] if ary.empty?
-
      if property.nil?
+        ary.sort
+      elsif ary.empty? # The next two cases assume a non-empty array.
+        []
+      elsif ary.first.respond_to?(:[]) && !ary.first[property].nil?
        ary.sort do |a, b|
-          nil_safe_compare(a, b)
-        end
-      elsif ary.all? { |el| el.respond_to?(:[]) }
-        begin
-          ary.sort { |a, b| nil_safe_compare(a[property], b[property]) }
-        rescue TypeError
-          raise_property_error(property)
+          a = a[property]
+          b = b[property]
+          if a && b
+            a <=> b
+          else
+            a ? -1 : 1
+          end
        end
      end
    end
@@ -156,40 +142,12 @@ module Liquid
    def sort_natural(input, property = nil)
      ary = InputIterator.new(input)

-      return [] if ary.empty?
-
      if property.nil?
-        ary.sort do |a, b|
-          nil_safe_casecmp(a, b)
-        end
-      elsif ary.all? { |el| el.respond_to?(:[]) }
-        begin
-          ary.sort { |a, b| nil_safe_casecmp(a[property], b[property]) }
-        rescue TypeError
-          raise_property_error(property)
-        end
-      end
-    end
-
-    # Filter the elements of an array to those with a certain property value.
-    # By default the target is any truthy value.
-    def where(input, property, target_value = nil)
-      ary = InputIterator.new(input)
-
-      if ary.empty?
+        ary.sort { |a, b| a.casecmp(b) }
+      elsif ary.empty? # The next two cases assume a non-empty array.
        []
-      elsif ary.first.respond_to?(:[]) && target_value.nil?
-        begin
-          ary.select { |item| item[property] }
-        rescue TypeError
-          raise_property_error(property)
-        end
-      elsif ary.first.respond_to?(:[])
-        begin
-          ary.select { |item| item[property] == target_value }
-        rescue TypeError
-          raise_property_error(property)
-        end
+      elsif ary.first.respond_to?(:[]) && !ary.first[property].nil?
+        ary.sort { |a, b| a[property].casecmp(b[property]) }
      end
    end

@@ -203,11 +161,7 @@ module Liquid
      elsif ary.empty? # The next two cases assume a non-empty array.
        []
      elsif ary.first.respond_to?(:[])
-        begin
-          ary.uniq { |a| a[property] }
-        rescue TypeError
-          raise_property_error(property)
-        end
+        ary.uniq{ |a| a[property] }
      end
    end

@@ -222,15 +176,13 @@ module Liquid
      InputIterator.new(input).map do |e|
        e = e.call if e.is_a?(Proc)

-        if property == "to_liquid"
+        if property == "to_liquid".freeze
          e
        elsif e.respond_to?(:[])
          r = e[property]
          r.is_a?(Proc) ? r.call : r
        end
      end
-    rescue TypeError
-      raise_property_error(property)
    end

    # Remove nils within an array
@@ -243,32 +195,28 @@ module Liquid
      elsif ary.empty? # The next two cases assume a non-empty array.
        []
      elsif ary.first.respond_to?(:[])
-        begin
-          ary.reject { |a| a[property].nil? }
-        rescue TypeError
-          raise_property_error(property)
-        end
+        ary.reject{ |a| a[property].nil? }
      end
    end

    # Replace occurrences of a string with another
-    def replace(input, string, replacement = '')
+    def replace(input, string, replacement = ''.freeze)
      input.to_s.gsub(string.to_s, replacement.to_s)
    end

    # Replace the first occurrences of a string with another
-    def replace_first(input, string, replacement = '')
+    def replace_first(input, string, replacement = ''.freeze)
      input.to_s.sub(string.to_s, replacement.to_s)
    end

    # remove a substring
    def remove(input, string)
-      input.to_s.gsub(string.to_s, '')
+      input.to_s.gsub(string.to_s, ''.freeze)
    end

    # remove the first occurrences of a substring
    def remove_first(input, string)
-      input.to_s.sub(string.to_s, '')
+      input.to_s.sub(string.to_s, ''.freeze)
    end

    # add one string to another
@@ -278,7 +226,7 @@ module Liquid

    def concat(input, array)
      unless array.respond_to?(:to_ary)
-        raise ArgumentError, "concat filter requires an array argument"
+        raise ArgumentError.new("concat filter requires an array argument")
      end
      InputIterator.new(input).concat(array)
    end
@@ -290,7 +238,7 @@ module Liquid

    # Add <br /> tags in front of all newlines in input string
    def newline_to_br(input)
-      input.to_s.gsub(/\n/, "<br />\n")
+      input.to_s.gsub(/\n/, "<br />\n".freeze)
    end

    # Reformat a date using Ruby's core Time#strftime( string ) -> string
@@ -327,7 +275,7 @@ module Liquid
    def date(input, format)
      return input if format.to_s.empty?

-      return input unless (date = Utils.to_date(input))
+      return input unless date = Utils.to_date(input)

      date.strftime(format.to_s)
    end
@@ -405,23 +353,7 @@ module Liquid
      raise Liquid::FloatDomainError, e.message
    end

-    def at_least(input, n)
-      min_value = Utils.to_number(n)
-
-      result = Utils.to_number(input)
-      result = min_value if min_value > result
-      result.is_a?(BigDecimal) ? result.to_f : result
-    end
-
-    def at_most(input, n)
-      max_value = Utils.to_number(n)
-
-      result = Utils.to_number(input)
-      result = max_value if max_value < result
-      result.is_a?(BigDecimal) ? result.to_f : result
-    end
-
-    def default(input, default_value = '')
+    def default(input, default_value = ''.freeze)
      if !input || input.respond_to?(:empty?) && input.empty?
        default_value
      else
@@ -431,31 +363,11 @@ module Liquid

    private

-    def raise_property_error(property)
-      raise Liquid::ArgumentError, "cannot select the property '#{property}'"
-    end
-
    def apply_operation(input, operand, operation)
      result = Utils.to_number(input).send(operation, Utils.to_number(operand))
      result.is_a?(BigDecimal) ? result.to_f : result
    end

-    def nil_safe_compare(a, b)
-      if !a.nil? && !b.nil?
-        a <=> b
-      else
-        a.nil? ? 1 : -1
-      end
-    end
-
-    def nil_safe_casecmp(a, b)
-      if !a.nil? && !b.nil?
-        a.to_s.casecmp(b.to_s)
-      else
-        a.nil? ? 1 : -1
-      end
-    end
-
    class InputIterator
      include Enumerable

--- a/lib/liquid/static_registers.rb
+++ b/lib/liquid/static_registers.rb
@@ -1,36 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  class StaticRegisters
-    attr_reader :static, :registers
-
-    def initialize(registers = {})
-      @static = registers.is_a?(StaticRegisters) ? registers.static : registers
-      @registers = {}
-    end
-
-    def []=(key, value)
-      @registers[key] = value
-    end
-
-    def [](key)
-      if @registers.key?(key)
-        @registers[key]
-      else
-        @static[key]
-      end
-    end
-
-    def delete(key)
-      @registers.delete(key)
-    end
-
-    def fetch(key, default = nil)
-      key?(key) ? self[key] : default
-    end
-
-    def key?(key)
-      @registers.key?(key) || @static.key?(key)
-    end
-  end
-end
--- a/lib/liquid/strainer.rb
+++ b/lib/liquid/strainer.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'set'

 module Liquid
@@ -29,7 +27,7 @@ module Liquid

    def self.add_filter(filter)
      raise ArgumentError, "Expected module but got: #{filter.class}" unless filter.is_a?(Module)
-      unless include?(filter)
+      unless self.include?(filter)
        invokable_non_public_methods = (filter.private_instance_methods + filter.protected_instance_methods).select { |m| invokable?(m) }
        if invokable_non_public_methods.any?
          raise MethodOverrideError, "Filter overrides registered public methods as non public: #{invokable_non_public_methods.join(', ')}"
@@ -56,7 +54,7 @@ module Liquid
    def invoke(method, *args)
      if self.class.invokable?(method)
        send(method, *args)
-      elsif @context&.strict_filters
+      elsif @context && @context.strict_filters
        raise Liquid::UndefinedFilter, "undefined filter #{method}"
      else
        args.first
--- a/lib/liquid/tablerowloop_drop.rb
+++ b/lib/liquid/tablerowloop_drop.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  class TablerowloopDrop < Drop
    def initialize(length, cols)
--- a/lib/liquid/tag.rb
+++ b/lib/liquid/tag.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  class Tag
    attr_reader :nodelist, :tag_name, :line_number, :parse_context
@@ -7,8 +5,8 @@ module Liquid
    include ParserSwitching

    class << self
-      def parse(tag_name, markup, tokenizer, parse_context)
-        tag = new(tag_name, markup, parse_context)
+      def parse(tag_name, markup, tokenizer, options)
+        tag = new(tag_name, markup, options)
        tag.parse(tokenizer)
        tag
      end
@@ -35,15 +33,7 @@ module Liquid
    end

    def render(_context)
-      ''
-    end
-
-    # For backwards compatibility with custom tags. In a future release, the semantics
-    # of the `render_to_output_buffer` method will become the default and the `render`
-    # method will be removed.
-    def render_to_output_buffer(context, output)
-      output << render(context)
-      output
+      ''.freeze
    end

    def blank?
--- a/lib/liquid/tags/assign.rb
+++ b/lib/liquid/tags/assign.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  # Assign sets a variable in your template.
  #
@@ -12,27 +10,21 @@ module Liquid
  class Assign < Tag
    Syntax = /(#{VariableSignature}+)\s*=\s*(.*)\s*/om

-    def self.syntax_error_translation_key
-      "errors.syntax.assign"
-    end
-
-    attr_reader :to, :from
-
    def initialize(tag_name, markup, options)
      super
      if markup =~ Syntax
-        @to = Regexp.last_match(1)
-        @from = Variable.new(Regexp.last_match(2), options)
+        @to = $1
+        @from = Variable.new($2, options)
      else
-        raise SyntaxError, options[:locale].t(self.class.syntax_error_translation_key)
+        raise SyntaxError.new options[:locale].t("errors.syntax.assign".freeze)
      end
    end

-    def render_to_output_buffer(context, output)
+    def render(context)
      val = @from.render(context)
      context.scopes.last[@to] = val
      context.resource_limits.assign_score += assign_score_of(val)
-      output
+      ''.freeze
    end

    def blank?
@@ -43,7 +35,7 @@ module Liquid

    def assign_score_of(val)
      if val.instance_of?(String)
-        val.bytesize
+        val.length
      elsif val.instance_of?(Array) || val.instance_of?(Hash)
        sum = 1
        # Uses #each to avoid extra allocations.
@@ -53,13 +45,7 @@ module Liquid
        1
      end
    end
-
-    class ParseTreeVisitor < Liquid::ParseTreeVisitor
-      def children
-        [@node.from]
-      end
-    end
  end

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

-  Template.register_tag('break', Break)
+  Template.register_tag('break'.freeze, Break)
 end
--- a/lib/liquid/tags/capture.rb
+++ b/lib/liquid/tags/capture.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  # Capture stores the result of a block into a variable without rendering it inplace.
  #
@@ -18,18 +16,17 @@ module Liquid
    def initialize(tag_name, markup, options)
      super
      if markup =~ Syntax
-        @to = Regexp.last_match(1)
+        @to = $1
      else
-        raise SyntaxError, options[:locale].t("errors.syntax.capture")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.capture"))
      end
    end

-    def render_to_output_buffer(context, output)
-      previous_output_size = output.bytesize
-      super
+    def render(context)
+      output = super
      context.scopes.last[@to] = output
-      context.resource_limits.assign_score += (output.bytesize - previous_output_size)
-      output
+      context.resource_limits.assign_score += output.length
+      ''.freeze
    end

    def blank?
@@ -37,5 +34,5 @@ module Liquid
    end
  end

-  Template.register_tag('capture', Capture)
+  Template.register_tag('capture'.freeze, Capture)
 end
--- a/lib/liquid/tags/case.rb
+++ b/lib/liquid/tags/case.rb
@@ -1,26 +1,24 @@
-# frozen_string_literal: true
-
 module Liquid
  class Case < Block
    Syntax     = /(#{QuotedFragment})/o
    WhenSyntax = /(#{QuotedFragment})(?:(?:\s+or\s+|\s*\,\s*)(#{QuotedFragment}.*))?/om

-    attr_reader :blocks, :left
-
    def initialize(tag_name, markup, options)
      super
      @blocks = []

      if markup =~ Syntax
-        @left = Expression.parse(Regexp.last_match(1))
+        @left = Expression.parse($1)
      else
-        raise SyntaxError, options[:locale].t("errors.syntax.case")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.case".freeze))
      end
    end

    def parse(tokens)
      body = BlockBody.new
-      body = @blocks.last.attachment while parse_body(body, tokens)
+      while parse_body(body, tokens)
+        body = @blocks.last.attachment
+      end
    end

    def nodelist
@@ -29,28 +27,30 @@ module Liquid

    def unknown_tag(tag, markup, tokens)
      case tag
-      when 'when'
+      when 'when'.freeze
        record_when_condition(markup)
-      when 'else'
+      when 'else'.freeze
        record_else_condition(markup)
      else
        super
      end
    end

-    def render_to_output_buffer(context, output)
-      execute_else_block = true
+    def render(context)
+      context.stack do
+        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)
+        output = ''
+        @blocks.each do |block|
+          if block.else?
+            return block.attachment.render(context) if execute_else_block
+          elsif block.evaluate(context)
+            execute_else_block = false
+            output << block.attachment.render(context)
+          end
        end
+        output
      end
-
-      output
    end

    private
@@ -60,12 +60,12 @@ module Liquid

      while markup
        unless markup =~ WhenSyntax
-          raise SyntaxError, options[:locale].t("errors.syntax.case_invalid_when")
+          raise SyntaxError.new(options[:locale].t("errors.syntax.case_invalid_when".freeze))
        end

-        markup = Regexp.last_match(2)
+        markup = $2

-        block = Condition.new(@left, '==', Expression.parse(Regexp.last_match(1)))
+        block = Condition.new(@left, '=='.freeze, Expression.parse($1))
        block.attach(body)
        @blocks << block
      end
@@ -73,20 +73,14 @@ module Liquid

    def record_else_condition(markup)
      unless markup.strip.empty?
-        raise SyntaxError, options[:locale].t("errors.syntax.case_invalid_else")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.case_invalid_else".freeze))
      end

      block = ElseCondition.new
      block.attach(BlockBody.new)
      @blocks << block
    end
-
-    class ParseTreeVisitor < Liquid::ParseTreeVisitor
-      def children
-        [@node.left] + @node.blocks
-      end
-    end
  end

-  Template.register_tag('case', Case)
+  Template.register_tag('case'.freeze, Case)
 end
--- a/lib/liquid/tags/comment.rb
+++ b/lib/liquid/tags/comment.rb
@@ -1,9 +1,7 @@
-# frozen_string_literal: true
-
 module Liquid
  class Comment < Block
-    def render_to_output_buffer(_context, output)
-      output
+    def render(_context)
+      ''.freeze
    end

    def unknown_tag(_tag, _markup, _tokens)
@@ -14,5 +12,5 @@ module Liquid
    end
  end

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

-  Template.register_tag('continue', Continue)
+  Template.register_tag('continue'.freeze, Continue)
 end
--- a/lib/liquid/tags/cycle.rb
+++ b/lib/liquid/tags/cycle.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  # Cycle is usually used within a loop to alternate between values, like colors or DOM classes.
  #
@@ -17,43 +15,32 @@ module Liquid
    SimpleSyntax = /\A#{QuotedFragment}+/o
    NamedSyntax  = /\A(#{QuotedFragment})\s*\:\s*(.*)/om

-    attr_reader :variables
-
    def initialize(tag_name, markup, options)
      super
      case markup
      when NamedSyntax
-        @variables = variables_from_string(Regexp.last_match(2))
-        @name = Expression.parse(Regexp.last_match(1))
+        @variables = variables_from_string($2)
+        @name = Expression.parse($1)
      when SimpleSyntax
        @variables = variables_from_string(markup)
        @name = @variables.to_s
      else
-        raise SyntaxError, options[:locale].t("errors.syntax.cycle")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.cycle".freeze))
      end
    end

-    def render_to_output_buffer(context, output)
-      context.registers[:cycle] ||= {}
+    def render(context)
+      context.registers[:cycle] ||= Hash.new(0)

-      key = context.evaluate(@name)
-      iteration = context.registers[:cycle][key].to_i
-
-      val = context.evaluate(@variables[iteration])
-
-      if val.is_a?(Array)
-        val = val.join
-      elsif !val.is_a?(String)
-        val = val.to_s
+      context.stack do
+        key = context.evaluate(@name)
+        iteration = context.registers[:cycle][key]
+        result = context.evaluate(@variables[iteration])
+        iteration += 1
+        iteration  = 0 if iteration >= @variables.size
+        context.registers[:cycle][key] = iteration
+        result
      end
-
-      output << val
-
-      iteration += 1
-      iteration  = 0 if iteration >= @variables.size
-      context.registers[:cycle][key] = iteration
-
-      output
    end

    private
@@ -61,15 +48,9 @@ module Liquid
    def variables_from_string(markup)
      markup.split(',').collect do |var|
        var =~ /\s*(#{QuotedFragment})\s*/o
-        Regexp.last_match(1) ? Expression.parse(Regexp.last_match(1)) : nil
+        $1 ? Expression.parse($1) : nil
      end.compact
    end
-
-    class ParseTreeVisitor < Liquid::ParseTreeVisitor
-      def children
-        Array(@node.variables)
-      end
-    end
  end

  Template.register_tag('cycle', Cycle)
--- a/lib/liquid/tags/decrement.rb
+++ b/lib/liquid/tags/decrement.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  # decrement is used in a place where one needs to insert a counter
  #     into a template, and needs the counter to survive across
@@ -25,14 +23,13 @@ module Liquid
      @variable = markup.strip
    end

-    def render_to_output_buffer(context, output)
+    def render(context)
      value = context.environments.first[@variable] ||= 0
      value -= 1
      context.environments.first[@variable] = value
-      output << value.to_s
-      output
+      value.to_s
    end
  end

-  Template.register_tag('decrement', Decrement)
+  Template.register_tag('decrement'.freeze, Decrement)
 end
--- a/lib/liquid/tags/echo.rb
+++ b/lib/liquid/tags/echo.rb
@@ -1,26 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  # Echo outputs an expression
-  #
-  #   {% echo monkey %}
-  #   {% echo user.name %}
-  #
-  # This is identical to variable output syntax, like {{ foo }}, but works
-  # inside {% liquid %} tags. The full syntax is supported, including filters:
-  #
-  #   {% echo user | link %}
-  #
-  class Echo < Tag
-    def initialize(tag_name, markup, parse_context)
-      super
-      @variable = Variable.new(markup, parse_context)
-    end
-
-    def render(context)
-      @variable.render_to_output_buffer(context, +'')
-    end
-  end
-
-  Template.register_tag('echo', Echo)
-end
--- a/lib/liquid/tags/for.rb
+++ b/lib/liquid/tags/for.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  # "For" iterates over an array or collection.
  # Several useful variables are available to you within the loop.
@@ -48,7 +46,8 @@ module Liquid
  class For < Block
    Syntax = /\A(#{VariableSegment}+)\s+in\s+(#{QuotedFragment}+)\s*(reversed)?/o

-    attr_reader :collection_name, :variable_name, :limit, :from
+    attr_reader :collection_name
+    attr_reader :variable_name

    def initialize(tag_name, markup, options)
      super
@@ -68,51 +67,49 @@ module Liquid
    end

    def unknown_tag(tag, markup, tokens)
-      return super unless tag == 'else'
+      return super unless tag == 'else'.freeze
      @else_block = BlockBody.new
    end

-    def render_to_output_buffer(context, output)
+    def render(context)
      segment = collection_segment(context)

      if segment.empty?
-        render_else(context, output)
+        render_else(context)
      else
-        render_segment(context, output, segment)
+        render_segment(context, segment)
      end
-
-      output
    end

    protected

    def lax_parse(markup)
      if markup =~ Syntax
-        @variable_name = Regexp.last_match(1)
-        collection_name = Regexp.last_match(2)
-        @reversed = !!Regexp.last_match(3)
+        @variable_name = $1
+        collection_name = $2
+        @reversed = !!$3
        @name = "#{@variable_name}-#{collection_name}"
        @collection_name = Expression.parse(collection_name)
        markup.scan(TagAttributes) do |key, value|
          set_attribute(key, value)
        end
      else
-        raise SyntaxError, options[:locale].t("errors.syntax.for")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.for".freeze))
      end
    end

    def strict_parse(markup)
      p = Parser.new(markup)
      @variable_name = p.consume(:id)
-      raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_in") unless p.id?('in')
+      raise SyntaxError.new(options[:locale].t("errors.syntax.for_invalid_in".freeze)) unless p.id?('in'.freeze)
      collection_name = p.expression
      @name = "#{@variable_name}-#{collection_name}"
      @collection_name = Expression.parse(collection_name)
-      @reversed = p.id?('reversed')
+      @reversed = p.id?('reversed'.freeze)

      while p.look(:id) && p.look(:colon, 1)
-        unless (attribute = p.id?('limit') || p.id?('offset'))
-          raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_attribute")
+        unless attribute = p.id?('limit'.freeze) || p.id?('offset'.freeze)
+          raise SyntaxError.new(options[:locale].t("errors.syntax.for_invalid_attribute".freeze))
        end
        p.consume
        set_attribute(attribute, p.expression)
@@ -123,28 +120,19 @@ module Liquid
    private

    def collection_segment(context)
-      offsets = context.registers[:for] ||= {}
+      offsets = context.registers[:for] ||= Hash.new(0)

      from = if @from == :continue
        offsets[@name].to_i
      else
-        from_value = context.evaluate(@from)
-        if from_value.nil?
-          0
-        else
-          Utils.to_integer(from_value)
-        end
+        context.evaluate(@from).to_i
      end

      collection = context.evaluate(@collection_name)
-      collection = collection.to_a if collection.is_a?(Range)
+      collection = collection.step(1).to_a if collection.is_a?(Range)

-      limit_value = context.evaluate(@limit)
-      to = if limit_value.nil?
-        nil
-      else
-        Utils.to_integer(limit_value) + from
-      end
+      limit = context.evaluate(@limit)
+      to = limit ? limit.to_i + from : nil

      segment = Utils.slice_collection(collection, from, to)
      segment.reverse! if @reversed
@@ -154,64 +142,57 @@ module Liquid
      segment
    end

-    def render_segment(context, output, segment)
+    def render_segment(context, segment)
      for_stack = context.registers[:for_stack] ||= []
      length = segment.length

+      result = ''
+
      context.stack do
        loop_vars = Liquid::ForloopDrop.new(@name, length, for_stack[-1])

        for_stack.push(loop_vars)

        begin
-          context['forloop'] = loop_vars
+          context['forloop'.freeze] = loop_vars

-          segment.each do |item|
+          segment.each_with_index do |item, index|
            context[@variable_name] = item
-            @for_block.render_to_output_buffer(context, output)
+            result << @for_block.render(context)
            loop_vars.send(:increment!)

            # Handle any interrupts if they exist.
-            next unless context.interrupt?
-            interrupt = context.pop_interrupt
-            break if interrupt.is_a?(BreakInterrupt)
-            next if interrupt.is_a?(ContinueInterrupt)
+            if context.interrupt?
+              interrupt = context.pop_interrupt
+              break if interrupt.is_a? BreakInterrupt
+              next if interrupt.is_a? ContinueInterrupt
+            end
          end
        ensure
          for_stack.pop
        end
      end

-      output
+      result
    end

    def set_attribute(key, expr)
      case key
-      when 'offset'
-        @from = if expr == 'continue'
+      when 'offset'.freeze
+        @from = if expr == 'continue'.freeze
          :continue
        else
          Expression.parse(expr)
        end
-      when 'limit'
+      when 'limit'.freeze
        @limit = Expression.parse(expr)
      end
    end

-    def render_else(context, output)
-      if @else_block
-        @else_block.render_to_output_buffer(context, output)
-      else
-        output
-      end
-    end
-
-    class ParseTreeVisitor < Liquid::ParseTreeVisitor
-      def children
-        (super + [@node.limit, @node.from, @node.collection_name]).compact
-      end
+    def render_else(context)
+      @else_block ? @else_block.render(context) : ''.freeze
    end
  end

-  Template.register_tag('for', For)
+  Template.register_tag('for'.freeze, For)
 end
--- a/lib/liquid/tags/if.rb
+++ b/lib/liquid/tags/if.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  # If is the conditional block
  #
@@ -14,18 +12,12 @@ module Liquid
  class If < Block
    Syntax = /(#{QuotedFragment})\s*([=!<>a-z_]+)?\s*(#{QuotedFragment})?/o
    ExpressionsAndOperators = /(?:\b(?:\s?and\s?|\s?or\s?)\b|(?:\s*(?!\b(?:\s?and\s?|\s?or\s?)\b)(?:#{QuotedFragment}|\S+)\s*)+)/o
-    BOOLEAN_OPERATORS = %w(and or).freeze
-
-    attr_reader :blocks
+    BOOLEAN_OPERATORS = %w(and or)

    def initialize(tag_name, markup, options)
      super
      @blocks = []
-      push_block('if', markup)
-    end
-
-    def nodelist
-      @blocks.map(&:attachment)
+      push_block('if'.freeze, markup)
    end

    def parse(tokens)
@@ -33,28 +25,33 @@ module Liquid
      end
    end

+    def nodelist
+      @blocks.map(&:attachment)
+    end
+
    def unknown_tag(tag, markup, tokens)
-      if ['elsif', 'else'].include?(tag)
+      if ['elsif'.freeze, 'else'.freeze].include?(tag)
        push_block(tag, markup)
      else
        super
      end
    end

-    def render_to_output_buffer(context, output)
-      @blocks.each do |block|
-        if block.evaluate(context)
-          return block.attachment.render_to_output_buffer(context, output)
+    def render(context)
+      context.stack do
+        @blocks.each do |block|
+          if block.evaluate(context)
+            return block.attachment.render(context)
+          end
        end
+        ''.freeze
      end
-
-      output
    end

    private

    def push_block(tag, markup)
-      block = if tag == 'else'
+      block = if tag == 'else'.freeze
        ElseCondition.new
      else
        parse_with_selected_parser(markup)
@@ -66,17 +63,17 @@ module Liquid

    def lax_parse(markup)
      expressions = markup.scan(ExpressionsAndOperators)
-      raise SyntaxError, options[:locale].t("errors.syntax.if") unless expressions.pop =~ Syntax
+      raise(SyntaxError.new(options[:locale].t("errors.syntax.if".freeze))) unless expressions.pop =~ Syntax

-      condition = Condition.new(Expression.parse(Regexp.last_match(1)), Regexp.last_match(2), Expression.parse(Regexp.last_match(3)))
+      condition = Condition.new(Expression.parse($1), $2, Expression.parse($3))

      until expressions.empty?
        operator = expressions.pop.to_s.strip

-        raise SyntaxError, options[:locale].t("errors.syntax.if") unless expressions.pop.to_s =~ Syntax
+        raise(SyntaxError.new(options[:locale].t("errors.syntax.if".freeze))) unless expressions.pop.to_s =~ Syntax

-        new_condition = Condition.new(Expression.parse(Regexp.last_match(1)), Regexp.last_match(2), Expression.parse(Regexp.last_match(3)))
-        raise SyntaxError, options[:locale].t("errors.syntax.if") unless BOOLEAN_OPERATORS.include?(operator)
+        new_condition = Condition.new(Expression.parse($1), $2, Expression.parse($3))
+        raise(SyntaxError.new(options[:locale].t("errors.syntax.if".freeze))) unless BOOLEAN_OPERATORS.include?(operator)
        new_condition.send(operator, condition)
        condition = new_condition
      end
@@ -94,7 +91,7 @@ module Liquid
    def parse_binary_comparisons(p)
      condition = parse_comparison(p)
      first_condition = condition
-      while (op = (p.id?('and') || p.id?('or')))
+      while op = (p.id?('and'.freeze) || p.id?('or'.freeze))
        child_condition = parse_comparison(p)
        condition.send(op, child_condition)
        condition = child_condition
@@ -104,20 +101,14 @@ module Liquid

    def parse_comparison(p)
      a = Expression.parse(p.expression)
-      if (op = p.consume?(:comparison))
+      if op = p.consume?(:comparison)
        b = Expression.parse(p.expression)
        Condition.new(a, op, b)
      else
        Condition.new(a)
      end
    end
-
-    class ParseTreeVisitor < Liquid::ParseTreeVisitor
-      def children
-        @node.blocks
-      end
-    end
  end

-  Template.register_tag('if', If)
+  Template.register_tag('if'.freeze, If)
 end
--- a/lib/liquid/tags/ifchanged.rb
+++ b/lib/liquid/tags/ifchanged.rb
@@ -1,19 +1,18 @@
-# frozen_string_literal: true
-
 module Liquid
  class Ifchanged < Block
-    def render_to_output_buffer(context, output)
-      block_output = +''
-      super(context, block_output)
+    def render(context)
+      context.stack do
+        output = super

-      if block_output != context.registers[:ifchanged]
-        context.registers[:ifchanged] = block_output
-        output << block_output
+        if output != context.registers[:ifchanged]
+          context.registers[:ifchanged] = output
+          output
+        else
+          ''.freeze
+        end
      end
-
-      output
    end
  end

-  Template.register_tag('ifchanged', Ifchanged)
+  Template.register_tag('ifchanged'.freeze, Ifchanged)
 end
--- a/lib/liquid/tags/include.rb
+++ b/lib/liquid/tags/include.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  # Include allows templates to relate with other templates
  #
@@ -18,15 +16,13 @@ module Liquid
  class Include < Tag
    Syntax = /(#{QuotedFragment}+)(\s+(?:with|for)\s+(#{QuotedFragment}+))?/o

-    attr_reader :template_name_expr, :variable_name_expr, :attributes
-
    def initialize(tag_name, markup, options)
      super

      if markup =~ Syntax

-        template_name = Regexp.last_match(1)
-        variable_name = Regexp.last_match(3)
+        template_name = $1
+        variable_name = $3

        @variable_name_expr = variable_name ? Expression.parse(variable_name) : nil
        @template_name_expr = Expression.parse(template_name)
@@ -37,24 +33,19 @@ module Liquid
        end

      else
-        raise SyntaxError, options[:locale].t("errors.syntax.include")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.include".freeze))
      end
    end

    def parse(_tokens)
    end

-    def render_to_output_buffer(context, output)
+    def render(context)
      template_name = context.evaluate(@template_name_expr)
-      raise ArgumentError, options[:locale].t("errors.argument.include") unless template_name
+      raise ArgumentError.new(options[:locale].t("errors.argument.include")) unless template_name

-      partial = PartialCache.load(
-        template_name,
-        context: context,
-        parse_context: parse_context
-      )
-
-      context_variable_name = template_name.split('/').last
+      partial = load_cached_partial(template_name, context)
+      context_variable_name = template_name.split('/'.freeze).last

      variable = if @variable_name_expr
        context.evaluate(@variable_name_expr)
@@ -73,35 +64,50 @@ module Liquid
          end

          if variable.is_a?(Array)
-            variable.each do |var|
+            variable.collect do |var|
              context[context_variable_name] = var
-              partial.render_to_output_buffer(context, output)
+              partial.render(context)
            end
          else
            context[context_variable_name] = variable
-            partial.render_to_output_buffer(context, output)
+            partial.render(context)
          end
        end
      ensure
        context.template_name = old_template_name
        context.partial = old_partial
      end
-
-      output
    end

+    private
+
    alias_method :parse_context, :options
    private :parse_context

-    class ParseTreeVisitor < Liquid::ParseTreeVisitor
-      def children
-        [
-          @node.template_name_expr,
-          @node.variable_name_expr,
-        ] + @node.attributes.values
+    def load_cached_partial(template_name, context)
+      cached_partials = context.registers[:cached_partials] || {}
+
+      if cached = cached_partials[template_name]
+        return cached
      end
+      source = read_template_from_file_system(context)
+      begin
+        parse_context.partial = true
+        partial = Liquid::Template.parse(source, parse_context)
+      ensure
+        parse_context.partial = false
+      end
+      cached_partials[template_name] = partial
+      context.registers[:cached_partials] = cached_partials
+      partial
+    end
+
+    def read_template_from_file_system(context)
+      file_system = context.registers[:file_system] || Liquid::Template.file_system
+
+      file_system.read_template_file(context.evaluate(@template_name_expr))
    end
  end

-  Template.register_tag('include', Include)
+  Template.register_tag('include'.freeze, Include)
 end
--- a/lib/liquid/tags/increment.rb
+++ b/lib/liquid/tags/increment.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  # increment is used in a place where one needs to insert a counter
  #     into a template, and needs the counter to survive across
@@ -22,14 +20,12 @@ module Liquid
      @variable = markup.strip
    end

-    def render_to_output_buffer(context, output)
+    def render(context)
      value = context.environments.first[@variable] ||= 0
      context.environments.first[@variable] = value + 1
-
-      output << value.to_s
-      output
+      value.to_s
    end
  end

-  Template.register_tag('increment', Increment)
+  Template.register_tag('increment'.freeze, Increment)
 end
--- a/lib/liquid/tags/raw.rb
+++ b/lib/liquid/tags/raw.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  class Raw < Block
    Syntax = /\A\s*\z/
@@ -12,21 +10,20 @@ module Liquid
    end

    def parse(tokens)
-      @body = +''
-      while (token = tokens.shift)
+      @body = ''
+      while token = tokens.shift
        if token =~ FullTokenPossiblyInvalid
-          @body << Regexp.last_match(1) if Regexp.last_match(1) != ""
-          return if block_delimiter == Regexp.last_match(2)
+          @body << $1 if $1 != "".freeze
+          return if block_delimiter == $2
        end
        @body << token unless token.empty?
      end

-      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed", block_name: block_name)
+      raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_never_closed".freeze, block_name: block_name))
    end

-    def render_to_output_buffer(_context, output)
-      output << @body
-      output
+    def render(_context)
+      @body
    end

    def nodelist
@@ -40,11 +37,11 @@ module Liquid
    protected

    def ensure_valid_markup(tag_name, markup, parse_context)
-      unless Syntax.match?(markup)
-        raise SyntaxError, parse_context.locale.t("errors.syntax.tag_unexpected_args", tag: tag_name)
+      unless markup =~ Syntax
+        raise SyntaxError.new(parse_context.locale.t("errors.syntax.tag_unexpected_args".freeze, tag: tag_name))
      end
    end
  end

-  Template.register_tag('raw', Raw)
+  Template.register_tag('raw'.freeze, Raw)
 end
--- a/lib/liquid/tags/render.rb
+++ b/lib/liquid/tags/render.rb
@@ -1,56 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  class Render < Tag
-    SYNTAX = /(#{QuotedString})#{QuotedFragment}*/o
-
-    attr_reader :template_name_expr, :attributes
-
-    def initialize(tag_name, markup, options)
-      super
-
-      raise SyntaxError, options[:locale].t("errors.syntax.render") unless markup =~ SYNTAX
-
-      template_name = Regexp.last_match(1)
-
-      @template_name_expr = Expression.parse(template_name)
-
-      @attributes = {}
-      markup.scan(TagAttributes) do |key, value|
-        @attributes[key] = Expression.parse(value)
-      end
-    end
-
-    def render_to_output_buffer(context, output)
-      # Though we evaluate this here we will only ever parse it as a string literal.
-      template_name = context.evaluate(@template_name_expr)
-      raise ArgumentError, options[:locale].t("errors.argument.include") unless template_name
-
-      partial = PartialCache.load(
-        template_name,
-        context: context,
-        parse_context: parse_context
-      )
-
-      inner_context = context.new_isolated_subcontext
-      inner_context.template_name = template_name
-      inner_context.partial = true
-      @attributes.each do |key, value|
-        inner_context[key] = context.evaluate(value)
-      end
-      partial.render_to_output_buffer(inner_context, output)
-
-      output
-    end
-
-    class ParseTreeVisitor < Liquid::ParseTreeVisitor
-      def children
-        [
-          @node.template_name_expr,
-        ] + @node.attributes.values
-      end
-    end
-  end
-
-  Template.register_tag('render', Render)
-end
--- a/lib/liquid/tags/table_row.rb
+++ b/lib/liquid/tags/table_row.rb
@@ -1,67 +1,54 @@
-# frozen_string_literal: true
-
 module Liquid
  class TableRow < Block
    Syntax = /(\w+)\s+in\s+(#{QuotedFragment}+)/o

-    attr_reader :variable_name, :collection_name, :attributes
-
    def initialize(tag_name, markup, options)
      super
      if markup =~ Syntax
-        @variable_name = Regexp.last_match(1)
-        @collection_name = Expression.parse(Regexp.last_match(2))
+        @variable_name = $1
+        @collection_name = Expression.parse($2)
        @attributes = {}
        markup.scan(TagAttributes) do |key, value|
          @attributes[key] = Expression.parse(value)
        end
      else
-        raise SyntaxError, options[:locale].t("errors.syntax.table_row")
+        raise SyntaxError.new(options[:locale].t("errors.syntax.table_row".freeze))
      end
    end

-    def render_to_output_buffer(context, output)
-      (collection = context.evaluate(@collection_name)) || (return '')
+    def render(context)
+      collection = context.evaluate(@collection_name) or return ''.freeze

-      from = @attributes.key?('offset') ? context.evaluate(@attributes['offset']).to_i : 0
-      to = @attributes.key?('limit') ? from + context.evaluate(@attributes['limit']).to_i : nil
+      from = @attributes.key?('offset'.freeze) ? context.evaluate(@attributes['offset'.freeze]).to_i : 0
+      to = @attributes.key?('limit'.freeze) ? from + context.evaluate(@attributes['limit'.freeze]).to_i : nil

      collection = Utils.slice_collection(collection, from, to)

      length = collection.length

-      cols = context.evaluate(@attributes['cols']).to_i
+      cols = context.evaluate(@attributes['cols'.freeze]).to_i

-      output << "<tr class=\"row1\">\n"
+      result = "<tr class=\"row1\">\n"
      context.stack do
        tablerowloop = Liquid::TablerowloopDrop.new(length, cols)
-        context['tablerowloop'] = tablerowloop
+        context['tablerowloop'.freeze] = tablerowloop

-        collection.each do |item|
+        collection.each_with_index do |item, index|
          context[@variable_name] = item

-          output << "<td class=\"col#{tablerowloop.col}\">"
-          super
-          output << '</td>'
+          result << "<td class=\"col#{tablerowloop.col}\">" << super << '</td>'

          if tablerowloop.col_last && !tablerowloop.last
-            output << "</tr>\n<tr class=\"row#{tablerowloop.row + 1}\">"
+            result << "</tr>\n<tr class=\"row#{tablerowloop.row + 1}\">"
          end

          tablerowloop.send(:increment!)
        end
      end
-
-      output << "</tr>\n"
-      output
-    end
-
-    class ParseTreeVisitor < Liquid::ParseTreeVisitor
-      def children
-        super + @node.attributes.values + [@node.collection_name]
-      end
+      result << "</tr>\n"
+      result
    end
  end

-  Template.register_tag('tablerow', TableRow)
+  Template.register_tag('tablerow'.freeze, TableRow)
 end
--- a/lib/liquid/tags/unless.rb
+++ b/lib/liquid/tags/unless.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require_relative 'if'

 module Liquid
@@ -8,23 +6,25 @@ module Liquid
  #   {% unless x < 0 %} x is greater than zero {% endunless %}
  #
  class Unless < If
-    def render_to_output_buffer(context, output)
-      # First condition is interpreted backwards ( if not )
-      first_block = @blocks.first
-      unless first_block.evaluate(context)
-        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)
+    def render(context)
+      context.stack do
+        # First condition is interpreted backwards ( if not )
+        first_block = @blocks.first
+        unless first_block.evaluate(context)
+          return first_block.attachment.render(context)
        end
-      end

-      output
+        # After the first condition unless works just like if
+        @blocks[1..-1].each do |block|
+          if block.evaluate(context)
+            return block.attachment.render(context)
+          end
+        end
+
+        ''.freeze
+      end
    end
  end

-  Template.register_tag('unless', Unless)
+  Template.register_tag('unless'.freeze, Unless)
 end
--- a/lib/liquid/template.rb
+++ b/lib/liquid/template.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  # Templates are central to liquid.
  # Interpretating templates is a two step process. First you compile the
@@ -52,7 +50,7 @@ module Liquid
      private

      def lookup_class(name)
-        Object.const_get(name)
+        name.split("::").reject(&:empty?).reduce(Object) { |scope, const| scope.const_get(const) }
      end
    end

@@ -167,14 +165,14 @@ module Liquid
    #    filters and tags and might be useful to integrate liquid more with its host application
    #
    def render(*args)
-      return '' if @root.nil?
+      return ''.freeze if @root.nil?

      context = case args.first
      when Liquid::Context
        c = args.shift

        if @rethrow_errors
-          c.exception_renderer = ->(_e) { raise }
+          c.exception_renderer = ->(e) { raise }
        end

        c
@@ -189,12 +187,9 @@ module Liquid
        raise ArgumentError, "Expected Hash or Liquid::Context as parameter"
      end

-      output = nil
-
      case args.last
      when Hash
        options = args.pop
-        output = options[:output] if options[:output]

        registers.merge!(options[:registers]) if options[:registers].is_a?(Hash)

@@ -209,9 +204,10 @@ module Liquid
      begin
        # render the nodelist.
        # for performance reasons we get an array back here. join will make a string out of it.
-        with_profiling(context) do
-          @root.render_to_output_buffer(context, output || +'')
+        result = with_profiling(context) do
+          @root.render(context)
        end
+        result.respond_to?(:join) ? result.join : result
      rescue Liquid::MemoryError => e
        context.handle_error(e)
      ensure
@@ -224,10 +220,6 @@ module Liquid
      render(*args)
    end

-    def render_to_output_buffer(context, output)
-      render(context, output: output)
-    end
-
    private

    def tokenize(source)
--- a/lib/liquid/tokenizer.rb
+++ b/lib/liquid/tokenizer.rb
@@ -1,37 +1,29 @@
-# frozen_string_literal: true
-
 module Liquid
  class Tokenizer
-    attr_reader :line_number, :for_liquid_tag
+    attr_reader :line_number

-    def initialize(source, line_numbers = false, line_number: nil, for_liquid_tag: false)
+    def initialize(source, line_numbers = false)
      @source = source
-      @line_number = line_number || (line_numbers ? 1 : nil)
-      @for_liquid_tag = for_liquid_tag
+      @line_number = line_numbers ? 1 : nil
      @tokens = tokenize
    end

    def shift
-      (token = @tokens.shift) || return
-
-      if @line_number
-        @line_number += @for_liquid_tag ? 1 : token.count("\n")
-      end
-
+      token = @tokens.shift
+      @line_number += token.count("\n") if @line_number && token
      token
    end

    private

    def tokenize
+      @source = @source.source if @source.respond_to?(:source)
      return [] if @source.to_s.empty?

-      return @source.split("\n") if @for_liquid_tag
-
      tokens = @source.split(TemplateParser)

      # removes the rogue empty element at the beginning of the array
-      tokens.shift if tokens[0]&.empty?
+      tokens.shift if tokens[0] && tokens[0].empty?

      tokens
    end
--- a/lib/liquid/usage.rb
+++ b/lib/liquid/usage.rb
@@ -1,8 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  module Usage
-    def self.increment(name)
-    end
-  end
-end
--- a/lib/liquid/utils.rb
+++ b/lib/liquid/utils.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  module Utils
    def self.slice_collection(collection, from, to)
@@ -48,11 +46,11 @@ module Liquid
    def self.to_number(obj)
      case obj
      when Float
-        BigDecimal(obj.to_s)
+        BigDecimal.new(obj.to_s)
      when Numeric
        obj
      when String
-        /\A-?\d+\.\d+\z/.match?(obj.strip) ? BigDecimal(obj) : obj.to_i
+        (obj.strip =~ /\A-?\d+\.\d+\z/) ? BigDecimal.new(obj) : obj.to_i
      else
        if obj.respond_to?(:to_number)
          obj.to_number
@@ -71,7 +69,7 @@ module Liquid
      end

      case obj
-      when 'now', 'today'
+      when 'now'.freeze, 'today'.freeze
        Time.now
      when /\A\d+\z/, Integer
        Time.at(obj.to_i)
--- a/lib/liquid/variable.rb
+++ b/lib/liquid/variable.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module Liquid
  # Holds variables. Variables are only loaded "just in time"
  # and are not evaluated as part of the render stage
@@ -12,16 +10,10 @@ module Liquid
  #   {{ user | link }}
  #
  class Variable
-    FilterMarkupRegex = /#{FilterSeparator}\s*(.*)/om
    FilterParser = /(?:\s+|#{QuotedFragment}|#{ArgumentSeparator})+/o
-    FilterArgsRegex = /(?:#{FilterArgumentSeparator}|#{ArgumentSeparator})\s*((?:\w+\s*\:\s*)?#{QuotedFragment})/o
-    JustTagAttributes = /\A#{TagAttributes}\z/o
-    MarkupWithQuotedFragment = /(#{QuotedFragment})(.*)/om
-
    attr_accessor :filters, :name, :line_number
    attr_reader :parse_context
    alias_method :options, :parse_context
-
    include ParserSwitching

    def initialize(markup, parse_context)
@@ -43,17 +35,17 @@ module Liquid

    def lax_parse(markup)
      @filters = []
-      return unless markup =~ MarkupWithQuotedFragment
+      return unless markup =~ /(#{QuotedFragment})(.*)/om

-      name_markup = Regexp.last_match(1)
-      filter_markup = Regexp.last_match(2)
+      name_markup = $1
+      filter_markup = $2
      @name = Expression.parse(name_markup)
-      if filter_markup =~ FilterMarkupRegex
-        filters = Regexp.last_match(1).scan(FilterParser)
+      if filter_markup =~ /#{FilterSeparator}\s*(.*)/om
+        filters = $1.scan(FilterParser)
        filters.each do |f|
          next unless f =~ /\w+/
          filtername = Regexp.last_match(0)
-          filterargs = f.scan(FilterArgsRegex).flatten
+          filterargs = f.scan(/(?:#{FilterArgumentSeparator}|#{ArgumentSeparator})\s*((?:\w+\s*\:\s*)?#{QuotedFragment})/o).flatten
          @filters << parse_filter_expressions(filtername, filterargs)
        end
      end
@@ -87,43 +79,31 @@ module Liquid
      end

      obj = context.apply_global_filter(obj)
+
      taint_check(context, obj)
+
      obj
    end

-    def render_to_output_buffer(context, output)
-      obj = render(context)
-
-      if obj.is_a?(Array)
-        output << obj.join
-      elsif obj.nil?
-      else
-        output << obj.to_s
-      end
-
-      output
-    end
-
    private

    def parse_filter_expressions(filter_name, unparsed_args)
      filter_args = []
-      keyword_args = nil
+      keyword_args = {}
      unparsed_args.each do |a|
-        if (matches = a.match(JustTagAttributes))
-          keyword_args ||= {}
+        if matches = a.match(/\A#{TagAttributes}\z/o)
          keyword_args[matches[1]] = Expression.parse(matches[2])
        else
          filter_args << Expression.parse(a)
        end
      end
      result = [filter_name, filter_args]
-      result << keyword_args if keyword_args
+      result << keyword_args unless keyword_args.empty?
      result
    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|
@@ -152,11 +132,5 @@ module Liquid
        raise error
      end
    end
-
-    class ParseTreeVisitor < Liquid::ParseTreeVisitor
-      def children
-        [@node.name] + @node.filters.flatten
-      end
-    end
  end
 end
--- a/lib/liquid/variable_lookup.rb
+++ b/lib/liquid/variable_lookup.rb
@@ -1,9 +1,7 @@
-# frozen_string_literal: true
-
 module Liquid
  class VariableLookup
    SQUARE_BRACKETED = /\A\[(.*)\]\z/m
-    COMMAND_METHODS = ['size', 'first', 'last'].freeze
+    COMMAND_METHODS = ['size'.freeze, 'first'.freeze, 'last'.freeze]

    attr_reader :name, :lookups

@@ -16,7 +14,7 @@ module Liquid

      name = lookups.shift
      if name =~ SQUARE_BRACKETED
-        name = Expression.parse(Regexp.last_match(1))
+        name = Expression.parse($1)
      end
      @name = name

@@ -26,7 +24,7 @@ module Liquid
      @lookups.each_index do |i|
        lookup = lookups[i]
        if lookup =~ SQUARE_BRACKETED
-          lookups[i] = Expression.parse(Regexp.last_match(1))
+          lookups[i] = Expression.parse($1)
        elsif COMMAND_METHODS.include?(lookup)
          @command_flags |= 1 << i
        end
@@ -80,11 +78,5 @@ module Liquid
    def state
      [@name, @lookups, @command_flags]
    end
-
-    class ParseTreeVisitor < Liquid::ParseTreeVisitor
-      def children
-        @node.lookups
-      end
-    end
  end
 end
--- a/lib/liquid/version.rb
+++ b/lib/liquid/version.rb
@@ -1,6 +1,4 @@
 # encoding: utf-8
-# frozen_string_literal: true
-
 module Liquid
-  VERSION = "4.0.3"
+  VERSION = "4.0.0"
 end
--- a/liquid.gemspec
+++ b/liquid.gemspec
@@ -1,8 +1,6 @@
 # encoding: utf-8
-# frozen_string_literal: true
-
 lib = File.expand_path('../lib/', __FILE__)
-$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
+$LOAD_PATH.unshift lib unless $LOAD_PATH.include?(lib)

 require "liquid/version"

@@ -17,7 +15,7 @@ Gem::Specification.new do |s|
  s.license     = "MIT"
  # s.description = "A secure, non-evaling end user template engine with aesthetic markup."

-  s.required_ruby_version     = ">= 2.4.0"
+  s.required_ruby_version     = ">= 2.1.0"
  s.required_rubygems_version = ">= 1.3.7"

  s.test_files  = Dir.glob("{test}/**/*")
@@ -27,6 +25,6 @@ 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
--- a/performance/benchmark.rb
+++ b/performance/benchmark.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'benchmark/ips'
 require_relative 'theme_runner'

--- a/performance/memory_profile.rb
+++ b/performance/memory_profile.rb
@@ -1,63 +0,0 @@
-# frozen_string_literal: true
-
-require 'benchmark/ips'
-require 'memory_profiler'
-require 'terminal-table'
-require_relative 'theme_runner'
-
-class Profiler
-  LOG_LABEL   = "Profiling: ".rjust(14).freeze
-  REPORTS_DIR = File.expand_path('.memprof', __dir__).freeze
-
-  def self.run
-    puts
-    yield new
-  end
-
-  def initialize
-    @allocated = []
-    @retained  = []
-    @headings  = []
-  end
-
-  def profile(phase, &block)
-    print LOG_LABEL
-    print "#{phase}.. ".ljust(10)
-    report = MemoryProfiler.report(&block)
-    puts 'Done.'
-    @headings  << phase.capitalize
-    @allocated << "#{report.scale_bytes(report.total_allocated_memsize)} (#{report.total_allocated} objects)"
-    @retained  << "#{report.scale_bytes(report.total_retained_memsize)} (#{report.total_retained} objects)"
-
-    return if ENV['CI']
-
-    require 'fileutils'
-    report_file = File.join(REPORTS_DIR, "#{sanitize(phase)}.txt")
-    FileUtils.mkdir_p(REPORTS_DIR)
-    report.pretty_print(to_file: report_file, scale_bytes: true)
-  end
-
-  def tabulate
-    table = Terminal::Table.new(headings: @headings.unshift('Phase')) do |t|
-      t << @allocated.unshift('Total allocated')
-      t << @retained.unshift('Total retained')
-    end
-
-    puts
-    puts table
-    puts "\nDetailed report(s) saved to #{REPORTS_DIR}/" unless ENV['CI']
-  end
-
-  def sanitize(string)
-    string.downcase.gsub(/[\W]/, '-').squeeze('-')
-  end
-end
-
-Liquid::Template.error_mode = ARGV.first.to_sym if ARGV.first
-
-runner = ThemeRunner.new
-Profiler.run do |x|
-  x.profile('parse') { runner.compile }
-  x.profile('render') { runner.render }
-  x.tabulate
-end
--- a/performance/profile.rb
+++ b/performance/profile.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'stackprof'
 require_relative 'theme_runner'

@@ -15,7 +13,7 @@ profiler.run
    end
  end

-  if profile_type == :cpu && (graph_filename = ENV['GRAPH_FILENAME'])
+  if profile_type == :cpu && graph_filename = ENV['GRAPH_FILENAME']
    File.open(graph_filename, 'w') do |f|
      StackProf::Report.new(results).print_graphviz(nil, f)
    end
--- a/performance/shopify/comment_form.rb
+++ b/performance/shopify/comment_form.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 class CommentForm < Liquid::Block
  Syntax = /(#{Liquid::VariableSignature}+)/

@@ -7,14 +5,14 @@ class CommentForm < Liquid::Block
    super

    if markup =~ Syntax
-      @variable_name = Regexp.last_match(1)
+      @variable_name = $1
      @attributes = {}
    else
-      raise SyntaxError, "Syntax Error in 'comment_form' - Valid syntax: comment_form [article]"
+      raise SyntaxError.new("Syntax Error in 'comment_form' - Valid syntax: comment_form [article]")
    end
  end

-  def render_to_output_buffer(context, output)
+  def render(context)
    article = context[@variable_name]

    context.stack do
@@ -22,12 +20,10 @@ 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))
-      output
+      wrap_in_form(article, render_all(@nodelist, context))
    end
  end

--- a/performance/shopify/database.rb
+++ b/performance/shopify/database.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'yaml'

 module Database
@@ -18,10 +16,9 @@ module Database
      end

      # key the tables by handles, as this is how liquid expects it.
-      db = db.each_with_object({}) do |(key, values), assigns|
-        assigns[key] = values.each_with_object({}) do |v, h|
-          h[v['handle']] = v
-        end
+      db = db.inject({}) do |assigns, (key, values)|
+        assigns[key] = values.inject({}) { |h, v| h[v['handle']] = v; h; }
+        assigns
      end

      # Some standard direct accessors so that the specialized templates
@@ -32,9 +29,9 @@ module Database
      db['article']    = db['blog']['articles'].first

      db['cart']       = {
-        'total_price' => db['line_items'].values.inject(0) { |sum, item| sum + item['line_price'] * item['quantity'] },
-        'item_count' => db['line_items'].values.inject(0) { |sum, item| sum + item['quantity'] },
-        'items' => db['line_items'].values,
+        'total_price' => db['line_items'].values.inject(0) { |sum, item| sum += item['line_price'] * item['quantity'] },
+        'item_count'  => db['line_items'].values.inject(0) { |sum, item| sum += item['quantity'] },
+        'items'       => db['line_items'].values
      }

      db
@@ -43,6 +40,6 @@ module Database
 end

 if __FILE__ == $PROGRAM_NAME
-  p(Database.tables['collections']['frontpage'].keys)
+  p Database.tables['collections']['frontpage'].keys
  # p Database.tables['blog']['articles']
 end
--- a/performance/shopify/json_filter.rb
+++ b/performance/shopify/json_filter.rb
@@ -1,9 +1,7 @@
-# frozen_string_literal: true
-
 require 'json'

 module JsonFilter
  def json(object)
-    JSON.dump(object.reject { |k, _v| k == "collections" })
+    JSON.dump(object.reject { |k, v| k == "collections" })
  end
 end
--- a/performance/shopify/liquid.rb
+++ b/performance/shopify/liquid.rb
@@ -1,6 +1,4 @@
-# frozen_string_literal: true
-
-$LOAD_PATH.unshift(__dir__ + '/../../lib')
+$:.unshift __dir__ + '/../../lib'
 require_relative '../../lib/liquid'

 require_relative 'comment_form'
@@ -11,11 +9,11 @@ require_relative 'shop_filter'
 require_relative 'tag_filter'
 require_relative 'weight_filter'

-Liquid::Template.register_tag('paginate', Paginate)
-Liquid::Template.register_tag('form', CommentForm)
+Liquid::Template.register_tag 'paginate', Paginate
+Liquid::Template.register_tag 'form', CommentForm

-Liquid::Template.register_filter(JsonFilter)
-Liquid::Template.register_filter(MoneyFilter)
-Liquid::Template.register_filter(WeightFilter)
-Liquid::Template.register_filter(ShopFilter)
-Liquid::Template.register_filter(TagFilter)
+Liquid::Template.register_filter JsonFilter
+Liquid::Template.register_filter MoneyFilter
+Liquid::Template.register_filter WeightFilter
+Liquid::Template.register_filter ShopFilter
+Liquid::Template.register_filter TagFilter
--- a/performance/shopify/money_filter.rb
+++ b/performance/shopify/money_filter.rb
@@ -1,14 +1,12 @@
-# frozen_string_literal: true
-
 module MoneyFilter
  def money_with_currency(money)
    return '' if money.nil?
-    format("$ %.2f USD", money / 100.0)
+    sprintf("$ %.2f USD", money / 100.0)
  end

  def money(money)
    return '' if money.nil?
-    format("$ %.2f", money / 100.0)
+    sprintf("$ %.2f", money / 100.0)
  end

  private
--- a/performance/shopify/paginate.rb
+++ b/performance/shopify/paginate.rb
@@ -1,15 +1,13 @@
-# frozen_string_literal: true
-
 class Paginate < Liquid::Block
-  Syntax = /(#{Liquid::QuotedFragment})\s*(by\s*(\d+))?/
+  Syntax     = /(#{Liquid::QuotedFragment})\s*(by\s*(\d+))?/

  def initialize(tag_name, markup, options)
    super

    if markup =~ Syntax
-      @collection_name = Regexp.last_match(1)
-      @page_size = if Regexp.last_match(2)
-        Regexp.last_match(3).to_i
+      @collection_name = $1
+      @page_size = if $2
+        $3.to_i
      else
        20
      end
@@ -19,27 +17,27 @@ class Paginate < Liquid::Block
        @attributes[key] = value
      end
    else
-      raise SyntaxError, "Syntax Error in tag 'paginate' - Valid syntax: paginate [collection] by number"
+      raise SyntaxError.new("Syntax Error in tag 'paginate' - Valid syntax: paginate [collection] by number")
    end
  end

-  def render_to_output_buffer(context, output)
+  def render(context)
    @context = context

    context.stack do
-      current_page = context['current_page'].to_i
+      current_page  = context['current_page'].to_i

      pagination = {
-        'page_size' => @page_size,
-        'current_page' => 5,
-        'current_offset' => @page_size * 5,
+        'page_size'      => @page_size,
+        'current_page'   => 5,
+        'current_offset' => @page_size * 5
      }

      context['paginate'] = pagination

-      collection_size = context[@collection_name].size
+      collection_size  = context[@collection_name].size

-      raise ArgumentError, "Cannot paginate array '#{@collection_name}'. Not found." if collection_size.nil?
+      raise ArgumentError.new("Cannot paginate array '#{@collection_name}'. Not found.") if collection_size.nil?

      page_count = (collection_size.to_f / @page_size.to_f).to_f.ceil + 1

--- a/performance/shopify/shop_filter.rb
+++ b/performance/shopify/shop_filter.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module ShopFilter
  def asset_url(input)
    "/files/1/[shop_id]/[shop_id]/assets/#{input}"
@@ -54,7 +52,7 @@ module ShopFilter
  end

  def product_img_url(url, style = 'small')
-    unless url =~ %r{\Aproducts/([\w\-\_]+)\.(\w{2,4})}
+    unless url =~ /\Aproducts\/([\w\-\_]+)\.(\w{2,4})/
      raise ArgumentError, 'filter "size" can only be called on product images'
    end

@@ -62,7 +60,7 @@ module ShopFilter
    when 'original'
      return '/files/shops/random_number/' + url
    when 'grande', 'large', 'medium', 'compact', 'small', 'thumb', 'icon'
-      "/files/shops/random_number/products/#{Regexp.last_match(1)}_#{style}.#{Regexp.last_match(2)}"
+      "/files/shops/random_number/products/#{$1}_#{style}.#{$2}"
    else
      raise ArgumentError, 'valid parameters for filter "size" are: original, grande, large, medium, compact, small, thumb and icon '
    end
@@ -72,14 +70,16 @@ module ShopFilter
    html = []
    html << %(<span class="prev">#{link_to(paginate['previous']['title'], paginate['previous']['url'])}</span>) if paginate['previous']

-    paginate['parts'].each do |part|
-      html << if part['is_link']
-        %(<span class="page">#{link_to(part['title'], part['url'])}</span>)
+    for part in paginate['parts']
+
+      if part['is_link']
+        html << %(<span class="page">#{link_to(part['title'], part['url'])}</span>)
      elsif part['title'].to_i == paginate['current_page'].to_i
-        %(<span class="page current">#{part['title']}</span>)
+        html << %(<span class="page current">#{part['title']}</span>)
      else
-        %(<span class="deco">#{part['title']}</span>)
+        html << %(<span class="deco">#{part['title']}</span>)
      end
+
    end

    html << %(<span class="next">#{link_to(paginate['next']['title'], paginate['next']['url'])}</span>) if paginate['next']
--- a/performance/shopify/tag_filter.rb
+++ b/performance/shopify/tag_filter.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 module TagFilter
  def link_to_tag(label, tag)
    "<a title=\"Show tag #{tag}\" href=\"/collections/#{@context['handle']}/#{tag}\">#{label}</a>"
@@ -15,11 +13,11 @@ module TagFilter

  def link_to_add_tag(label, tag)
    tags = (@context['current_tags'] + [tag]).uniq
-    "<a title=\"Show tag #{tag}\" href=\"/collections/#{@context['handle']}/#{tags.join('+')}\">#{label}</a>"
+    "<a title=\"Show tag #{tag}\" href=\"/collections/#{@context['handle']}/#{tags.join("+")}\">#{label}</a>"
  end

  def link_to_remove_tag(label, tag)
    tags = (@context['current_tags'] - [tag]).uniq
-    "<a title=\"Show tag #{tag}\" href=\"/collections/#{@context['handle']}/#{tags.join('+')}\">#{label}</a>"
+    "<a title=\"Show tag #{tag}\" href=\"/collections/#{@context['handle']}/#{tags.join("+")}\">#{label}</a>"
  end
 end
--- a/performance/shopify/weight_filter.rb
+++ b/performance/shopify/weight_filter.rb
@@ -1,8 +1,6 @@
-# frozen_string_literal: true
-
 module WeightFilter
  def weight(grams)
-    format("%.2f", grams / 1000)
+    sprintf("%.2f", grams / 1000)
  end

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

--- a/test/integration/assign_test.rb
+++ b/test/integration/assign_test.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'

 class AssignTest < Minitest::Test
--- a/test/integration/blank_test.rb
+++ b/test/integration/blank_test.rb
@@ -1,12 +1,11 @@
-# frozen_string_literal: true
-
 require 'test_helper'

 class FoobarTag < Liquid::Tag
-  def render_to_output_buffer(_context, output)
-    output << ' '
-    output
+  def render(*args)
+    " "
  end
+
+  Liquid::Template.register_tag('foobar', FoobarTag)
 end

 class BlankTestFileSystem
@@ -32,9 +31,7 @@ class BlankTest < Minitest::Test
  end

  def test_new_tags_are_not_blank_by_default
-    with_custom_tag('foobar', FoobarTag) do
-      assert_template_result(" " * N, wrap_in_for("{% foobar %}"))
-    end
+    assert_template_result(" " * N, wrap_in_for("{% foobar %}"))
  end

  def test_loops_are_blank
--- a/test/integration/block_test.rb
+++ b/test/integration/block_test.rb
@@ -1,14 +0,0 @@
-# frozen_string_literal: true
-
-require 'test_helper'
-
-class BlockTest < Minitest::Test
-  include Liquid
-
-  def test_unexpected_end_tag
-    exc = assert_raises(SyntaxError) do
-      Template.parse("{% if true %}{% endunless %}")
-    end
-    assert_equal exc.message, "Liquid syntax error: 'endunless' is not a valid delimiter for if tags. use endif"
-  end
-end
--- a/test/integration/capture_test.rb
+++ b/test/integration/capture_test.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'

 class CaptureTest < Minitest::Test
--- a/test/integration/context_test.rb
+++ b/test/integration/context_test.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'

 class ContextTest < Minitest::Test
--- a/test/integration/document_test.rb
+++ b/test/integration/document_test.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'

 class DocumentTest < Minitest::Test
--- a/test/integration/drop_test.rb
+++ b/test/integration/drop_test.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'

 class ContextDrop < Liquid::Drop
@@ -33,7 +31,7 @@ class ProductDrop < Liquid::Drop

  class CatchallDrop < Liquid::Drop
    def liquid_method_missing(method)
-      "catchall_method: #{method}"
+      'catchall_method: ' << method.to_s
    end
  end

@@ -50,7 +48,7 @@ class ProductDrop < Liquid::Drop
  end

  def user_input
-    (+"foo").taint
+    "foo".taint
  end

  protected
@@ -203,9 +201,9 @@ 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
@@ -243,7 +241,7 @@ class DropsTest < Minitest::Test
  end

  def test_some_enumerable_methods_still_get_invoked
-    [:count, :max].each do |method|
+    [ :count, :max ].each do |method|
      assert_equal "3", Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => RealEnumerableDrop.new)
      assert_equal "3", Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => RealEnumerableDrop.new)
      assert_equal "3", Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => EnumerableDrop.new)
@@ -252,7 +250,7 @@ class DropsTest < Minitest::Test

    assert_equal "yes", Liquid::Template.parse("{% if collection contains 3 %}yes{% endif %}").render!('collection' => RealEnumerableDrop.new)

-    [:min, :first].each do |method|
+    [ :min, :first ].each do |method|
      assert_equal "1", Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => RealEnumerableDrop.new)
      assert_equal "1", Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => RealEnumerableDrop.new)
      assert_equal "1", Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => EnumerableDrop.new)
@@ -272,11 +270,4 @@ class DropsTest < Minitest::Test
    assert_equal 'ProductDrop', Liquid::Template.parse("{{ product }}").render!('product' => ProductDrop.new)
    assert_equal 'EnumerableDrop', Liquid::Template.parse('{{ collection }}').render!('collection' => EnumerableDrop.new)
  end
-
-  def test_invokable_methods
-    assert_equal %w(to_liquid catchall user_input context texts).to_set, ProductDrop.invokable_methods
-    assert_equal %w(to_liquid scopes_as_array loop_pos scopes).to_set, ContextDrop.invokable_methods
-    assert_equal %w(to_liquid size max min first count).to_set, EnumerableDrop.invokable_methods
-    assert_equal %w(to_liquid max min sort count first).to_set, RealEnumerableDrop.invokable_methods
-  end
 end # DropsTest
--- a/test/integration/error_handling_test.rb
+++ b/test/integration/error_handling_test.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'

 class ErrorHandlingTest < Minitest::Test
@@ -85,14 +83,15 @@ class ErrorHandlingTest < Minitest::Test

  def test_with_line_numbers_adds_numbers_to_parser_errors
    err = assert_raises(SyntaxError) do
-      Liquid::Template.parse('
+      Liquid::Template.parse(%q(
          foobar

          {% "cat" | foobar %}

          bla
-        ',
-        line_numbers: true)
+        ),
+        line_numbers: true
+      )
    end

    assert_match(/Liquid syntax error \(line 4\)/, err.message)
@@ -100,14 +99,15 @@ class ErrorHandlingTest < Minitest::Test

  def test_with_line_numbers_adds_numbers_to_parser_errors_with_whitespace_trim
    err = assert_raises(SyntaxError) do
-      Liquid::Template.parse('
+      Liquid::Template.parse(%q(
          foobar

          {%- "cat" | foobar -%}

          bla
-        ',
-        line_numbers: true)
+        ),
+        line_numbers: true
+      )
    end

    assert_match(/Liquid syntax error \(line 4\)/, err.message)
@@ -122,7 +122,8 @@ class ErrorHandlingTest < Minitest::Test
        bla
            ',
      error_mode: :warn,
-      line_numbers: true)
+      line_numbers: true
+                                     )

    assert_equal ['Liquid syntax error (line 4): Unexpected character = in "1 =! 2"'],
      template.warnings.map(&:message)
@@ -138,7 +139,8 @@ class ErrorHandlingTest < Minitest::Test
          bla
                ',
        error_mode: :strict,
-        line_numbers: true)
+        line_numbers: true
+                            )
    end

    assert_equal 'Liquid syntax error (line 4): Unexpected character = in "1 =! 2"', err.message
@@ -155,7 +157,8 @@ class ErrorHandlingTest < Minitest::Test

          bla
                ',
-        line_numbers: true)
+        line_numbers: true
+                            )
    end

    assert_equal "Liquid syntax error (line 5): Unknown tag 'foo'", err.message
@@ -202,7 +205,7 @@ class ErrorHandlingTest < Minitest::Test
  def test_default_exception_renderer_with_internal_error
    template = Liquid::Template.parse('This is a runtime error: {{ errors.runtime_error }}', line_numbers: true)

-    output = template.render('errors' => ErrorDrop.new)
+    output = template.render({ 'errors' => ErrorDrop.new })

    assert_equal 'This is a runtime error: Liquid error (line 1): internal', output
    assert_equal [Liquid::InternalError], template.errors.map(&:class)
@@ -211,13 +214,10 @@ class ErrorHandlingTest < Minitest::Test
  def test_setting_default_exception_renderer
    old_exception_renderer = Liquid::Template.default_exception_renderer
    exceptions = []
-    Liquid::Template.default_exception_renderer = ->(e) {
-      exceptions << e
-      ''
-    }
+    Liquid::Template.default_exception_renderer = ->(e) { exceptions << e; '' }
    template = Liquid::Template.parse('This is a runtime error: {{ errors.argument_error }}')

-    output = template.render('errors' => ErrorDrop.new)
+    output = template.render({ 'errors' => ErrorDrop.new })

    assert_equal 'This is a runtime error: ', output
    assert_equal [Liquid::ArgumentError], template.errors.map(&:class)
@@ -228,10 +228,7 @@ class ErrorHandlingTest < Minitest::Test
  def test_exception_renderer_exposing_non_liquid_error
    template = Liquid::Template.parse('This is a runtime error: {{ errors.runtime_error }}', line_numbers: true)
    exceptions = []
-    handler = ->(e) {
-      exceptions << e
-      e.cause
-    }
+    handler = ->(e) { exceptions << e; e.cause }

    output = template.render({ 'errors' => ErrorDrop.new }, exception_renderer: handler)

@@ -242,7 +239,7 @@ class ErrorHandlingTest < Minitest::Test
  end

  class TestFileSystem
-    def read_template_file(_template_path)
+    def read_template_file(template_path)
      "{{ errors.argument_error }}"
    end
  end
--- a/test/integration/filter_test.rb
+++ b/test/integration/filter_test.rb
@@ -1,26 +1,24 @@
-# frozen_string_literal: true
-
 require 'test_helper'

 module MoneyFilter
  def money(input)
-    format(' %d$ ', input)
+    sprintf(' %d$ ', input)
  end

  def money_with_underscore(input)
-    format(' %d$ ', input)
+    sprintf(' %d$ ', input)
  end
 end

 module CanadianMoneyFilter
  def money(input)
-    format(' %d$ CAD ', input)
+    sprintf(' %d$ CAD ', input)
  end
 end

 module SubstituteFilter
  def substitute(input, params = {})
-    input.gsub(/%\{(\w+)\}/) { |_match| params[Regexp.last_match(1)] }
+    input.gsub(/%\{(\w+)\}/) { |match| params[$1] }
  end
 end

@@ -28,7 +26,7 @@ class FiltersTest < Minitest::Test
  include Liquid

  module OverrideObjectMethodFilter
-    def tap(_input)
+    def tap(input)
      "tap overridden"
    end
  end
@@ -151,7 +149,7 @@ class FiltersTest < Minitest::Test
    assert_equal "tap overridden", Template.parse("{{var | tap}}").render!({ 'var' => 1000 }, filters: [OverrideObjectMethodFilter])

    # tap still treated as a non-existent filter
-    assert_equal "1000", Template.parse("{{var | tap}}").render!('var' => 1000)
+    assert_equal "1000", Template.parse("{{var | tap}}").render!({ 'var' => 1000 })
  end
 end

--- a/test/integration/hash_ordering_test.rb
+++ b/test/integration/hash_ordering_test.rb
@@ -1,17 +1,15 @@
-# frozen_string_literal: true
-
 require 'test_helper'

 class HashOrderingTest < Minitest::Test
  module MoneyFilter
    def money(input)
-      format(' %d$ ', input)
+      sprintf(' %d$ ', input)
    end
  end

  module CanadianMoneyFilter
    def money(input)
-      format(' %d$ CAD ', input)
+      sprintf(' %d$ CAD ', input)
    end
  end

--- a/test/integration/output_test.rb
+++ b/test/integration/output_test.rb
@@ -1,9 +1,7 @@
-# frozen_string_literal: true
-
 require 'test_helper'

 module FunnyFilter
-  def make_funny(_input)
+  def make_funny(input)
    'LOL'
  end

@@ -34,7 +32,7 @@ class OutputTest < Minitest::Test
  def setup
    @assigns = {
      'best_cars' => 'bmw',
-      'car' => { 'bmw' => 'good', 'gm' => 'bad' },
+      'car' => { 'bmw' => 'good', 'gm' => 'bad' }
    }
  end

--- a/test/integration/parse_tree_visitor_test.rb
+++ b/test/integration/parse_tree_visitor_test.rb
@@ -1,247 +0,0 @@
-# frozen_string_literal: true
-
-require 'test_helper'
-
-class ParseTreeVisitorTest < Minitest::Test
-  include Liquid
-
-  def test_variable
-    assert_equal(
-      ["test"],
-      visit(%({{ test }}))
-    )
-  end
-
-  def test_varible_with_filter
-    assert_equal(
-      ["test", "infilter"],
-      visit(%({{ test | split: infilter }}))
-    )
-  end
-
-  def test_dynamic_variable
-    assert_equal(
-      ["test", "inlookup"],
-      visit(%({{ test[inlookup] }}))
-    )
-  end
-
-  def test_if_condition
-    assert_equal(
-      ["test"],
-      visit(%({% if test %}{% endif %}))
-    )
-  end
-
-  def test_complex_if_condition
-    assert_equal(
-      ["test"],
-      visit(%({% if 1 == 1 and 2 == test %}{% endif %}))
-    )
-  end
-
-  def test_if_body
-    assert_equal(
-      ["test"],
-      visit(%({% if 1 == 1 %}{{ test }}{% endif %}))
-    )
-  end
-
-  def test_unless_condition
-    assert_equal(
-      ["test"],
-      visit(%({% unless test %}{% endunless %}))
-    )
-  end
-
-  def test_complex_unless_condition
-    assert_equal(
-      ["test"],
-      visit(%({% unless 1 == 1 and 2 == test %}{% endunless %}))
-    )
-  end
-
-  def test_unless_body
-    assert_equal(
-      ["test"],
-      visit(%({% unless 1 == 1 %}{{ test }}{% endunless %}))
-    )
-  end
-
-  def test_elsif_condition
-    assert_equal(
-      ["test"],
-      visit(%({% if 1 == 1 %}{% elsif test %}{% endif %}))
-    )
-  end
-
-  def test_complex_elsif_condition
-    assert_equal(
-      ["test"],
-      visit(%({% if 1 == 1 %}{% elsif 1 == 1 and 2 == test %}{% endif %}))
-    )
-  end
-
-  def test_elsif_body
-    assert_equal(
-      ["test"],
-      visit(%({% if 1 == 1 %}{% elsif 2 == 2 %}{{ test }}{% endif %}))
-    )
-  end
-
-  def test_else_body
-    assert_equal(
-      ["test"],
-      visit(%({% if 1 == 1 %}{% else %}{{ test }}{% endif %}))
-    )
-  end
-
-  def test_case_left
-    assert_equal(
-      ["test"],
-      visit(%({% case test %}{% endcase %}))
-    )
-  end
-
-  def test_case_condition
-    assert_equal(
-      ["test"],
-      visit(%({% case 1 %}{% when test %}{% endcase %}))
-    )
-  end
-
-  def test_case_when_body
-    assert_equal(
-      ["test"],
-      visit(%({% case 1 %}{% when 2 %}{{ test }}{% endcase %}))
-    )
-  end
-
-  def test_case_else_body
-    assert_equal(
-      ["test"],
-      visit(%({% case 1 %}{% else %}{{ test }}{% endcase %}))
-    )
-  end
-
-  def test_for_in
-    assert_equal(
-      ["test"],
-      visit(%({% for x in test %}{% endfor %}))
-    )
-  end
-
-  def test_for_limit
-    assert_equal(
-      ["test"],
-      visit(%({% for x in (1..5) limit: test %}{% endfor %}))
-    )
-  end
-
-  def test_for_offset
-    assert_equal(
-      ["test"],
-      visit(%({% for x in (1..5) offset: test %}{% endfor %}))
-    )
-  end
-
-  def test_for_body
-    assert_equal(
-      ["test"],
-      visit(%({% for x in (1..5) %}{{ test }}{% endfor %}))
-    )
-  end
-
-  def test_tablerow_in
-    assert_equal(
-      ["test"],
-      visit(%({% tablerow x in test %}{% endtablerow %}))
-    )
-  end
-
-  def test_tablerow_limit
-    assert_equal(
-      ["test"],
-      visit(%({% tablerow x in (1..5) limit: test %}{% endtablerow %}))
-    )
-  end
-
-  def test_tablerow_offset
-    assert_equal(
-      ["test"],
-      visit(%({% tablerow x in (1..5) offset: test %}{% endtablerow %}))
-    )
-  end
-
-  def test_tablerow_body
-    assert_equal(
-      ["test"],
-      visit(%({% tablerow x in (1..5) %}{{ test }}{% endtablerow %}))
-    )
-  end
-
-  def test_cycle
-    assert_equal(
-      ["test"],
-      visit(%({% cycle test %}))
-    )
-  end
-
-  def test_assign
-    assert_equal(
-      ["test"],
-      visit(%({% assign x = test %}))
-    )
-  end
-
-  def test_capture
-    assert_equal(
-      ["test"],
-      visit(%({% capture x %}{{ test }}{% endcapture %}))
-    )
-  end
-
-  def test_include
-    assert_equal(
-      ["test"],
-      visit(%({% include test %}))
-    )
-  end
-
-  def test_include_with
-    assert_equal(
-      ["test"],
-      visit(%({% include "hai" with test %}))
-    )
-  end
-
-  def test_include_for
-    assert_equal(
-      ["test"],
-      visit(%({% include "hai" for test %}))
-    )
-  end
-
-  def test_preserve_tree_structure
-    assert_equal(
-      [[nil, [
-        [nil, [[nil, [["other", []]]]]],
-        ["test", []],
-        ["xs", []],
-      ]]],
-      traversal(%({% for x in xs offset: test %}{{ other }}{% endfor %})).visit
-    )
-  end
-
-  private
-
-  def traversal(template)
-    ParseTreeVisitor
-      .for(Template.parse(template).root)
-      .add_callback_for(VariableLookup, &:name)
-  end
-
-  def visit(template)
-    traversal(template).visit.flatten.compact
-  end
-end
--- a/test/integration/parsing_quirks_test.rb
+++ b/test/integration/parsing_quirks_test.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'

 class ParsingQuirksTest < Minitest::Test
@@ -101,7 +99,7 @@ class ParsingQuirksTest < Minitest::Test
      # After the messed up quotes a filter without parameters (reverse) should work
      # but one with parameters (remove) shouldn't be detected.
      assert_template_result('here',  "{{ 'hi there' | split:\"t\"\" | reverse | first}}")
-      assert_template_result('hi ', "{{ 'hi there' | split:\"t\"\" | remove:\"i\" | first}}")
+      assert_template_result('hi ',  "{{ 'hi there' | split:\"t\"\" | remove:\"i\" | first}}")
    end
  end

--- a/test/integration/render_profiling_test.rb
+++ b/test/integration/render_profiling_test.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'

 class RenderProfilingTest < Minitest::Test
@@ -130,7 +128,7 @@ class RenderProfilingTest < Minitest::Test
    t.render!

    timing_count = 0
-    t.profiler.each do |_timing|
+    t.profiler.each do |timing|
      timing_count += 1
    end

@@ -147,7 +145,7 @@ class RenderProfilingTest < Minitest::Test

  def test_profiling_marks_children_of_for_blocks
    t = Template.parse("{% for item in collection %} {{ item }} {% endfor %}", profile: true)
-    t.render!("collection" => ["one", "two"])
+    t.render!({ "collection" => ["one", "two"] })

    assert_equal 1, t.profiler.length
    # Will profile each invocation of the for block
--- a/test/integration/security_test.rb
+++ b/test/integration/security_test.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'

 module SecurityFilter
--- a/test/integration/standard_filter_test.rb
+++ b/test/integration/standard_filter_test.rb
@@ -1,5 +1,4 @@
 # encoding: utf-8
-# frozen_string_literal: true

 require 'test_helper'

@@ -18,7 +17,7 @@ class TestThing
    "woot: #{@foo}"
  end

-  def [](_whatever)
+  def [](whatever)
    to_s
  end

@@ -38,7 +37,7 @@ class TestEnumerable < Liquid::Drop
  include Enumerable

  def each(&block)
-    [{ "foo" => 1, "bar" => 2 }, { "foo" => 2, "bar" => 1 }, { "foo" => 3, "bar" => 3 }].each(&block)
+    [ { "foo" => 1, "bar" => 2 }, { "foo" => 2, "bar" => 1 }, { "foo" => 3, "bar" => 3 } ].each(&block)
  end
 end

@@ -159,10 +158,6 @@ class StandardFiltersTest < Minitest::Test
    assert_equal '1', @filters.url_decode(1)
    assert_equal '2001-02-03', @filters.url_decode(Date.new(2001, 2, 3))
    assert_nil @filters.url_decode(nil)
-    exception = assert_raises Liquid::ArgumentError do
-      @filters.url_decode('%ff')
-    end
-    assert_equal 'Liquid error: invalid byte sequence in UTF-8', exception.message
  end

  def test_truncatewords
@@ -182,9 +177,6 @@ class StandardFiltersTest < Minitest::Test
    assert_equal 'test', @filters.strip_html("<div\nclass='multiline'>test</div>")
    assert_equal 'test', @filters.strip_html("<!-- foo bar \n test -->test")
    assert_equal '', @filters.strip_html(nil)
-
-    # Quirk of the existing implementation
-    assert_equal 'foo;', @filters.strip_html("<<<script </script>script>foo;</script>")
  end

  def test_join
@@ -198,114 +190,34 @@ class StandardFiltersTest < Minitest::Test
    assert_equal [{ "a" => 1 }, { "a" => 2 }, { "a" => 3 }, { "a" => 4 }], @filters.sort([{ "a" => 4 }, { "a" => 3 }, { "a" => 1 }, { "a" => 2 }], "a")
  end

-  def test_sort_with_nils
-    assert_equal [1, 2, 3, 4, nil], @filters.sort([nil, 4, 3, 2, 1])
-    assert_equal [{ "a" => 1 }, { "a" => 2 }, { "a" => 3 }, { "a" => 4 }, {}], @filters.sort([{ "a" => 4 }, { "a" => 3 }, {}, { "a" => 1 }, { "a" => 2 }], "a")
-  end
-
  def test_sort_when_property_is_sometimes_missing_puts_nils_last
    input = [
      { "price" => 4, "handle" => "alpha" },
      { "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

-  def test_sort_natural
-    assert_equal ["a", "B", "c", "D"], @filters.sort_natural(["c", "D", "a", "B"])
-    assert_equal [{ "a" => "a" }, { "a" => "B" }, { "a" => "c" }, { "a" => "D" }], @filters.sort_natural([{ "a" => "D" }, { "a" => "c" }, { "a" => "a" }, { "a" => "B" }], "a")
-  end
-
-  def test_sort_natural_with_nils
-    assert_equal ["a", "B", "c", "D", nil], @filters.sort_natural([nil, "c", "D", "a", "B"])
-    assert_equal [{ "a" => "a" }, { "a" => "B" }, { "a" => "c" }, { "a" => "D" }, {}], @filters.sort_natural([{ "a" => "D" }, { "a" => "c" }, {}, { "a" => "a" }, { "a" => "B" }], "a")
-  end
-
-  def test_sort_natural_when_property_is_sometimes_missing_puts_nils_last
-    input = [
-      { "price" => "4", "handle" => "alpha" },
-      { "handle" => "beta" },
-      { "price" => "1", "handle" => "gamma" },
-      { "handle" => "delta" },
-      { "price" => 2, "handle" => "epsilon" },
-    ]
-    expectation = [
-      { "price" => "1", "handle" => "gamma" },
-      { "price" => 2, "handle" => "epsilon" },
-      { "price" => "4", "handle" => "alpha" },
-      { "handle" => "delta" },
-      { "handle" => "beta" },
-    ]
-    assert_equal expectation, @filters.sort_natural(input, "price")
-  end
-
-  def test_sort_natural_case_check
-    input = [
-      { "key" => "X" },
-      { "key" => "Y" },
-      { "key" => "Z" },
-      { "fake" => "t" },
-      { "key" => "a" },
-      { "key" => "b" },
-      { "key" => "c" },
-    ]
-    expectation = [
-      { "key" => "a" },
-      { "key" => "b" },
-      { "key" => "c" },
-      { "key" => "X" },
-      { "key" => "Y" },
-      { "key" => "Z" },
-      { "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"])
-  end
-
  def test_sort_empty_array
    assert_equal [], @filters.sort([], "a")
  end

-  def test_sort_invalid_property
-    foo = [
-      [1],
-      [2],
-      [3],
-    ]
-
-    assert_raises Liquid::ArgumentError do
-      @filters.sort(foo, "bar")
-    end
-  end
-
  def test_sort_natural_empty_array
    assert_equal [], @filters.sort_natural([], "a")
  end

-  def test_sort_natural_invalid_property
-    foo = [
-      [1],
-      [2],
-      [3],
-    ]
-
-    assert_raises Liquid::ArgumentError do
-      @filters.sort_natural(foo, "bar")
-    end
-  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
@@ -327,34 +239,10 @@ class StandardFiltersTest < Minitest::Test
    assert_equal [], @filters.uniq([], "a")
  end

-  def test_uniq_invalid_property
-    foo = [
-      [1],
-      [2],
-      [3],
-    ]
-
-    assert_raises Liquid::ArgumentError do
-      @filters.uniq(foo, "bar")
-    end
-  end
-
  def test_compact_empty_array
    assert_equal [], @filters.compact([], "a")
  end

-  def test_compact_invalid_property
-    foo = [
-      [1],
-      [2],
-      [3],
-    ]
-
-    assert_raises Liquid::ArgumentError do
-      @filters.compact(foo, "bar")
-    end
-  end
-
  def test_reverse
    assert_equal [4, 3, 2, 1], @filters.reverse([1, 2, 3, 4])
  end
@@ -381,7 +269,7 @@ class StandardFiltersTest < Minitest::Test

  def test_map_on_hashes
    assert_template_result "4217", '{{ thing | map: "foo" | map: "bar" }}',
-      "thing" => { "foo" => [{ "bar" => 42 }, { "bar" => 17 }] }
+      "thing" => { "foo" => [ { "bar" => 42 }, { "bar" => 17 } ] }
  end

  def test_legacy_map_on_hashes_with_dynamic_key
@@ -398,7 +286,7 @@ class StandardFiltersTest < Minitest::Test

  def test_map_over_proc
    drop = TestDrop.new
-    p = proc { drop }
+    p = proc{ drop }
    templ = '{{ procs | map: "test" }}'
    assert_template_result "testfoo", templ, "procs" => [p]
  end
@@ -406,10 +294,10 @@ class StandardFiltersTest < Minitest::Test
  def test_map_over_drops_returning_procs
    drops = [
      {
-        "proc" => -> { "foo" },
+        "proc" => ->{ "foo" },
      },
      {
-        "proc" => -> { "bar" },
+        "proc" => ->{ "bar" },
      },
    ]
    templ = '{{ drops | map: "proc" }}'
@@ -420,29 +308,6 @@ class StandardFiltersTest < Minitest::Test
    assert_template_result "123", '{{ foo | map: "foo" }}', "foo" => TestEnumerable.new
  end

-  def test_map_returns_empty_on_2d_input_array
-    foo = [
-      [1],
-      [2],
-      [3],
-    ]
-
-    assert_raises Liquid::ArgumentError do
-      @filters.map(foo, "bar")
-    end
-  end
-
-  def test_map_returns_empty_with_no_property
-    foo = [
-      [1],
-      [2],
-      [3],
-    ]
-    assert_raises Liquid::ArgumentError do
-      @filters.map(foo, nil)
-    end
-  end
-
  def test_sort_works_on_enumerables
    assert_template_result "213", '{{ foo | sort: "bar" | map: "foo" }}', "foo" => TestEnumerable.new
  end
@@ -473,9 +338,9 @@ class StandardFiltersTest < Minitest::Test
    assert_equal '07/05/2006', @filters.date("2006-07-05 10:00:00", "%m/%d/%Y")

    assert_equal "07/16/2004", @filters.date("Fri Jul 16 01:00:00 2004", "%m/%d/%Y")
-    assert_equal Date.today.year.to_s, @filters.date('now', '%Y')
-    assert_equal Date.today.year.to_s, @filters.date('today', '%Y')
-    assert_equal Date.today.year.to_s, @filters.date('Today', '%Y')
+    assert_equal "#{Date.today.year}", @filters.date('now', '%Y')
+    assert_equal "#{Date.today.year}", @filters.date('today', '%Y')
+    assert_equal "#{Date.today.year}", @filters.date('Today', '%Y')

    assert_nil @filters.date(nil, "%B")

@@ -631,28 +496,6 @@ class StandardFiltersTest < Minitest::Test
    assert_template_result "5", "{{ price | floor }}", 'price' => NumberLikeThing.new(5.4)
  end

-  def test_at_most
-    assert_template_result "4", "{{ 5 | at_most:4 }}"
-    assert_template_result "5", "{{ 5 | at_most:5 }}"
-    assert_template_result "5", "{{ 5 | at_most:6 }}"
-
-    assert_template_result "4.5", "{{ 4.5 | at_most:5 }}"
-    assert_template_result "5", "{{ width | at_most:5 }}", 'width' => NumberLikeThing.new(6)
-    assert_template_result "4", "{{ width | at_most:5 }}", 'width' => NumberLikeThing.new(4)
-    assert_template_result "4", "{{ 5 | at_most: width }}", 'width' => NumberLikeThing.new(4)
-  end
-
-  def test_at_least
-    assert_template_result "5", "{{ 5 | at_least:4 }}"
-    assert_template_result "5", "{{ 5 | at_least:5 }}"
-    assert_template_result "6", "{{ 5 | at_least:6 }}"
-
-    assert_template_result "5", "{{ 4.5 | at_least:5 }}"
-    assert_template_result "6", "{{ width | at_least:5 }}", 'width' => NumberLikeThing.new(6)
-    assert_template_result "5", "{{ width | at_least:5 }}", 'width' => NumberLikeThing.new(4)
-    assert_template_result "6", "{{ 5 | at_least: width }}", 'width' => NumberLikeThing.new(6)
-  end
-
  def test_append
    assigns = { 'a' => 'bc', 'b' => 'd' }
    assert_template_result('bcd', "{{ a | append: 'd'}}", assigns)
@@ -693,78 +536,6 @@ class StandardFiltersTest < Minitest::Test
    assert_template_result('abc', "{{ 'abc' | date: '%D' }}")
  end

-  def test_where
-    input = [
-      { "handle" => "alpha", "ok" => true },
-      { "handle" => "beta", "ok" => false },
-      { "handle" => "gamma", "ok" => false },
-      { "handle" => "delta", "ok" => true },
-    ]
-
-    expectation = [
-      { "handle" => "alpha", "ok" => true },
-      { "handle" => "delta", "ok" => true },
-    ]
-
-    assert_equal expectation, @filters.where(input, "ok", true)
-    assert_equal expectation, @filters.where(input, "ok")
-  end
-
-  def test_where_no_key_set
-    input = [
-      { "handle" => "alpha", "ok" => true },
-      { "handle" => "beta" },
-      { "handle" => "gamma" },
-      { "handle" => "delta", "ok" => true },
-    ]
-
-    expectation = [
-      { "handle" => "alpha", "ok" => true },
-      { "handle" => "delta", "ok" => true },
-    ]
-
-    assert_equal expectation, @filters.where(input, "ok", true)
-    assert_equal expectation, @filters.where(input, "ok")
-  end
-
-  def test_where_non_array_map_input
-    assert_equal [{ "a" => "ok" }], @filters.where({ "a" => "ok" }, "a", "ok")
-    assert_equal [], @filters.where({ "a" => "not ok" }, "a", "ok")
-  end
-
-  def test_where_indexable_but_non_map_value
-    assert_raises(Liquid::ArgumentError) { @filters.where(1, "ok", true) }
-    assert_raises(Liquid::ArgumentError) { @filters.where(1, "ok") }
-  end
-
-  def test_where_non_boolean_value
-    input = [
-      { "message" => "Bonjour!", "language" => "French" },
-      { "message" => "Hello!", "language" => "English" },
-      { "message" => "Hallo!", "language" => "German" },
-    ]
-
-    assert_equal [{ "message" => "Bonjour!", "language" => "French" }], @filters.where(input, "language", "French")
-    assert_equal [{ "message" => "Hallo!", "language" => "German" }], @filters.where(input, "language", "German")
-    assert_equal [{ "message" => "Hello!", "language" => "English" }], @filters.where(input, "language", "English")
-  end
-
-  def test_where_array_of_only_unindexable_values
-    assert_nil @filters.where([nil], "ok", true)
-    assert_nil @filters.where([nil], "ok")
-  end
-
-  def test_where_no_target_value
-    input = [
-      { "foo" => false },
-      { "foo" => true },
-      { "foo" => "for sure" },
-      { "bar" => true },
-    ]
-
-    assert_equal [{ "foo" => true }, { "foo" => "for sure" }], @filters.where(input, "foo")
-  end
-
  private

  def with_timezone(tz)
--- a/test/integration/tags/break_tag_test.rb
+++ b/test/integration/tags/break_tag_test.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require 'test_helper'

 class BreakTagTest < Minitest::Test
--- a/Show More
+++ b/Show More