Merge pull request #1417 from Shopify/prep-release

Bump to 5.0.1 and add changelog for release

.github/workflows/liquid.yml

@@ -0,0 +1,39 @@
+name: Liquid
+on: [push, pull_request]
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        entry:
+          - { ruby: 2.5, allowed-failure: false } # minimum supported
+          - { ruby: 3.0, allowed-failure: false } # latest
+          - { ruby: ruby-head, allowed-failure: true }
+    name: test (${{ matrix.entry.ruby }})
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.entry.ruby }}
+      - uses: actions/cache@v1
+        with:
+          path: vendor/bundle
+          key: ${{ runner.os }}-gems-${{ hashFiles('Gemfile') }}
+          restore-keys: ${{ runner.os }}-gems-
+      - run: bundle install --jobs=3 --retry=3 --path=vendor/bundle
+      - run: bundle exec rake
+        continue-on-error: ${{ matrix.entry.allowed-failure }}
+  memory_profile:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 2.7
+      - uses: actions/cache@v1
+        with:
+          path: vendor/bundle
+          key: ${{ runner.os }}-gems-${{ hashFiles('Gemfile') }}
+          restore-keys: ${{ runner.os }}-gems-
+      - run: bundle install --jobs=3 --retry=3 --path=vendor/bundle
+      - run: bundle exec rake memory_profile:run

.gitignore

@@ -4,7 +4,6 @@
 pkg
 *.rbc
 .rvmrc
-.idea
 .ruby-version
 Gemfile.lock
 .bundle

.rubocop.yml

@@ -1,10 +1,20 @@
+inherit_gem:
+  rubocop-shopify: rubocop.yml
+
 inherit_from:
-  - .rubocop.shopify.yml
+  - .rubocop_todo.yml
 
 require: rubocop-performance
 
 Performance:
   Enabled: true
 
-Metrics/LineLength:
-  Enabled: false
+AllCops:
+  TargetRubyVersion: 2.4
+  NewCops: disable
+  Exclude:
+    - 'vendor/bundle/**/*'
+
+Naming/MethodName:
+  Exclude:
+    - 'example/server/liquid_servlet.rb'

.rubocop_todo.yml

@@ -0,0 +1,57 @@
+# This configuration was generated by
+# `rubocop --auto-gen-config`
+# on 2020-12-11 18:53:41 UTC using RuboCop version 1.6.1.
+# 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: 113
+# Cop supports --auto-correct.
+# Configuration parameters: AutoCorrect, AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
+# URISchemes: http, https
+Layout/LineLength:
+  Max: 260
+
+# Offense count: 8
+Lint/MissingSuper:
+  Exclude:
+    - 'lib/liquid/forloop_drop.rb'
+    - 'lib/liquid/tablerowloop_drop.rb'
+    - 'test/integration/assign_test.rb'
+    - 'test/integration/context_test.rb'
+    - 'test/integration/filter_test.rb'
+    - 'test/integration/standard_filter_test.rb'
+    - 'test/integration/tags/for_tag_test.rb'
+    - 'test/integration/tags/table_row_test.rb'
+
+# Offense count: 43
+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/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: 2
+Style/ClassVars:
+  Exclude:
+    - 'lib/liquid/condition.rb'

.travis.yml

@@ -1,30 +0,0 @@
-language: ruby
-
-rvm:
-  - 2.4
-  - 2.5
-  - 2.6
-  - 2.7
-  - ruby-head
-  - jruby-head
-  - truffleruby
-
-sudo: false
-
-addons:
-  apt:
-    packages:
-    - libgmp3-dev
-
-matrix:
-  allow_failures:
-    - rvm: ruby-head
-    - rvm: jruby-head
-
-install:
-  - bundle install
-
-script: bundle exec rake
-
-notifications:
-  disable: true

CONTRIBUTING.md

@@ -5,6 +5,7 @@
 * Bugfixes
 * Performance improvements
 * Features that are likely to be useful to the majority of Liquid users
+* Documentation updates that are concise and likely to be useful to the majority of Liquid users
 
 ## Things we won't merge
 
@@ -14,12 +15,14 @@
 * Features that can easily be implemented on top of Liquid (for example as a custom filter or custom filesystem)
 * Code that does not include tests
 * Code that breaks existing tests
+* Documentation changes that are verbose, incorrect or not important to most people (we want to keep it simple and easy to understand)
 
 ## Workflow
 
+* [Sign the CLA](https://cla.shopify.com/) if you haven't already
 * Fork the Liquid repository
 * Create a new branch in your fork
+  * For updating [Liquid documentation](https://shopify.github.io/liquid/), create it from `gh-pages` branch. (You can skip tests.)
 * If it makes sense, add tests for your code and/or run a performance benchmark
 * Make sure all tests pass (`bundle exec rake`)
 * Create a pull request
-

Gemfile

@@ -10,6 +10,7 @@ gemspec
 group :benchmark, :test do
   gem 'benchmark-ips'
   gem 'memory_profiler'
+  gem 'terminal-table'
 
   install_if -> { RUBY_PLATFORM !~ /mingw|mswin|java/ && RUBY_ENGINE != 'truffleruby' } do
     gem 'stackprof'
@@ -17,10 +18,11 @@ group :benchmark, :test do
 end
 
 group :test do
-  gem 'rubocop', '~> 0.74.0', require: false
+  gem 'rubocop', '~> 1.4', require: false
+  gem 'rubocop-shopify', '~> 1.0.7', require: false
   gem 'rubocop-performance', require: false
 
   platform :mri, :truffleruby do
-    gem 'liquid-c', github: 'Shopify/liquid-c', ref: '7ba926791ef8411984d0f3e41c6353fd716041c6'
+    gem 'liquid-c', github: 'Shopify/liquid-c', ref: 'master'
   end
 end

History.md

@@ -1,5 +1,48 @@
 # Liquid Change Log
 
+## 5.0.1 / 2021-03-24
+
+### Fixes
+* Add ParseTreeVisitor to Echo tag (#1414) [CP Clermont]
+* Test with ruby 3.0 as the latest ruby version (#1398) [Dylan Thacker-Smith]
+* Handle carriage return in newlines_to_br (#1391) [Unending]
+
+### Performance Improvements
+* Use split limit in truncatewords (#1361) [Dylan Thacker-Smith]
+
+## 5.0.0 / 2021-01-06
+
+### Features
+* Add new `{% render %}` tag (#1122) [Samuel Doiron]
+* Add support for `as` in `{% render %}` and `{% include %}` (#1181) [Mike Angell]
+* Add `{% liquid %}` and `{% echo %}` tags (#1086) [Justin Li]
+* Add [usage tracking](README.md#usage-tracking) [Mike Angell]
+* Add `Tag.disable_tags` for disabling tags that prepend `Tag::Disableable` at render time (#1162, #1274, #1275) [Mike Angell]
+* Support using a profiler for multiple renders (#1365, #1366) [Dylan Thacker-Smith]
+
+### Fixes
+* Fix catastrophic backtracking in `RANGES_REGEX` regular expression (#1357) [Dylan Thacker-Smith]
+* Make sure the for tag's limit and offset are integers (#1094) [David Cornu]
+* Invokable methods for enumerable reject include (#1151) [Thierry Joyal]
+* Allow `default` filter to handle `false` as value (#1144) [Mike Angell]
+* Fix render length resource limit so it doesn't multiply nested output (#1285) [Dylan Thacker-Smith]
+* Fix duplication of text in raw tags (#1304) [Peter Zhu]
+* Fix strict parsing of find variable with a name expression (#1317) [Dylan Thacker-Smith]
+* Use monotonic time to measure durations in Liquid::Profiler (#1362) [Dylan Thacker-Smith]
+
+### Breaking Changes
+* Require Ruby >= 2.5 (#1131, #1310) [Mike Angell, Dylan Thacker-Smith]
+* Remove support for taint checking (#1268) [Dylan Thacker-Smith]
+* Split Strainer class into StrainerFactory and StrainerTemplate (#1208) [Thierry Joyal]
+* Remove handling of a nil context in the Strainer class (#1218) [Thierry Joyal]
+* Handle `BlockBody#blank?` at parse time (#1287) [Dylan Thacker-Smith]
+* Pass the tag markup and tokenizer to `Document#unknown_tag` (#1290) [Dylan Thacker-Smith]
+* And several internal changes
+
+### Performance Improvements
+* Reduce allocations (#1073, #1091, #1115, #1099, #1117, #1141, #1322, #1341) [Richard Monette, Florian Weingarten, Ashwin Maroli]
+* Improve resources limits performance (#1093, #1323) [Florian Weingarten, Dylan Thacker-Smith]
+
 ## 4.0.3 / 2019-03-12
 
 ### Fixed
@@ -274,7 +317,7 @@ Yanked from rubygems, as it contained too many changes that broke compatibility.
 * Fixed bad error reporting when a filter called a method which doesn't exist. Liquid told you that it couldn't find the filter which was obviously misleading [Tobias Luetke]
 * Removed count helper from standard lib. use size [Tobias Luetke]
 * Fixed bug with string filter parameters failing to tolerate commas in strings. [Paul Hammond]
-* Improved filter parameters. Filter parameters are now context sensitive; Types are resolved according to the rules of the context. Multiple parameters are now separated by the Liquid::ARGUMENT_SEPARATOR: , by default [Paul Hammond]
+* Improved filter parameters. Filter parameters are now context sensitive; Types are resolved according to the rules of the context. Multiple parameters are now separated by the Liquid::ArgumentSeparator: , by default [Paul Hammond]
     {{ 'Typo' | link_to: 'http://typo.leetsoft.com', 'Typo - a modern weblog engine' }}
 * Added Liquid::Drop. A base class which you can use for exporting proxy objects to liquid which can acquire more data when used in liquid. [Tobias Luetke]
 

README.md

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

Rakefile

@@ -2,16 +2,22 @@
 
 require 'rake'
 require 'rake/testtask'
-$LOAD_PATH.unshift(File.expand_path('lib', __dir__))
-require 'liquid/version'
+$LOAD_PATH.unshift(File.expand_path("../lib", __FILE__))
+require "liquid/version"
 
-task(default: %i[test rubocop])
+task(default: [:test, :rubocop])
 
 desc('run test suite with default parser')
 Rake::TestTask.new(:base_test) do |t|
-  t.libs << '.' << 'lib' << 'test'
+  t.libs << 'lib' << 'test'
   t.test_files = FileList['test/{integration,unit}/**/*_test.rb']
-  t.verbose = false
+  t.verbose    = false
+end
+
+Rake::TestTask.new(:integration_test) do |t|
+  t.libs << 'lib' << 'test'
+  t.test_files = FileList['test/integration/**/*_test.rb']
+  t.verbose    = false
 end
 
 desc('run test suite with warn error mode')
@@ -37,22 +43,21 @@ task :test do
   Rake::Task['base_test'].invoke
 
   if RUBY_ENGINE == 'ruby' || RUBY_ENGINE == 'truffleruby'
-
     ENV['LIQUID_C'] = '1'
 
     ENV['LIQUID_PARSER_MODE'] = 'lax'
-    Rake::Task['base_test'].reenable
-    Rake::Task['base_test'].invoke
+    Rake::Task['integration_test'].reenable
+    Rake::Task['integration_test'].invoke
 
     ENV['LIQUID_PARSER_MODE'] = 'strict'
-    Rake::Task['base_test'].reenable
-    Rake::Task['base_test'].invoke
+    Rake::Task['integration_test'].reenable
+    Rake::Task['integration_test'].invoke
   end
 end
 
 task(gem: :build)
 task :build do
-  system 'gem build liquid.gemspec'
+  system "gem build liquid.gemspec"
 end
 
 task install: :build do
@@ -61,45 +66,45 @@ end
 
 task release: :build do
   system "git tag -a v#{Liquid::VERSION} -m 'Tagging #{Liquid::VERSION}'"
-  system 'git push --tags'
+  system "git push --tags"
   system "gem push liquid-#{Liquid::VERSION}.gem"
   system "rm liquid-#{Liquid::VERSION}.gem"
 end
 
 namespace :benchmark do
-  desc 'Run the liquid benchmark with lax parsing'
+  desc "Run the liquid benchmark with lax parsing"
   task :run do
-    ruby './performance/benchmark.rb lax'
+    ruby "./performance/benchmark.rb lax"
   end
 
-  desc 'Run the liquid benchmark with strict parsing'
+  desc "Run the liquid benchmark with strict parsing"
   task :strict do
-    ruby './performance/benchmark.rb strict'
+    ruby "./performance/benchmark.rb strict"
   end
 end
 
 namespace :profile do
-  desc 'Run the liquid profile/performance coverage'
+  desc "Run the liquid profile/performance coverage"
   task :run do
-    ruby './performance/profile.rb'
+    ruby "./performance/profile.rb"
   end
 
-  desc 'Run the liquid profile/performance coverage with strict parsing'
+  desc "Run the liquid profile/performance coverage with strict parsing"
   task :strict do
-    ruby './performance/profile.rb strict'
+    ruby "./performance/profile.rb strict"
   end
 end
 
 namespace :memory_profile do
-  desc 'Run memory profiler'
+  desc "Run memory profiler"
   task :run do
-    ruby './performance/memory_profile.rb'
+    ruby "./performance/memory_profile.rb"
   end
 end
 
-desc('Run example')
+desc("Run example")
 task :example do
-  ruby '-w -d -Ilib example/server/server.rb'
+  ruby "-w -d -Ilib example/server/server.rb"
 end
 
 task :console do

example/server/example_servlet.rb

@@ -2,7 +2,7 @@
 
 module ProductsFilter
   def price(integer)
-    format('$%.2d USD', integer / 100.0)
+    format("$%.2d USD", integer / 100.0)
   end
 
   def prettyprint(text)
@@ -30,17 +30,17 @@ class Servlet < LiquidServlet
   private
 
   def products_list
-    [{ 'name' => 'Arbor Draft', 'price' => 39_900, 'description' => 'the *arbor draft* is a excellent product' },
-     { 'name' => 'Arbor Element', 'price' => 40_000, 'description' => 'the *arbor element* rocks for freestyling' },
-     { 'name' => 'Arbor Diamond', 'price' => 59_900, 'description' => 'the *arbor diamond* is a made up product because im obsessed with arbor and have no creativity' }]
+    [{ 'name' => 'Arbor Draft', 'price' => 39900, 'description' => 'the *arbor draft* is a excellent product' },
+     { 'name' => 'Arbor Element', 'price' => 40000, 'description' => 'the *arbor element* rocks for freestyling' },
+     { 'name' => 'Arbor Diamond', 'price' => 59900, 'description' => 'the *arbor diamond* is a made up product because im obsessed with arbor and have no creativity' }]
   end
 
   def more_products_list
-    [{ 'name' => 'Arbor Catalyst', 'price' => 39_900, 'description' => 'the *arbor catalyst* is an advanced drop-through for freestyle and flatground performance and versatility' },
-     { 'name' => 'Arbor Fish', 'price' => 40_000, 'description' => 'the *arbor fish* is a compact pin that features an extended wheelbase and time-honored teardrop shape' }]
+    [{ 'name' => 'Arbor Catalyst', 'price' => 39900, 'description' => 'the *arbor catalyst* is an advanced drop-through for freestyle and flatground performance and versatility' },
+     { 'name' => 'Arbor Fish', 'price' => 40000, 'description' => 'the *arbor fish* is a compact pin that features an extended wheelbase and time-honored teardrop shape' }]
   end
 
   def description
-    'List of Products ~ This is a list of products with price and description.'
+    "List of Products ~ This is a list of products with price and description."
   end
 end

example/server/liquid_servlet.rb

@@ -1,30 +1,27 @@
 # frozen_string_literal: true
 
 class LiquidServlet < WEBrick::HTTPServlet::AbstractServlet
-  def get(req, res)
+  def do_GET(req, res)
     handle(:get, req, res)
   end
 
-  def post(req, res)
+  def do_POST(req, res)
     handle(:post, req, res)
   end
 
-  alias_method :do_GET, :get
-  alias_method :do_POST, :post
-
   private
 
   def handle(_type, req, res)
-    @request = req
+    @request  = req
     @response = res
 
     @request.path_info =~ /(\w+)\z/
-    @action = Regexp.last_match(1) || 'index'
+    @action  = Regexp.last_match(1) || 'index'
     @assigns = send(@action) if respond_to?(@action)
 
-    @response['Content-Type'] = 'text/html'
+    @response['Content-Type'] = "text/html"
     @response.status = 200
-    @response.body = Liquid::Template.parse(read_template).render(@assigns, filters: [ProductsFilter])
+    @response.body   = Liquid::Template.parse(read_template).render(@assigns, filters: [ProductsFilter])
   end
 
   def read_template(filename = @action)

example/server/server.rb

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

lib/liquid.rb

@@ -22,31 +22,33 @@
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 module Liquid
-  FILTER_SEPARATOR = /\|/.freeze
-  ARGUMENT_SEPARATOR = ','
-  FILTER_ARGUMENT_SEPARATOR = ':'
-  VARIABLE_ATTRIBUTE_SEPARATOR = '.'
-  WHITESPACE_CONTROL = '-'
-  TAG_START = /\{\%/.freeze
-  TAG_END = /\%\}/.freeze
-  VARIABLE_SIGNATURE = /\(?[\w\-\.\[\]]\)?/.freeze
-  VARIABLE_SEGMENT = /[\w\-]/.freeze
-  VARIABLE_START = /\{\{/.freeze
-  VARIABLE_END = /\}\}/.freeze
-  VARIABLE_INCOMPLETE_END = /\}\}?/.freeze
-  QUOTED_STRING = /"[^"]*"|'[^']*'/.freeze
-  QUOTED_FRAGMENT = /#{QUOTED_STRING}|(?:[^\s,\|'"]|#{QUOTED_STRING})+/o.freeze
-  TAG_ATTRIBUTES = /(\w+)\s*\:\s*(#{QUOTED_FRAGMENT})/o.freeze
-  ANY_STARTING_TAG = /#{TAG_START}|#{VARIABLE_START}/o.freeze
-  PARTIAL_TEMPLATE_PARSER = /#{TAG_START}.*?#{TAG_END}|#{VARIABLE_START}.*?#{VARIABLE_INCOMPLETE_END}/om.freeze
-  TEMPLATE_PARSER = /(#{PARTIAL_TEMPLATE_PARSER}|#{ANY_STARTING_TAG})/om.freeze
-  VARIABLE_PARSER = /\[[^\]]+\]|#{VARIABLE_SEGMENT}+\??/o.freeze
+  FilterSeparator             = /\|/
+  ArgumentSeparator           = ','
+  FilterArgumentSeparator     = ':'
+  VariableAttributeSeparator  = '.'
+  WhitespaceControl           = '-'
+  TagStart                    = /\{\%/
+  TagEnd                      = /\%\}/
+  VariableSignature           = /\(?[\w\-\.\[\]]\)?/
+  VariableSegment             = /[\w\-]/
+  VariableStart               = /\{\{/
+  VariableEnd                 = /\}\}/
+  VariableIncompleteEnd       = /\}\}?/
+  QuotedString                = /"[^"]*"|'[^']*'/
+  QuotedFragment              = /#{QuotedString}|(?:[^\s,\|'"]|#{QuotedString})+/o
+  TagAttributes               = /(\w+)\s*\:\s*(#{QuotedFragment})/o
+  AnyStartingTag              = /#{TagStart}|#{VariableStart}/o
+  PartialTemplateParser       = /#{TagStart}.*?#{TagEnd}|#{VariableStart}.*?#{VariableIncompleteEnd}/om
+  TemplateParser              = /(#{PartialTemplateParser}|#{AnyStartingTag})/om
+  VariableParser              = /\[[^\]]+\]|#{VariableSegment}+\??/o
+
+  RAISE_EXCEPTION_LAMBDA = ->(_e) { raise }
 
   singleton_class.send(:attr_accessor, :cache_classes)
   self.cache_classes = true
 end
 
-require 'liquid/version'
+require "liquid/version"
 require 'liquid/parse_tree_visitor'
 require 'liquid/lexer'
 require 'liquid/parser'
@@ -57,11 +59,14 @@ require 'liquid/forloop_drop'
 require 'liquid/extensions'
 require 'liquid/errors'
 require 'liquid/interrupts'
-require 'liquid/strainer'
+require 'liquid/strainer_factory'
+require 'liquid/strainer_template'
 require 'liquid/expression'
 require 'liquid/context'
 require 'liquid/parser_switching'
 require 'liquid/tag'
+require 'liquid/tag/disabler'
+require 'liquid/tag/disableable'
 require 'liquid/block'
 require 'liquid/block_body'
 require 'liquid/document'
@@ -76,6 +81,11 @@ require 'liquid/condition'
 require 'liquid/utils'
 require 'liquid/tokenizer'
 require 'liquid/parse_context'
+require 'liquid/partial_cache'
+require 'liquid/usage'
+require 'liquid/register'
+require 'liquid/static_registers'
+require 'liquid/template_factory'
 
 # Load all the tags of the standard library
 #

lib/liquid/block.rb

@@ -10,9 +10,10 @@ module Liquid
     end
 
     def parse(tokens)
-      @body = BlockBody.new
+      @body = new_body
       while parse_body(@body, tokens)
       end
+      @body.freeze
     end
 
     # For backwards compatibility
@@ -28,20 +29,29 @@ module Liquid
       @body.nodelist
     end
 
-    def unknown_tag(tag, _params, _tokens)
+    def unknown_tag(tag_name, _markup, _tokenizer)
+      Block.raise_unknown_tag(tag_name, block_name, block_delimiter, parse_context)
+    end
+
+    # @api private
+    def self.raise_unknown_tag(tag, block_name, block_delimiter, parse_context)
       if tag == 'else'
-        raise SyntaxError, parse_context.locale.t('errors.syntax.unexpected_else',
-                                                  block_name: block_name)
+        raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_else",
+          block_name: block_name)
       elsif tag.start_with?('end')
-        raise SyntaxError, parse_context.locale.t('errors.syntax.invalid_delimiter',
-                                                  tag: tag,
-                                                  block_name: block_name,
-                                                  block_delimiter: block_delimiter)
+        raise SyntaxError, parse_context.locale.t("errors.syntax.invalid_delimiter",
+          tag: tag,
+          block_name: block_name,
+          block_delimiter: block_delimiter)
       else
-        raise SyntaxError, parse_context.locale.t('errors.syntax.unknown_tag', tag: tag)
+        raise SyntaxError, parse_context.locale.t("errors.syntax.unknown_tag", tag: tag)
       end
     end
 
+    def raise_tag_never_closed(block_name)
+      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed", block_name: block_name)
+    end
+
     def block_name
       @tag_name
     end
@@ -50,18 +60,25 @@ module Liquid
       @block_delimiter ||= "end#{block_name}"
     end
 
-    protected
+    private
 
+    # @api public
+    def new_body
+      parse_context.new_block_body
+    end
+
+    # @api public
     def parse_body(body, tokens)
-      raise StackLevelError, 'Nesting too deep' if parse_context.depth >= MAX_DEPTH
-
+      if parse_context.depth >= MAX_DEPTH
+        raise StackLevelError, "Nesting too deep"
+      end
       parse_context.depth += 1
       begin
         body.parse(tokens, parse_context) do |end_tag_name, end_tag_params|
           @blank &&= body.blank?
 
           return false if end_tag_name == block_delimiter
-          raise SyntaxError, parse_context.locale.t('errors.syntax.tag_never_closed', block_name: block_name) unless end_tag_name
+          raise_tag_never_closed(block_name) unless end_tag_name
 
           # this tag is not registered with the system
           # pass it to the current block for special handling or error reporting

lib/liquid/block_body.rb

@@ -1,50 +1,156 @@
 # frozen_string_literal: true
 
+require 'English'
+
 module Liquid
   class BlockBody
-    FULL_TOKEN = /\A#{TAG_START}#{WHITESPACE_CONTROL}?\s*(\w+)\s*(.*?)#{WHITESPACE_CONTROL}?#{TAG_END}\z/om.freeze
-    CONTENT_OF_VARIABLE = /\A#{VARIABLE_START}#{WHITESPACE_CONTROL}?(.*?)#{WHITESPACE_CONTROL}?#{VARIABLE_END}\z/om.freeze
-    WHITESPACE_OR_NOTHING = /\A\s*\z/.freeze
-    TAG_START = '{%'
-    VAR_START = '{{'
+    LiquidTagToken      = /\A\s*(\w+)\s*(.*?)\z/o
+    FullToken           = /\A#{TagStart}#{WhitespaceControl}?(\s*)(\w+)(\s*)(.*?)#{WhitespaceControl}?#{TagEnd}\z/om
+    ContentOfVariable   = /\A#{VariableStart}#{WhitespaceControl}?(.*?)#{WhitespaceControl}?#{VariableEnd}\z/om
+    WhitespaceOrNothing = /\A\s*\z/
+    TAGSTART            = "{%"
+    VARSTART            = "{{"
 
     attr_reader :nodelist
 
     def initialize
       @nodelist = []
-      @blank = true
+      @blank    = true
     end
 
-    def parse(tokenizer, parse_context)
-      parse_context.line_number = tokenizer.line_number
-      while (token = tokenizer.shift)
-        next if token.empty?
+    def parse(tokenizer, parse_context, &block)
+      raise FrozenError, "can't modify frozen Liquid::BlockBody" if frozen?
 
-        case
-        when token.start_with?(TAG_START)
-          whitespace_handler(token, parse_context)
-          raise_missing_tag_terminator(token, parse_context) unless token =~ FULL_TOKEN
+      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
+
+    def freeze
+      @nodelist.freeze
+      super
+    end
+
+    private def parse_for_liquid_tag(tokenizer, parse_context)
+      while (token = tokenizer.shift)
+        unless token.empty? || token =~ WhitespaceOrNothing
+          unless token =~ LiquidTagToken
+            # line isn't empty but didn't match tag syntax, yield and let the
+            # caller raise a syntax error
+            return yield token, token
+          end
           tag_name = Regexp.last_match(1)
-          markup = Regexp.last_match(2)
-          # fetch the tag from registered blocks
+          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
-        when token.start_with?(VAR_START)
+        end
+        parse_context.line_number = tokenizer.line_number
+      end
+
+      yield nil, nil
+    end
+
+    # @api private
+    def self.unknown_tag_in_liquid_tag(tag, parse_context)
+      Block.raise_unknown_tag(tag, 'liquid', '%}', parse_context)
+    end
+
+    # @api private
+    def self.raise_missing_tag_terminator(token, parse_context)
+      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_termination", token: token, tag_end: TagEnd.inspect)
+    end
+
+    # @api private
+    def self.raise_missing_variable_terminator(token, parse_context)
+      raise SyntaxError, parse_context.locale.t("errors.syntax.variable_termination", token: token, tag_end: VariableEnd.inspect)
+    end
+
+    # @api private
+    def self.render_node(context, output, node)
+      node.render_to_output_buffer(context, output)
+    rescue => exc
+      blank_tag = !node.instance_of?(Variable) && node.blank?
+      rescue_render_node(context, output, node.line_number, exc, blank_tag)
+    end
+
+    # @api private
+    def self.rescue_render_node(context, output, line_number, exc, blank_tag)
+      case exc
+      when MemoryError
+        raise
+      when UndefinedVariable, UndefinedDropMethod, UndefinedFilter
+        context.handle_error(exc, line_number)
+      else
+        error_message = context.handle_error(exc, line_number)
+        unless blank_tag # conditional for backwards compatibility
+          output << error_message
+        end
+      end
+    end
+
+    private def parse_liquid_tag(markup, parse_context)
+      liquid_tag_tokenizer = parse_context.new_tokenizer(
+        markup, start_line_number: parse_context.line_number, for_liquid_tag: true
+      )
+      parse_for_liquid_tag(liquid_tag_tokenizer, parse_context) do |end_tag_name, _end_tag_markup|
+        if end_tag_name
+          BlockBody.unknown_tag_in_liquid_tag(end_tag_name, parse_context)
+        end
+      end
+    end
+
+    private def parse_for_document(tokenizer, parse_context)
+      while (token = tokenizer.shift)
+        next if token.empty?
+        case
+        when token.start_with?(TAGSTART)
+          whitespace_handler(token, parse_context)
+          unless token =~ FullToken
+            BlockBody.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'
+            parse_liquid_tag(markup, parse_context)
+            next
+          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
-          token.lstrip! if parse_context.trim_whitespace
+          if parse_context.trim_whitespace
+            token.lstrip!
+          end
           parse_context.trim_whitespace = false
           @nodelist << token
-          @blank &&= token.match?(WHITESPACE_OR_NOTHING)
+          @blank &&= !!(token =~ WhitespaceOrNothing)
         end
         parse_context.line_number = tokenizer.line_number
       end
@@ -53,49 +159,66 @@ module Liquid
     end
 
     def whitespace_handler(token, parse_context)
-      if token[2] == WHITESPACE_CONTROL
+      if token[2] == WhitespaceControl
         previous_token = @nodelist.last
-        previous_token.rstrip! if previous_token.is_a?(String)
+        if previous_token.is_a?(String)
+          first_byte = previous_token.getbyte(0)
+          previous_token.rstrip!
+          if previous_token.empty? && parse_context[:bug_compatible_whitespace_trimming] && first_byte
+            previous_token << first_byte
+          end
+        end
       end
-      parse_context.trim_whitespace = (token[-3] == WHITESPACE_CONTROL)
+      parse_context.trim_whitespace = (token[-3] == WhitespaceControl)
     end
 
     def blank?
       @blank
     end
 
+    # Remove blank strings in the block body for a control flow tag (e.g. `if`, `for`, `case`, `unless`)
+    # with a blank body.
+    #
+    # For example, in a conditional assignment like the following
+    #
+    # ```
+    # {% if size > max_size %}
+    #   {% assign size = max_size %}
+    # {% endif %}
+    # ```
+    #
+    # we assume the intention wasn't to output the blank spaces in the `if` tag's block body, so this method
+    # will remove them to reduce the render output size.
+    #
+    # Note that it is now preferred to use the `liquid` tag for this use case.
+    def remove_blank_strings
+      raise "remove_blank_strings only support being called on a blank block body" unless @blank
+      @nodelist.reject! { |node| node.instance_of?(String) }
+    end
+
     def render(context)
       render_to_output_buffer(context, +'')
     end
 
     def render_to_output_buffer(context, output)
-      context.resource_limits.render_score += @nodelist.length
+      freeze unless frozen?
+
+      context.resource_limits.increment_render_score(@nodelist.length)
 
       idx = 0
       while (node = @nodelist[idx])
-        previous_output_size = output.bytesize
-
-        case node
-        when String
+        if node.instance_of?(String)
           output << node
-        when Variable
+        else
           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
           # 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
+          # or {% continue %}. These tags may also occur through Block or Include tags.
+          break if context.interrupt? # might have happened in a for-block
         end
         idx += 1
 
-        raise_if_resource_limits_reached(context, output.bytesize - previous_output_size)
+        context.resource_limits.increment_write_score(output)
       end
 
       output
@@ -104,35 +227,25 @@ module Liquid
     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 raise_if_resource_limits_reached(context, length)
-      context.resource_limits.render_length += length
-      return unless context.resource_limits.reached?
-
-      raise MemoryError, 'Memory limits exceeded'
+      BlockBody.render_node(context, output, node)
     end
 
     def create_variable(token, parse_context)
-      token.scan(CONTENT_OF_VARIABLE) do |content|
+      token.scan(ContentOfVariable) do |content|
         markup = content.first
         return Variable.new(markup, parse_context)
       end
-      raise_missing_variable_terminator(token, parse_context)
+      BlockBody.raise_missing_variable_terminator(token, parse_context)
     end
 
+    # @deprecated Use {.raise_missing_tag_terminator} instead
     def raise_missing_tag_terminator(token, parse_context)
-      raise SyntaxError, parse_context.locale.t('errors.syntax.tag_termination', token: token, tag_end: TAG_END.inspect)
+      BlockBody.raise_missing_tag_terminator(token, parse_context)
     end
 
+    # @deprecated Use {.raise_missing_variable_terminator} instead
     def raise_missing_variable_terminator(token, parse_context)
-      raise SyntaxError, parse_context.locale.t('errors.syntax.variable_termination', token: token, tag_end: VARIABLE_END.inspect)
+      BlockBody.raise_missing_variable_terminator(token, parse_context)
     end
 
     def registered_tags

lib/liquid/condition.rb

@@ -9,7 +9,7 @@ module Liquid
   #   c.evaluate #=> true
   #
   class Condition #:nodoc:
-    @operators = {
+    @@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) },
@@ -27,18 +27,37 @@ module Liquid
       end,
     }
 
-    class << self
-      attr_accessor :operators
+    class MethodLiteral
+      attr_reader :method_name, :to_s
+
+      def initialize(method_name, to_s)
+        @method_name = method_name
+        @to_s = to_s
+      end
+    end
+
+    @@method_literals = {
+      'blank' => MethodLiteral.new(:blank?, '').freeze,
+      'empty' => MethodLiteral.new(:empty?, '').freeze,
+    }
+
+    def self.operators
+      @@operators
+    end
+
+    def self.parse_expression(parse_context, markup)
+      @@method_literals[markup] || parse_context.parse_expression(markup)
     end
 
     attr_reader :attachment, :child_condition
     attr_accessor :left, :operator, :right
 
     def initialize(left = nil, operator = nil, right = nil)
-      @left = left
+      @left     = left
       @operator = operator
-      @right = right
-      @child_relation = nil
+      @right    = right
+
+      @child_relation  = nil
       @child_condition = nil
     end
 
@@ -62,12 +81,12 @@ module Liquid
     end
 
     def or(condition)
-      @child_relation = :or
+      @child_relation  = :or
       @child_condition = condition
     end
 
     def and(condition)
-      @child_relation = :and
+      @child_relation  = :and
       @child_condition = condition
     end
 
@@ -90,7 +109,7 @@ module Liquid
     private
 
     def equal_variables(left, right)
-      if left.is_a?(Liquid::Expression::MethodLiteral)
+      if left.is_a?(MethodLiteral)
         if right.respond_to?(left.method_name)
           return right.send(left.method_name)
         else
@@ -98,7 +117,7 @@ module Liquid
         end
       end
 
-      if right.is_a?(Liquid::Expression::MethodLiteral)
+      if right.is_a?(MethodLiteral)
         if left.respond_to?(right.method_name)
           return left.send(right.method_name)
         else
@@ -115,7 +134,7 @@ module Liquid
       # return this as the result.
       return context.evaluate(left) if op.nil?
 
-      left = context.evaluate(left)
+      left  = context.evaluate(left)
       right = context.evaluate(right)
 
       operation = self.class.operators[op] || raise(Liquid::ArgumentError, "Unknown operator #{op}")

lib/liquid/context.rb

@@ -14,35 +14,49 @@ module Liquid
   #
   #   context['bob']  #=> nil  class Context
   class Context
-    attr_reader :scopes, :errors, :registers, :environments, :resource_limits
+    attr_reader :scopes, :errors, :registers, :environments, :resource_limits, :static_registers, :static_environments
     attr_accessor :exception_renderer, :template_name, :partial, :global_filter, :strict_variables, :strict_filters
 
-    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
+    # rubocop:disable Metrics/ParameterLists
+    def self.build(environments: {}, outer_scope: {}, registers: {}, rethrow_errors: false, resource_limits: nil, static_environments: {}, &block)
+      new(environments, outer_scope, registers, rethrow_errors, resource_limits, static_environments, &block)
+    end
 
-      @this_stack_used = false
+    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
+      @interrupts          = []
+      @filters             = []
+      @global_filter       = nil
+      @disabled_tags       = {}
 
       self.exception_renderer = Template.default_exception_renderer
-      self.exception_renderer = ->(_e) { raise } if rethrow_errors
+      if rethrow_errors
+        self.exception_renderer = Liquid::RAISE_EXCEPTION_LAMBDA
+      end
 
-      @interrupts = []
-      @filters = []
-      @global_filter = nil
+      yield self if block_given?
+
+      # Do this last, since it could result in this object being passed to a Proc in the environment
+      squash_instance_assigns_with_environments
     end
+    # rubocop:enable Metrics/ParameterLists
 
     def warnings
       @warnings ||= []
     end
 
     def strainer
-      @strainer ||= Strainer.create(self, @filters)
+      @strainer ||= StrainerFactory.create(self, @filters)
     end
 
     # Adds filters to this context.
@@ -77,7 +91,7 @@ module Liquid
     def handle_error(e, line_number = nil)
       e = internal_error unless e.is_a?(Liquid::Error)
       e.template_name ||= template_name
-      e.line_number ||= line_number
+      e.line_number   ||= line_number
       errors.push(e)
       exception_renderer.call(e).to_s
     end
@@ -89,7 +103,7 @@ module Liquid
     # Push new local scope on the stack. use <tt>Context#stack</tt> instead
     def push(new_scope = {})
       @scopes.unshift(new_scope)
-      raise StackLevelError, 'Nesting too deep' if @scopes.length > Block::MAX_DEPTH
+      check_overflow
     end
 
     # Merge a hash of variables in the current local scope
@@ -100,7 +114,6 @@ module Liquid
     # Pop from the stack. use <tt>Context#stack</tt> instead
     def pop
       raise ContextError if @scopes.size == 1
-
       @scopes.shift
     end
 
@@ -112,19 +125,31 @@ module Liquid
     #   end
     #
     #   context['var]  #=> nil
-    def stack(new_scope = nil)
-      old_stack_used = @this_stack_used
-      if new_scope
-        push(new_scope)
-        @this_stack_used = true
-      else
-        @this_stack_used = false
-      end
-
+    def stack(new_scope = {})
+      push(new_scope)
       yield
     ensure
-      pop if @this_stack_used
-      @this_stack_used = old_stack_used
+      pop
+    end
+
+    # Creates a new context inheriting resource limits, filters, environment etc.,
+    # but with an isolated scope.
+    def new_isolated_subcontext
+      check_overflow
+
+      self.class.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
+        subcontext.disabled_tags = @disabled_tags
+      end
     end
 
     def clear_instance_assigns
@@ -133,10 +158,6 @@ module Liquid
 
     # Only allow String, Numeric, Hash, Array, Proc, Boolean or <tt>Liquid::Drop</tt>
     def []=(key, value)
-      unless @this_stack_used
-        @this_stack_used = true
-        push({})
-      end
       @scopes[0][key] = value
     end
 
@@ -165,33 +186,23 @@ 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 = nil
-
-      if scope.nil?
-        @environments.each do |e|
-          variable = lookup_and_evaluate(e, key, raise_on_not_found: raise_on_not_found)
-          # When lookup returned a value OR there is no value but the lookup also did not raise
-          # then it is the value we are looking for.
-          if !variable.nil? || @strict_variables && raise_on_not_found
-            scope = e
-            break
-          end
-        end
+      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)
       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         = variable.to_liquid
       variable.context = self if variable.respond_to?(:context=)
 
       variable
     end
 
     def lookup_and_evaluate(obj, key, raise_on_not_found: true)
-      raise Liquid::UndefinedVariable, "undefined variable #{key}" if @strict_variables && raise_on_not_found && obj.respond_to?(:key?) && !obj.key?(key)
+      if @strict_variables && raise_on_not_found && obj.respond_to?(:key?) && !obj.key?(key)
+        raise Liquid::UndefinedVariable, "undefined variable #{key}"
+      end
 
       value = obj[key]
 
@@ -202,13 +213,58 @@ module Liquid
       end
     end
 
+    def with_disabled_tags(tag_names)
+      tag_names.each do |name|
+        @disabled_tags[name] = @disabled_tags.fetch(name, 0) + 1
+      end
+      yield
+    ensure
+      tag_names.each do |name|
+        @disabled_tags[name] -= 1
+      end
+    end
+
+    def tag_disabled?(tag_name)
+      @disabled_tags.fetch(tag_name, 0) > 0
+    end
+
+    protected
+
+    attr_writer :base_scope_depth, :warnings, :errors, :strainer, :filters, :disabled_tags
+
     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)
+        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)
+        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'
-    rescue Liquid::InternalError => e
-      e
+    rescue Liquid::InternalError => exc
+      exc
     end
 
     def squash_instance_assigns_with_environments

lib/liquid/document.rb

@@ -1,28 +1,64 @@
 # frozen_string_literal: true
 
 module Liquid
-  class Document < BlockBody
+  class Document
     def self.parse(tokens, parse_context)
-      doc = new
+      doc = new(parse_context)
       doc.parse(tokens, parse_context)
       doc
     end
 
-    def parse(tokens, parse_context)
-      super do |end_tag_name, _end_tag_params|
-        unknown_tag(end_tag_name, parse_context) if end_tag_name
+    attr_reader :parse_context, :body
+
+    def initialize(parse_context)
+      @parse_context = parse_context
+      @body = new_body
+    end
+
+    def nodelist
+      @body.nodelist
+    end
+
+    def parse(tokenizer, parse_context)
+      while parse_body(tokenizer)
       end
+      @body.freeze
     rescue SyntaxError => e
       e.line_number ||= parse_context.line_number
       raise
     end
 
-    def unknown_tag(tag, parse_context)
+    def unknown_tag(tag, _markup, _tokenizer)
       case tag
       when 'else', 'end'
-        raise SyntaxError, parse_context.locale.t('errors.syntax.unexpected_outer_tag', tag: tag)
+        raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_outer_tag", tag: tag)
       else
-        raise SyntaxError, parse_context.locale.t('errors.syntax.unknown_tag', tag: tag)
+        raise SyntaxError, parse_context.locale.t("errors.syntax.unknown_tag", tag: tag)
+      end
+    end
+
+    def render_to_output_buffer(context, output)
+      @body.render_to_output_buffer(context, output)
+    end
+
+    def render(context)
+      render_to_output_buffer(context, +'')
+    end
+
+    private
+
+    def new_body
+      parse_context.new_block_body
+    end
+
+    def parse_body(tokenizer)
+      @body.parse(tokenizer, parse_context) do |unknown_tag_name, unknown_tag_markup|
+        if unknown_tag_name
+          unknown_tag(unknown_tag_name, unknown_tag_markup, tokenizer)
+          true
+        else
+          false
+        end
       end
     end
   end

lib/liquid/drop.rb

@@ -28,7 +28,6 @@ module Liquid
     # Catch all for the method
     def liquid_method_missing(method)
       return nil unless @context&.strict_variables
-
       raise Liquid::UndefinedDropMethod, "undefined method #{method}"
     end
 
@@ -70,7 +69,7 @@ module Liquid
 
         if include?(Enumerable)
           blacklist += Enumerable.public_instance_methods
-          blacklist -= %i[sort count first min max include?]
+          blacklist -= [:sort, :count, :first, :min, :max]
         end
 
         whitelist = [:to_liquid] + (public_instance_methods - blacklist)

lib/liquid/errors.rb

@@ -7,12 +7,12 @@ module Liquid
     attr_accessor :markup_context
 
     def to_s(with_prefix = true)
-      str = +''
+      str = +""
       str << message_prefix if with_prefix
       str << super()
 
       if markup_context
-        str << ' '
+        str << " "
         str << markup_context
       end
 
@@ -22,37 +22,37 @@ module Liquid
     private
 
     def message_prefix
-      str = +''
+      str = +""
       str << if is_a?(SyntaxError)
-        'Liquid syntax error'
+        "Liquid syntax error"
       else
-        'Liquid error'
+        "Liquid error"
       end
 
       if line_number
-        str << ' ('
-        str << template_name << ' ' if template_name
-        str << 'line ' << line_number.to_s << ')'
+        str << " ("
+        str << template_name << " " if template_name
+        str << "line " << line_number.to_s << ")"
       end
 
-      str << ': '
+      str << ": "
       str
     end
   end
 
-  ArgumentError = Class.new(Error)
-  ContextError = Class.new(Error)
-  FileSystemError = Class.new(Error)
-  StandardError = Class.new(Error)
-  SyntaxError = Class.new(Error)
-  StackLevelError = Class.new(Error)
-  TaintedError = Class.new(Error)
-  MemoryError = Class.new(Error)
-  ZeroDivisionError = Class.new(Error)
-  FloatDomainError = Class.new(Error)
-  UndefinedVariable = Class.new(Error)
+  ArgumentError       = Class.new(Error)
+  ContextError        = Class.new(Error)
+  FileSystemError     = Class.new(Error)
+  StandardError       = Class.new(Error)
+  SyntaxError         = Class.new(Error)
+  StackLevelError     = Class.new(Error)
+  MemoryError         = Class.new(Error)
+  ZeroDivisionError   = Class.new(Error)
+  FloatDomainError    = Class.new(Error)
+  UndefinedVariable   = Class.new(Error)
   UndefinedDropMethod = Class.new(Error)
-  UndefinedFilter = Class.new(Error)
+  UndefinedFilter     = Class.new(Error)
   MethodOverrideError = Class.new(Error)
-  InternalError = Class.new(Error)
+  DisabledError       = Class.new(Error)
+  InternalError       = Class.new(Error)
 end

lib/liquid/expression.rb

@@ -2,46 +2,39 @@
 
 module Liquid
   class Expression
-    class MethodLiteral
-      attr_reader :method_name, :to_s
-
-      def initialize(method_name, to_s)
-        @method_name = method_name
-        @to_s = to_s
-      end
-
-      def to_liquid
-        to_s
-      end
-    end
-
     LITERALS = {
       nil => nil, 'nil' => nil, 'null' => nil, '' => nil,
       'true' => true,
       'false' => false,
-      'blank' => MethodLiteral.new(:blank?, '').freeze,
-      'empty' => MethodLiteral.new(:empty?, '').freeze
+      'blank' => '',
+      'empty' => ''
     }.freeze
 
-    SINGLE_QUOTED_STRING = /\A'(.*)'\z/m.freeze
-    DOUBLE_QUOTED_STRING = /\A"(.*)"\z/m.freeze
-    INTEGERS_REGEX       = /\A(-?\d+)\z/.freeze
-    FLOATS_REGEX         = /\A(-?\d[\d\.]+)\z/.freeze
-    RANGES_REGEX         = /\A\((\S+)\.\.(\S+)\)\z/.freeze
+    SINGLE_QUOTED_STRING = /\A\s*'(.*)'\s*\z/m
+    DOUBLE_QUOTED_STRING = /\A\s*"(.*)"\s*\z/m
+    INTEGERS_REGEX       = /\A\s*(-?\d+)\s*\z/
+    FLOATS_REGEX         = /\A\s*(-?\d[\d\.]+)\s*\z/
+
+    # Use an atomic group (?>...) to avoid pathological backtracing from
+    # malicious input as described in https://github.com/Shopify/liquid/issues/1357
+    RANGES_REGEX         = /\A\s*\(\s*(?>(\S+)\s*\.\.)\s*(\S+)\s*\)\s*\z/
 
     def self.parse(markup)
-      if LITERALS.key?(markup)
-        LITERALS[markup]
+      case markup
+      when nil
+        nil
+      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
       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
+        markup = markup.strip
+        if LITERALS.key?(markup)
+          LITERALS[markup]
         else
           VariableLookup.parse(markup)
         end

lib/liquid/file_system.rb

@@ -17,7 +17,7 @@ module Liquid
   class BlankFileSystem
     # Called by Liquid to retrieve a template file
     def read_template_file(_template_path)
-      raise FileSystemError, 'This liquid context does not allow includes.'
+      raise FileSystemError, "This liquid context does not allow includes."
     end
   end
 
@@ -46,8 +46,8 @@ module Liquid
   class LocalFileSystem
     attr_accessor :root
 
-    def initialize(root, pattern = '_%s.liquid')
-      @root = root
+    def initialize(root, pattern = "_%s.liquid")
+      @root    = root
       @pattern = pattern
     end
 
@@ -59,7 +59,7 @@ module Liquid
     end
 
     def full_path(template_path)
-      raise FileSystemError, "Illegal template name '#{template_path}'" unless template_path =~ %r{\A[^./][a-zA-Z0-9_/]+\z}
+      raise FileSystemError, "Illegal template name '#{template_path}'" unless %r{\A[^./][a-zA-Z0-9_/]+\z}.match?(template_path)
 
       full_path = if template_path.include?('/')
         File.join(root, File.dirname(template_path), @pattern % File.basename(template_path))

lib/liquid/forloop_drop.rb

@@ -3,13 +3,18 @@
 module Liquid
   class ForloopDrop < Drop
     def initialize(name, length, parentloop)
-      @name = name
-      @length = length
+      @name       = name
+      @length     = length
       @parentloop = parentloop
-      @index = 0
+      @index      = 0
     end
 
-    attr_reader :name, :length, :parentloop
+    attr_reader :length, :parentloop
+
+    def name
+      Usage.increment('forloop_drop_name')
+      @name
+    end
 
     def index
       @index + 1

lib/liquid/i18n.rb

@@ -4,7 +4,7 @@ require 'yaml'
 
 module Liquid
   class I18n
-    DEFAULT_LOCALE = File.join(File.expand_path(__dir__), 'locales', 'en.yml')
+    DEFAULT_LOCALE = File.join(File.expand_path(__dir__), "locales", "en.yml")
 
     TranslationError = Class.new(StandardError)
 

lib/liquid/interrupts.rb

@@ -6,13 +6,13 @@ module Liquid
     attr_reader :message
 
     def initialize(message = nil)
-      @message = message || 'interrupt'
+      @message = message || "interrupt"
     end
   end
 
   # Interrupt that is thrown whenever a {% break %} is called.
-  class BreakInterrupt < RuntimeError; end
+  class BreakInterrupt < Interrupt; end
 
   # Interrupt that is thrown whenever a {% continue %} is called.
-  class ContinueInterrupt < RuntimeError; end
+  class ContinueInterrupt < Interrupt; end
 end

lib/liquid/legacy.rb

@@ -1,79 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  FilterSeparator = FILTER_SEPARATOR
-  ArgumentSeparator = ARGUMENT_SEPARATOR
-  FilterArgumentSeparator = FILTER_ARGUMENT_SEPARATOR
-  VariableAttributeSeparator = VARIABLE_ATTRIBUTE_SEPARATOR
-  WhitespaceControl = WHITESPACE_CONTROL
-  TagStart = TAG_START
-  TagEnd = TAG_END
-  VariableSignature = VARIABLE_SIGNATURE
-  VariableSegment = VARIABLE_SEGMENT
-  VariableStart = VARIABLE_START
-  VariableEnd = VARIABLE_END
-  VariableIncompleteEnd = VARIABLE_INCOMPLETE_END
-  QuotedString = QUOTED_STRING
-  QuotedFragment = QUOTED_FRAGMENT
-  TagAttributes = TAG_ATTRIBUTES
-  AnyStartingTag = ANY_STARTING_TAG
-  PartialTemplateParser = PARTIAL_TEMPLATE_PARSER
-  TemplateParser = TEMPLATE_PARSER
-  VariableParser = VARIABLE_PARSER
-
-  class BlockBody
-    FullToken = FULL_TOKEN
-    ContentOfVariable = CONTENT_OF_VARIABLE
-    WhitespaceOrNothing = WHITESPACE_OR_NOTHING
-    TAGSTART = TAG_START
-    VARSTART = VAR_START
-  end
-
-  class Assign < Tag
-    Syntax = SYNTAX
-  end
-
-  class Capture < Block
-    Syntax = SYNTAX
-  end
-
-  class Case < Block
-    Syntax     = SYNTAX
-    WhenSyntax = WHEN_SYNTAX
-  end
-
-  class Cycle < Tag
-    SimpleSyntax = SIMPLE_SYNTAX
-    NamedSyntax  = NAMED_SYNTAX
-  end
-
-  class For < Block
-    Syntax = SYNTAX
-  end
-
-  class If < Block
-    Syntax = SYNTAX
-    ExpressionsAndOperators = EXPRESSIONS_AND_OPERATORS
-  end
-
-  class Include < Tag
-    Syntax = SYNTAX
-  end
-
-  class Raw < Block
-    Syntax = SYNTAX
-    FullTokenPossiblyInvalid = FULL_TOKEN_POSSIBLY_INVALID
-  end
-
-  class TableRow < Block
-    Syntax = SYNTAX
-  end
-
-  class Variable
-    FilterMarkupRegex = FILTER_MARKUP_REGEX
-    FilterParser = FILTER_PARSER
-    FilterArgsRegex = FILTER_ARGS_REGEX
-    JustTagAttributes = JUST_TAG_ATTRIBUTES
-    MarkupWithQuotedFragment = MARKUP_WITH_QUOTED_FRAGMENT
-  end
-end

lib/liquid/lexer.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require 'strscan'
+require "strscan"
 module Liquid
   class Lexer
     SPECIALS = {
@@ -15,13 +15,13 @@ module Liquid
       '?' => :question,
       '-' => :dash,
     }.freeze
-    IDENTIFIER = /[a-zA-Z_][\w-]*\??/.freeze
-    SINGLE_STRING_LITERAL = /'[^\']*'/.freeze
-    DOUBLE_STRING_LITERAL = /"[^\"]*"/.freeze
-    NUMBER_LITERAL = /-?\d+(\.\d+)?/.freeze
-    DOTDOT = /\.\./.freeze
-    COMPARISON_OPERATOR = /==|!=|<>|<=?|>=?|contains(?=\s)/.freeze
-    WHITESPACE_OR_NOTHING = /\s*/.freeze
+    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)
@@ -33,15 +33,20 @@ module Liquid
       until @ss.eos?
         @ss.skip(WHITESPACE_OR_NOTHING)
         break if @ss.eos?
-
-        tok = if (t = @ss.scan(COMPARISON_OPERATOR)) then [:comparison, t]
-        elsif (t = @ss.scan(SINGLE_STRING_LITERAL)) then [:string, t]
-        elsif (t = @ss.scan(DOUBLE_STRING_LITERAL)) then [:string, t]
-        elsif (t = @ss.scan(NUMBER_LITERAL)) then [:number, t]
-        elsif (t = @ss.scan(IDENTIFIER)) then [:id, t]
-        elsif (t = @ss.scan(DOTDOT)) then [:dotdot, t]
+        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]
         else
-          c = @ss.getch
+          c     = @ss.getch
           if (s = SPECIALS[c])
             [s, c]
           else

lib/liquid/locales/en.yml

@@ -20,7 +20,9 @@
       tag_termination: "Tag '%{token}' was not properly terminated with regexp: %{tag_end}"
       variable_termination: "Variable '%{token}' was not properly terminated with regexp: %{tag_end}"
       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"
+    disabled:
+      tag: "usage is not allowed in this context"

lib/liquid/parse_context.rb

@@ -7,9 +7,11 @@ module Liquid
 
     def initialize(options = {})
       @template_options = options ? options.dup : {}
-      @locale = @template_options[:locale] ||= I18n.new
+
+      @locale   = @template_options[:locale] ||= I18n.new
       @warnings = []
-      self.depth = 0
+
+      self.depth   = 0
       self.partial = false
     end
 
@@ -17,9 +19,22 @@ module Liquid
       @options[option_key]
     end
 
+    def new_block_body
+      Liquid::BlockBody.new
+    end
+
+    def new_tokenizer(markup, start_line_number: nil, for_liquid_tag: false)
+      Tokenizer.new(markup, line_number: start_line_number, for_liquid_tag: for_liquid_tag)
+    end
+
+    def parse_expression(markup)
+      Expression.parse(markup)
+    end
+
     def partial=(value)
       @partial = value
       @options = value ? partial_options : @template_options
+
       @error_mode = @options[:error_mode] || Template.error_mode
     end
 

lib/liquid/parse_tree_visitor.rb

@@ -11,7 +11,7 @@ module Liquid
     end
 
     def initialize(node, callbacks)
-      @node = node
+      @node      = node
       @callbacks = callbacks
     end
 

lib/liquid/parser.rb

@@ -3,9 +3,9 @@
 module Liquid
   class Parser
     def initialize(input)
-      l = Lexer.new(input)
+      l       = Lexer.new(input)
       @tokens = l.tokenize
-      @p = 0 # pointer to current location
+      @p      = 0 # pointer to current location
     end
 
     def jump(point)
@@ -14,8 +14,9 @@ module Liquid
 
     def consume(type = nil)
       token = @tokens[@p]
-      raise SyntaxError, "Expected #{type} but found #{@tokens[@p].first}" if type && token[0] != type
-
+      if type && token[0] != type
+        raise SyntaxError, "Expected #{type} but found #{@tokens[@p].first}"
+      end
       @p += 1
       token[1]
     end
@@ -26,7 +27,6 @@ module Liquid
     def consume?(type)
       token = @tokens[@p]
       return false unless token && token[0] == type
-
       @p += 1
       token[1]
     end
@@ -36,7 +36,6 @@ module Liquid
       token = @tokens[@p]
       return false unless token && token[0] == :id
       return false unless token[1] == str
-
       @p += 1
       token[1]
     end
@@ -44,20 +43,23 @@ module Liquid
     def look(type, ahead = 0)
       tok = @tokens[@p + ahead]
       return false unless tok
-
       tok[0] == type
     end
 
-    SINGLE_TOKEN_EXPRESSION_TYPES = %i[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])
+      case token[0]
+      when :id
+        str = consume
+        str << variable_lookups
+      when :open_square
+        str = consume
+        str << expression
+        str << consume(:close_square)
+        str << variable_lookups
+      when :string, :number
         consume
-      elsif token.first == :open_round
+      when :open_round
         consume
         first = expression
         consume(:dotdot)
@@ -70,24 +72,29 @@ module Liquid
     end
 
     def argument
-      str = +''
+      str = +""
       # might be a keyword argument (identifier: expression)
-      str << consume << consume << ' ' if look(:id) && look(:colon, 1)
+      if look(:id) && look(:colon, 1)
+        str << consume << consume << ' '
+      end
 
       str << expression
       str
     end
 
-    def variable_signature
-      str = consume(:id)
-      while look(:open_square)
-        str << consume
-        str << expression
-        str << consume(:close_square)
-      end
-      if look(:dot)
-        str << consume
-        str << variable_signature
+    def variable_lookups
+      str = +""
+      loop do
+        if look(:open_square)
+          str << consume
+          str << expression
+          str << consume(:close_square)
+        elsif look(:dot)
+          str << consume
+          str << consume(:id)
+        else
+          break
+        end
       end
       str
     end

lib/liquid/parser_switching.rb

@@ -2,16 +2,28 @@
 
 module Liquid
   module ParserSwitching
+    def strict_parse_with_error_mode_fallback(markup)
+      strict_parse_with_error_context(markup)
+    rescue SyntaxError => e
+      case parse_context.error_mode
+      when :strict
+        raise
+      when :warn
+        parse_context.warnings << e
+      end
+      lax_parse(markup)
+    end
+
     def parse_with_selected_parser(markup)
       case parse_context.error_mode
       when :strict then strict_parse_with_error_context(markup)
       when :lax    then lax_parse(markup)
       when :warn
         begin
-          return strict_parse_with_error_context(markup)
+          strict_parse_with_error_context(markup)
         rescue SyntaxError => e
           parse_context.warnings << e
-          return lax_parse(markup)
+          lax_parse(markup)
         end
       end
     end
@@ -21,7 +33,7 @@ module Liquid
     def strict_parse_with_error_context(markup)
       strict_parse(markup)
     rescue SyntaxError => e
-      e.line_number = line_number
+      e.line_number    = line_number
       e.markup_context = markup_context(markup)
       raise e
     end

lib/liquid/partial_cache.rb

@@ -0,0 +1,24 @@
+# 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
+
+      template_factory = (context.registers[:template_factory] ||= Liquid::TemplateFactory.new)
+      template = template_factory.for(template_name)
+
+      partial = template.parse(source, parse_context)
+      cached_partials[template_name] = partial
+    ensure
+      parse_context.partial = false
+    end
+  end
+end

lib/liquid/profiler.rb

@@ -25,7 +25,7 @@ module Liquid
   #     node.code
   #
   #     # Which template and line number of this node.
-  #     # If top level, this will be "<root>".
+  #     # The top-level template name is `nil` by default, but can be set in the Liquid::Context before rendering.
   #     node.partial
   #     node.line_number
   #
@@ -46,115 +46,94 @@ module Liquid
     include Enumerable
 
     class Timing
-      attr_reader :code, :partial, :line_number, :children
+      attr_reader :code, :template_name, :line_number, :children
+      attr_accessor :total_time
+      alias_method :render_time, :total_time
+      alias_method :partial, :template_name
 
-      def initialize(node, partial)
-        @code        = node.respond_to?(:raw) ? node.raw : node
-        @partial     = partial
-        @line_number = node.respond_to?(:line_number) ? node.line_number : nil
-        @children    = []
+      def initialize(code: nil, template_name: nil, line_number: nil)
+        @code = code
+        @template_name = template_name
+        @line_number = line_number
+        @children = []
       end
 
-      def self.start(node, partial)
-        new(node, partial).tap(&:start)
-      end
-
-      def start
-        @start_time = Time.now
-      end
-
-      def finish
-        @end_time = Time.now
-      end
-
-      def render_time
-        @end_time - @start_time
+      def self_time
+        @self_time ||= begin
+          total_children_time = 0.0
+          @children.each do |child|
+            total_children_time += child.total_time
+          end
+          @total_time - total_children_time
+        end
       end
     end
 
-    def self.profile_node_render(node)
-      if Profiler.current_profile && node.respond_to?(:render)
-        Profiler.current_profile.start_node(node)
-        output = yield
-        Profiler.current_profile.end_node(node)
-        output
-      else
-        yield
-      end
-    end
-
-    def self.profile_children(template_name)
-      if Profiler.current_profile
-        Profiler.current_profile.push_partial(template_name)
-        output = yield
-        Profiler.current_profile.pop_partial
-        output
-      else
-        yield
-      end
-    end
-
-    def self.current_profile
-      Thread.current[:liquid_profiler]
-    end
+    attr_reader :total_time
+    alias_method :total_render_time, :total_time
 
     def initialize
-      @partial_stack = ['<root>']
-
-      @root_timing = Timing.new('', current_partial)
-      @timing_stack = [@root_timing]
-
-      @render_start_at = Time.now
-      @render_end_at = @render_start_at
+      @root_children = []
+      @current_children = nil
+      @total_time = 0.0
     end
 
-    def start
-      Thread.current[:liquid_profiler] = self
-      @render_start_at = Time.now
+    def profile(template_name, &block)
+      # nested renders are done from a tag that already has a timing node
+      return yield if @current_children
+
+      root_children = @root_children
+      render_idx = root_children.length
+      begin
+        @current_children = root_children
+        profile_node(template_name, &block)
+      ensure
+        @current_children = nil
+        if (timing = root_children[render_idx])
+          @total_time += timing.total_time
+        end
+      end
     end
 
-    def stop
-      Thread.current[:liquid_profiler] = nil
-      @render_end_at = Time.now
-    end
-
-    def total_render_time
-      @render_end_at - @render_start_at
+    def children
+      children = @root_children
+      if children.length == 1
+        children.first.children
+      else
+        children
+      end
     end
 
     def each(&block)
-      @root_timing.children.each(&block)
+      children.each(&block)
     end
 
     def [](idx)
-      @root_timing.children[idx]
+      children[idx]
     end
 
     def length
-      @root_timing.children.length
+      children.length
     end
 
-    def start_node(node)
-      @timing_stack.push(Timing.start(node, current_partial))
+    def profile_node(template_name, code: nil, line_number: nil)
+      timing = Timing.new(code: code, template_name: template_name, line_number: line_number)
+      parent_children = @current_children
+      start_time = monotonic_time
+      begin
+        @current_children = timing.children
+        yield
+      ensure
+        @current_children = parent_children
+        timing.total_time = monotonic_time - start_time
+        parent_children << timing
+      end
     end
 
-    def end_node(_node)
-      timing = @timing_stack.pop
-      timing.finish
+    private
 
-      @timing_stack.last.children << timing
-    end
-
-    def current_partial
-      @partial_stack.last
-    end
-
-    def push_partial(partial_name)
-      @partial_stack.push(partial_name)
-    end
-
-    def pop_partial
-      @partial_stack.pop
+    def monotonic_time
+      Process.clock_gettime(Process::CLOCK_MONOTONIC)
     end
   end
 end

lib/liquid/profiler/hooks.rb

@@ -1,25 +1,35 @@
 # frozen_string_literal: true
 
 module Liquid
-  class BlockBody
-    def render_node_with_profiling(context, output, node)
-      Profiler.profile_node_render(node) do
-        render_node_without_profiling(context, output, node)
+  module BlockBodyProfilingHook
+    def render_node(context, output, node)
+      if (profiler = context.profiler)
+        profiler.profile_node(context.template_name, code: node.raw, line_number: node.line_number) do
+          super
+        end
+      else
+        super
       end
     end
-
-    alias_method :render_node_without_profiling, :render_node
-    alias_method :render_node, :render_node_with_profiling
   end
+  BlockBody.prepend(BlockBodyProfilingHook)
 
-  class Include < Tag
-    def render_to_output_buffer_with_profiling(context, output)
-      Profiler.profile_children(context.evaluate(@template_name_expr).to_s) do
-        render_to_output_buffer_without_profiling(context, output)
-      end
+  module DocumentProfilingHook
+    def render_to_output_buffer(context, output)
+      return super unless context.profiler
+      context.profiler.profile(context.template_name) { super }
     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
   end
+  Document.prepend(DocumentProfilingHook)
+
+  module ContextProfilingHook
+    attr_accessor :profiler
+
+    def new_isolated_subcontext
+      new_context = super
+      new_context.profiler = profiler
+      new_context
+    end
+  end
+  Context.prepend(ContextProfilingHook)
 end

lib/liquid/range_lookup.rb

@@ -4,7 +4,7 @@ module Liquid
   class RangeLookup
     def self.parse(start_markup, end_markup)
       start_obj = Expression.parse(start_markup)
-      end_obj = Expression.parse(end_markup)
+      end_obj   = Expression.parse(end_markup)
       if start_obj.respond_to?(:evaluate) || end_obj.respond_to?(:evaluate)
         new(start_obj, end_obj)
       else
@@ -14,12 +14,12 @@ module Liquid
 
     def initialize(start_obj, end_obj)
       @start_obj = start_obj
-      @end_obj = end_obj
+      @end_obj   = end_obj
     end
 
     def evaluate(context)
       start_int = to_integer(context.evaluate(@start_obj))
-      end_int = to_integer(context.evaluate(@end_obj))
+      end_int   = to_integer(context.evaluate(@end_obj))
       start_int..end_int
     end
 

lib/liquid/register.rb

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+module Liquid
+  class Register
+  end
+end

lib/liquid/resource_limits.rb

@@ -2,24 +2,61 @@
 
 module Liquid
   class ResourceLimits
-    attr_accessor :render_length, :render_score, :assign_score,
-                  :render_length_limit, :render_score_limit, :assign_score_limit
+    attr_accessor :render_length_limit, :render_score_limit, :assign_score_limit
+    attr_reader :render_score, :assign_score
 
     def initialize(limits)
       @render_length_limit = limits[:render_length_limit]
-      @render_score_limit = limits[:render_score_limit]
-      @assign_score_limit = limits[:assign_score_limit]
+      @render_score_limit  = limits[:render_score_limit]
+      @assign_score_limit  = limits[:assign_score_limit]
       reset
     end
 
+    def increment_render_score(amount)
+      @render_score += amount
+      raise_limits_reached if @render_score_limit && @render_score > @render_score_limit
+    end
+
+    def increment_assign_score(amount)
+      @assign_score += amount
+      raise_limits_reached if @assign_score_limit && @assign_score > @assign_score_limit
+    end
+
+    # update either render_length or assign_score based on whether or not the writes are captured
+    def increment_write_score(output)
+      if (last_captured = @last_capture_length)
+        captured = output.bytesize
+        increment = captured - last_captured
+        @last_capture_length = captured
+        increment_assign_score(increment)
+      elsif @render_length_limit && output.bytesize > @render_length_limit
+        raise_limits_reached
+      end
+    end
+
+    def raise_limits_reached
+      @reached_limit = true
+      raise MemoryError, "Memory limits exceeded"
+    end
+
     def reached?
-      (@render_length_limit && @render_length > @render_length_limit) ||
-        (@render_score_limit && @render_score > @render_score_limit) ||
-        (@assign_score_limit && @assign_score > @assign_score_limit)
+      @reached_limit
     end
 
     def reset
-      @render_length = @render_score = @assign_score = 0
+      @reached_limit = false
+      @last_capture_length = nil
+      @render_score = @assign_score = 0
+    end
+
+    def with_capture
+      old_capture_length = @last_capture_length
+      begin
+        @last_capture_length = 0
+        yield
+      ensure
+        @last_capture_length = old_capture_length
+      end
     end
   end
 end

lib/liquid/standardfilters.rb

@@ -12,13 +12,13 @@ module Liquid
       '"' => '"',
       "'" => ''',
     }.freeze
-    HTML_ESCAPE_ONCE_REGEXP = /["><']|&(?!([a-zA-Z]+|(#\d+));)/.freeze
-    STRIP_HTML_BLOCKS = Regexp.union(
+    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.freeze
+    STRIP_HTML_TAGS = /<.*?>/m
 
     # Return the size of an array or of an string
     def size(input)
@@ -41,7 +41,7 @@ module Liquid
     end
 
     def escape(input)
-      CGI.escapeHTML(input.to_s).untaint unless input.nil?
+      CGI.escapeHTML(input.to_s) unless input.nil?
     end
     alias_method :h, :escape
 
@@ -74,25 +74,30 @@ module Liquid
     end
 
     # Truncate a string down to x characters
-    def truncate(input, length = 50, truncate_string = '...')
+    def truncate(input, length = 50, truncate_string = "...")
       return if input.nil?
-
       input_str = input.to_s
-      length = Utils.to_integer(length)
+      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
     end
 
-    def truncatewords(input, words = 15, truncate_string = '...')
+    def truncatewords(input, words = 15, truncate_string = "...")
       return if input.nil?
-
-      wordlist = input.to_s.split
+      input = input.to_s
       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
+      words = 1 if words <= 0
+
+      wordlist = input.split(" ", words + 1)
+      return input if wordlist.length <= words
+
+      wordlist.pop
+      wordlist.join(" ").concat(truncate_string.to_s)
     end
 
     # Split input string into an array of substrings separated by given pattern.
@@ -117,7 +122,7 @@ module Liquid
     end
 
     def strip_html(input)
-      empty = ''
+      empty  = ''
       result = input.to_s.gsub(STRIP_HTML_BLOCKS, empty)
       result.gsub!(STRIP_HTML_TAGS, empty)
       result
@@ -130,13 +135,13 @@ module Liquid
 
     # Join elements of the array with certain character between them
     def join(input, glue = ' ')
-      InputIterator.new(input).join(glue)
+      InputIterator.new(input, context).join(glue)
     end
 
     # Sort elements of the array
     # provide optional property with which to sort an array of hashes or drops
     def sort(input, property = nil)
-      ary = InputIterator.new(input)
+      ary = InputIterator.new(input, context)
 
       return [] if ary.empty?
 
@@ -156,7 +161,7 @@ module Liquid
     # Sort elements of an array ignoring case if strings
     # provide optional property with which to sort an array of hashes or drops
     def sort_natural(input, property = nil)
-      ary = InputIterator.new(input)
+      ary = InputIterator.new(input, context)
 
       return [] if ary.empty?
 
@@ -176,7 +181,7 @@ module Liquid
     # 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)
+      ary = InputIterator.new(input, context)
 
       if ary.empty?
         []
@@ -198,7 +203,7 @@ module Liquid
     # Remove duplicate elements from an array
     # provide optional property with which to determine uniqueness
     def uniq(input, property = nil)
-      ary = InputIterator.new(input)
+      ary = InputIterator.new(input, context)
 
       if property.nil?
         ary.uniq
@@ -215,16 +220,16 @@ module Liquid
 
     # Reverse the elements of an array
     def reverse(input)
-      ary = InputIterator.new(input)
+      ary = InputIterator.new(input, context)
       ary.reverse
     end
 
     # map/collect on a given property
     def map(input, property)
-      InputIterator.new(input).map do |e|
+      InputIterator.new(input, context).map do |e|
         e = e.call if e.is_a?(Proc)
 
-        if property == 'to_liquid'
+        if property == "to_liquid"
           e
         elsif e.respond_to?(:[])
           r = e[property]
@@ -238,7 +243,7 @@ module Liquid
     # Remove nils within an array
     # provide optional property with which to check for nil
     def compact(input, property = nil)
-      ary = InputIterator.new(input)
+      ary = InputIterator.new(input, context)
 
       if property.nil?
         ary.compact
@@ -279,9 +284,10 @@ module Liquid
     end
 
     def concat(input, array)
-      raise ArgumentError, 'concat filter requires an array argument' unless array.respond_to?(:to_ary)
-
-      InputIterator.new(input).concat(array)
+      unless array.respond_to?(:to_ary)
+        raise ArgumentError, "concat filter requires an array argument"
+      end
+      InputIterator.new(input, context).concat(array)
     end
 
     # prepend a string to another
@@ -291,7 +297,7 @@ 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(/\r?\n/, "<br />\n")
     end
 
     # Reformat a date using Ruby's core Time#strftime( string ) -> string
@@ -422,16 +428,26 @@ module Liquid
       result.is_a?(BigDecimal) ? result.to_f : result
     end
 
-    def default(input, default_value = '')
-      if !input || input.respond_to?(:empty?) && input.empty?
-        default_value
-      else
-        input
-      end
+    # Set a default value when the input is nil, false or empty
+    #
+    # Example:
+    #    {{ product.title | default: "No Title" }}
+    #
+    # Use `allow_false` when an input should only be tested against nil or empty and not false.
+    #
+    # Example:
+    #    {{ product.title | default: "No Title", allow_false: true }}
+    #
+    def default(input, default_value = '', options = {})
+      options = {} unless options.is_a?(Hash)
+      false_check = options['allow_false'] ? input.nil? : !input
+      false_check || (input.respond_to?(:empty?) && input.empty?) ? default_value : input
     end
 
     private
 
+    attr_reader :context
+
     def raise_property_error(property)
       raise Liquid::ArgumentError, "cannot select the property '#{property}'"
     end
@@ -460,8 +476,9 @@ module Liquid
     class InputIterator
       include Enumerable
 
-      def initialize(input)
-        @input = if input.is_a?(Array)
+      def initialize(input, context)
+        @context = context
+        @input   = if input.is_a?(Array)
           input.flatten
         elsif input.is_a?(Hash)
           [input]
@@ -499,6 +516,7 @@ module Liquid
 
       def each
         @input.each do |e|
+          e.context = @context if e.respond_to?(:context=)
           yield(e.respond_to?(:to_liquid) ? e.to_liquid : e)
         end
       end

lib/liquid/static_registers.rb

@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+module Liquid
+  class StaticRegisters
+    attr_reader :static
+
+    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
+
+    UNDEFINED = Object.new
+
+    def fetch(key, default = UNDEFINED, &block)
+      if @registers.key?(key)
+        @registers.fetch(key)
+      elsif default != UNDEFINED
+        @static.fetch(key, default, &block)
+      else
+        @static.fetch(key, &block)
+      end
+    end
+
+    def key?(key)
+      @registers.key?(key) || @static.key?(key)
+    end
+  end
+end

lib/liquid/strainer.rb

@@ -1,70 +0,0 @@
-# frozen_string_literal: true
-
-require 'set'
-
-module Liquid
-  # Strainer is the parent class for the filters system.
-  # New filters are mixed into the strainer class which is then instantiated for each liquid template render run.
-  #
-  # The Strainer only allows method calls defined in filters given to it via Strainer.global_filter,
-  # Context#add_filters or Template.register_filter
-  class Strainer #:nodoc:
-    @global_strainer = Class.new(Strainer) do
-      @filter_methods = Set.new
-    end
-    @strainer_class_cache = Hash.new do |hash, filters|
-      hash[filters] = Class.new(@global_strainer) do
-        @filter_methods = Strainer.global_strainer.filter_methods.dup
-        filters.each { |f| add_filter(f) }
-      end
-    end
-
-    def initialize(context)
-      @context = context
-    end
-
-    class << self
-      attr_accessor :strainer_class_cache, :global_strainer
-      attr_reader :filter_methods
-    end
-
-    def self.add_filter(filter)
-      raise ArgumentError, "Expected module but got: #{filter.class}" unless filter.is_a?(Module)
-
-      unless include?(filter)
-        invokable_non_public_methods = (filter.private_instance_methods + filter.protected_instance_methods).select { |m| invokable?(m) }
-        if invokable_non_public_methods.any?
-          raise MethodOverrideError, "Filter overrides registered public methods as non public: #{invokable_non_public_methods.join(', ')}"
-        else
-          send(:include, filter)
-          @filter_methods.merge(filter.public_instance_methods.map(&:to_s))
-        end
-      end
-    end
-
-    def self.global_filter(filter)
-      @strainer_class_cache.clear
-      @global_strainer.add_filter(filter)
-    end
-
-    def self.invokable?(method)
-      @filter_methods.include?(method.to_s)
-    end
-
-    def self.create(context, filters = [])
-      @strainer_class_cache[filters].new(context)
-    end
-
-    def invoke(method, *args)
-      if self.class.invokable?(method)
-        send(method, *args)
-      elsif @context&.strict_filters
-        raise Liquid::UndefinedFilter, "undefined filter #{method}"
-      else
-        args.first
-      end
-    rescue ::ArgumentError => e
-      raise Liquid::ArgumentError, e.message, e.backtrace
-    end
-  end
-end

lib/liquid/strainer_factory.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+module Liquid
+  # StrainerFactory is the factory for the filters system.
+  module StrainerFactory
+    extend self
+
+    def add_global_filter(filter)
+      strainer_class_cache.clear
+      global_filters << filter
+    end
+
+    def create(context, filters = [])
+      strainer_from_cache(filters).new(context)
+    end
+
+    private
+
+    def global_filters
+      @global_filters ||= []
+    end
+
+    def strainer_from_cache(filters)
+      strainer_class_cache[filters] ||= begin
+        klass = Class.new(StrainerTemplate)
+        global_filters.each { |f| klass.add_filter(f) }
+        filters.each { |f| klass.add_filter(f) }
+        klass
+      end
+    end
+
+    def strainer_class_cache
+      @strainer_class_cache ||= {}
+    end
+  end
+end

lib/liquid/strainer_template.rb

@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+require 'set'
+
+module Liquid
+  # StrainerTemplate is the computed class for the filters system.
+  # New filters are mixed into the strainer class which is then instantiated for each liquid template render run.
+  #
+  # The Strainer only allows method calls defined in filters given to it via StrainerFactory.add_global_filter,
+  # Context#add_filters or Template.register_filter
+  class StrainerTemplate
+    def initialize(context)
+      @context = context
+    end
+
+    class << self
+      def add_filter(filter)
+        return if 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(', ')}"
+        end
+
+        include(filter)
+
+        filter_methods.merge(filter.public_instance_methods.map(&:to_s))
+      end
+
+      def invokable?(method)
+        filter_methods.include?(method.to_s)
+      end
+
+      private
+
+      def filter_methods
+        @filter_methods ||= Set.new
+      end
+    end
+
+    def invoke(method, *args)
+      if self.class.invokable?(method)
+        send(method, *args)
+      elsif @context.strict_filters
+        raise Liquid::UndefinedFilter, "undefined filter #{method}"
+      else
+        args.first
+      end
+    rescue ::ArgumentError => e
+      raise Liquid::ArgumentError, e.message, e.backtrace
+    end
+  end
+end

lib/liquid/tablerowloop_drop.rb

@@ -4,10 +4,10 @@ module Liquid
   class TablerowloopDrop < Drop
     def initialize(length, cols)
       @length = length
-      @row = 1
-      @col = 1
-      @cols = cols
-      @index = 0
+      @row    = 1
+      @col    = 1
+      @cols   = cols
+      @index  = 0
     end
 
     attr_reader :length, :col, :row

lib/liquid/tag.rb

@@ -7,23 +7,30 @@ module Liquid
     include ParserSwitching
 
     class << self
-      def parse(tag_name, markup, tokenizer, options)
-        tag = new(tag_name, markup, options)
+      def parse(tag_name, markup, tokenizer, parse_context)
+        tag = new(tag_name, markup, parse_context)
         tag.parse(tokenizer)
         tag
       end
 
+      def disable_tags(*tag_names)
+        @disabled_tags ||= []
+        @disabled_tags.concat(tag_names)
+        prepend(Disabler)
+      end
+
       private :new
     end
 
     def initialize(tag_name, markup, parse_context)
-      @tag_name   = tag_name
-      @markup     = markup
+      @tag_name      = tag_name
+      @markup        = markup
       @parse_context = parse_context
-      @line_number = parse_context.line_number
+      @line_number   = parse_context.line_number
     end
 
-    def parse(_tokens); end
+    def parse(_tokens)
+    end
 
     def raw
       "#{@tag_name} #{@markup}"
@@ -48,5 +55,11 @@ module Liquid
     def blank?
       false
     end
+
+    private
+
+    def parse_expression(markup)
+      parse_context.parse_expression(markup)
+    end
   end
 end

lib/liquid/tag/disableable.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+module Liquid
+  class Tag
+    module Disableable
+      def render_to_output_buffer(context, output)
+        if context.tag_disabled?(tag_name)
+          output << disabled_error(context)
+          return
+        end
+        super
+      end
+
+      def disabled_error(context)
+        # raise then rescue the exception so that the Context#exception_renderer can re-raise it
+        raise DisabledError, "#{tag_name} #{parse_context[:locale].t('errors.disabled.tag')}"
+      rescue DisabledError => exc
+        context.handle_error(exc, line_number)
+      end
+    end
+  end
+end

lib/liquid/tag/disabler.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+module Liquid
+  class Tag
+    module Disabler
+      module ClassMethods
+        attr_reader :disabled_tags
+      end
+
+      def self.prepended(base)
+        base.extend(ClassMethods)
+      end
+
+      def render_to_output_buffer(context, output)
+        context.with_disabled_tags(self.class.disabled_tags) do
+          super
+        end
+      end
+    end
+  end
+end

lib/liquid/tags/assign.rb

@@ -10,24 +10,29 @@ module Liquid
   #  {{ foo }}
   #
   class Assign < Tag
-    SYNTAX = /(#{VARIABLE_SIGNATURE}+)\s*=\s*(.*)\s*/om.freeze
+    Syntax = /(#{VariableSignature}+)\s*=\s*(.*)\s*/om
+
+    # @api private
+    def self.raise_syntax_error(parse_context)
+      raise Liquid::SyntaxError, parse_context.locale.t('errors.syntax.assign')
+    end
 
     attr_reader :to, :from
 
-    def initialize(tag_name, markup, options)
+    def initialize(tag_name, markup, parse_context)
       super
-      if markup =~ SYNTAX
-        @to = Regexp.last_match(1)
-        @from = Variable.new(Regexp.last_match(2), options)
+      if markup =~ Syntax
+        @to   = Regexp.last_match(1)
+        @from = Variable.new(Regexp.last_match(2), parse_context)
       else
-        raise SyntaxError, options[:locale].t('errors.syntax.assign')
+        self.class.raise_syntax_error(parse_context)
       end
     end
 
     def render_to_output_buffer(context, output)
       val = @from.render(context)
       context.scopes.last[@to] = val
-      context.resource_limits.assign_score += assign_score_of(val)
+      context.resource_limits.increment_assign_score(assign_score_of(val))
       output
     end
 
@@ -40,11 +45,18 @@ module Liquid
     def assign_score_of(val)
       if val.instance_of?(String)
         val.bytesize
-      elsif val.instance_of?(Array) || val.instance_of?(Hash)
+      elsif val.instance_of?(Array)
         sum = 1
         # Uses #each to avoid extra allocations.
         val.each { |child| sum += assign_score_of(child) }
         sum
+      elsif val.instance_of?(Hash)
+        sum = 1
+        val.each do |key, entry_value|
+          sum += assign_score_of(key)
+          sum += assign_score_of(entry_value)
+        end
+        sum
       else
         1
       end

lib/liquid/tags/break.rb

@@ -11,8 +11,11 @@ module Liquid
   #    {% endfor %}
   #
   class Break < Tag
-    def interrupt
-      BreakInterrupt.new
+    INTERRUPT = BreakInterrupt.new.freeze
+
+    def render_to_output_buffer(context, output)
+      context.push_interrupt(INTERRUPT)
+      output
     end
   end
 

lib/liquid/tags/capture.rb

@@ -13,22 +13,22 @@ module Liquid
   # in a sidebar or footer.
   #
   class Capture < Block
-    SYNTAX = /(#{VARIABLE_SIGNATURE}+)/o.freeze
+    Syntax = /(#{VariableSignature}+)/o
 
     def initialize(tag_name, markup, options)
       super
-      if markup =~ SYNTAX
+      if markup =~ Syntax
         @to = Regexp.last_match(1)
       else
-        raise SyntaxError, options[:locale].t('errors.syntax.capture')
+        raise SyntaxError, options[:locale].t("errors.syntax.capture")
       end
     end
 
     def render_to_output_buffer(context, output)
-      previous_output_size = output.bytesize
-      super
-      context.scopes.last[@to] = output
-      context.resource_limits.assign_score += (output.bytesize - previous_output_size)
+      context.resource_limits.with_capture do
+        capture_output = render(context)
+        context.scopes.last[@to] = capture_output
+      end
       output
     end
 

lib/liquid/tags/case.rb

@@ -2,8 +2,8 @@
 
 module Liquid
   class Case < Block
-    SYNTAX = /(#{QUOTED_FRAGMENT})/o.freeze
-    WHEN_SYNTAX = /(#{QUOTED_FRAGMENT})(?:(?:\s+or\s+|\s*\,\s*)(#{QUOTED_FRAGMENT}.*))?/om.freeze
+    Syntax     = /(#{QuotedFragment})/o
+    WhenSyntax = /(#{QuotedFragment})(?:(?:\s+or\s+|\s*\,\s*)(#{QuotedFragment}.*))?/om
 
     attr_reader :blocks, :left
 
@@ -11,16 +11,24 @@ module Liquid
       super
       @blocks = []
 
-      if markup =~ SYNTAX
-        @left = Expression.parse(Regexp.last_match(1))
+      if markup =~ Syntax
+        @left = parse_expression(Regexp.last_match(1))
       else
-        raise SyntaxError, options[:locale].t('errors.syntax.case')
+        raise SyntaxError, options[:locale].t("errors.syntax.case")
       end
     end
 
     def parse(tokens)
-      body = BlockBody.new
+      body = case_body = new_body
       body = @blocks.last.attachment while parse_body(body, tokens)
+      @blocks.reverse_each do |condition|
+        body = condition.attachment
+        unless body.frozen?
+          body.remove_blank_strings if blank?
+          body.freeze
+        end
+      end
+      case_body.freeze
     end
 
     def nodelist
@@ -39,16 +47,14 @@ module Liquid
     end
 
     def render_to_output_buffer(context, output)
-      context.stack do
-        execute_else_block = true
+      execute_else_block = true
 
-        @blocks.each do |block|
-          if block.else?
-            block.attachment.render_to_output_buffer(context, output) if execute_else_block
-          elsif block.evaluate(context)
-            execute_else_block = false
-            block.attachment.render_to_output_buffer(context, output)
-          end
+      @blocks.each do |block|
+        if block.else?
+          block.attachment.render_to_output_buffer(context, output) if execute_else_block
+        elsif block.evaluate(context)
+          execute_else_block = false
+          block.attachment.render_to_output_buffer(context, output)
         end
       end
 
@@ -58,24 +64,28 @@ module Liquid
     private
 
     def record_when_condition(markup)
-      body = BlockBody.new
+      body = new_body
 
       while markup
-        raise SyntaxError, options[:locale].t('errors.syntax.case_invalid_when') unless markup =~ WHEN_SYNTAX
+        unless markup =~ WhenSyntax
+          raise SyntaxError, options[:locale].t("errors.syntax.case_invalid_when")
+        end
 
         markup = Regexp.last_match(2)
 
-        block = Condition.new(@left, '==', Expression.parse(Regexp.last_match(1)))
+        block = Condition.new(@left, '==', Condition.parse_expression(parse_context, Regexp.last_match(1)))
         block.attach(body)
         @blocks << block
       end
     end
 
     def record_else_condition(markup)
-      raise SyntaxError, options[:locale].t('errors.syntax.case_invalid_else') unless markup.strip.empty?
+      unless markup.strip.empty?
+        raise SyntaxError, options[:locale].t("errors.syntax.case_invalid_else")
+      end
 
       block = ElseCondition.new
-      block.attach(BlockBody.new)
+      block.attach(new_body)
       @blocks << block
     end
 

lib/liquid/tags/comment.rb

@@ -6,7 +6,8 @@ module Liquid
       output
     end
 
-    def unknown_tag(_tag, _markup, _tokens); end
+    def unknown_tag(_tag, _markup, _tokens)
+    end
 
     def blank?
       true

lib/liquid/tags/continue.rb

@@ -11,8 +11,11 @@ module Liquid
   #    {% endfor %}
   #
   class Continue < Tag
-    def interrupt
-      ContinueInterrupt.new
+    INTERRUPT = ContinueInterrupt.new.freeze
+
+    def render_to_output_buffer(context, output)
+      context.push_interrupt(INTERRUPT)
+      output
     end
   end
 

lib/liquid/tags/cycle.rb

@@ -14,47 +14,45 @@ module Liquid
   #    <div class="green"> Item five</div>
   #
   class Cycle < Tag
-    SIMPLE_SYNTAX = /\A#{QUOTED_FRAGMENT}+/o.freeze
-    NAMED_SYNTAX  = /\A(#{QUOTED_FRAGMENT})\s*\:\s*(.*)/om.freeze
+    SimpleSyntax = /\A#{QuotedFragment}+/o
+    NamedSyntax  = /\A(#{QuotedFragment})\s*\:\s*(.*)/om
 
     attr_reader :variables
 
     def initialize(tag_name, markup, options)
       super
       case markup
-      when NAMED_SYNTAX
+      when NamedSyntax
         @variables = variables_from_string(Regexp.last_match(2))
-        @name = Expression.parse(Regexp.last_match(1))
-      when SIMPLE_SYNTAX
+        @name      = parse_expression(Regexp.last_match(1))
+      when SimpleSyntax
         @variables = variables_from_string(markup)
-        @name = @variables.to_s
+        @name      = @variables.to_s
       else
-        raise SyntaxError, options[:locale].t('errors.syntax.cycle')
+        raise SyntaxError, options[:locale].t("errors.syntax.cycle")
       end
     end
 
     def render_to_output_buffer(context, output)
       context.registers[:cycle] ||= {}
 
-      context.stack do
-        key = context.evaluate(@name)
-        iteration = context.registers[:cycle][key].to_i
+      key       = context.evaluate(@name)
+      iteration = context.registers[:cycle][key].to_i
 
-        val = context.evaluate(@variables[iteration])
+      val = context.evaluate(@variables[iteration])
 
-        if val.is_a?(Array)
-          val = val.join
-        elsif !val.is_a?(String)
-          val = val.to_s
-        end
-
-        output << val
-
-        iteration += 1
-        iteration  = 0 if iteration >= @variables.size
-        context.registers[:cycle][key] = iteration
+      if val.is_a?(Array)
+        val = val.join
+      elsif !val.is_a?(String)
+        val = val.to_s
       end
 
+      output << val
+
+      iteration += 1
+      iteration = 0 if iteration >= @variables.size
+
+      context.registers[:cycle][key] = iteration
       output
     end
 
@@ -62,8 +60,8 @@ module Liquid
 
     def variables_from_string(markup)
       markup.split(',').collect do |var|
-        var =~ /\s*(#{QUOTED_FRAGMENT})\s*/o
-        Regexp.last_match(1) ? Expression.parse(Regexp.last_match(1)) : nil
+        var =~ /\s*(#{QuotedFragment})\s*/o
+        Regexp.last_match(1) ? parse_expression(Regexp.last_match(1)) : nil
       end.compact
     end
 

lib/liquid/tags/echo.rb

@@ -0,0 +1,34 @@
+# 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
+    attr_reader :variable
+
+    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
+
+    class ParseTreeVisitor < Liquid::ParseTreeVisitor
+      def children
+        [@node.variable]
+      end
+    end
+  end
+
+  Template.register_tag('echo', Echo)
+end

lib/liquid/tags/for.rb

@@ -46,7 +46,7 @@ module Liquid
   # forloop.parentloop:: Provides access to the parent loop, if present.
   #
   class For < Block
-    SYNTAX = /\A(#{VARIABLE_SEGMENT}+)\s+in\s+(#{QUOTED_FRAGMENT}+)\s*(reversed)?/o.freeze
+    Syntax = /\A(#{VariableSegment}+)\s+in\s+(#{QuotedFragment}+)\s*(reversed)?/o
 
     attr_reader :collection_name, :variable_name, :limit, :from
 
@@ -54,14 +54,20 @@ module Liquid
       super
       @from = @limit = nil
       parse_with_selected_parser(markup)
-      @for_block = BlockBody.new
+      @for_block = new_body
       @else_block = nil
     end
 
     def parse(tokens)
-      return unless parse_body(@for_block, tokens)
-
-      parse_body(@else_block, tokens)
+      if parse_body(@for_block, tokens)
+        parse_body(@else_block, tokens)
+      end
+      if blank?
+        @else_block&.remove_blank_strings
+        @for_block.remove_blank_strings
+      end
+      @else_block&.freeze
+      @for_block.freeze
     end
 
     def nodelist
@@ -70,8 +76,7 @@ module Liquid
 
     def unknown_tag(tag, markup, tokens)
       return super unless tag == 'else'
-
-      @else_block = BlockBody.new
+      @else_block = new_body
     end
 
     def render_to_output_buffer(context, output)
@@ -89,35 +94,35 @@ module Liquid
     protected
 
     def lax_parse(markup)
-      if markup =~ SYNTAX
-        @variable_name = Regexp.last_match(1)
-        collection_name = Regexp.last_match(2)
-        @reversed = !!Regexp.last_match(3)
-        @name = "#{@variable_name}-#{collection_name}"
-        @collection_name = Expression.parse(collection_name)
-        markup.scan(TAG_ATTRIBUTES) do |key, value|
+      if markup =~ Syntax
+        @variable_name   = Regexp.last_match(1)
+        collection_name  = Regexp.last_match(2)
+        @reversed        = !!Regexp.last_match(3)
+        @name            = "#{@variable_name}-#{collection_name}"
+        @collection_name = parse_expression(collection_name)
+        markup.scan(TagAttributes) do |key, value|
           set_attribute(key, value)
         end
       else
-        raise SyntaxError, options[:locale].t('errors.syntax.for')
+        raise SyntaxError, options[:locale].t("errors.syntax.for")
       end
     end
 
     def strict_parse(markup)
       p = Parser.new(markup)
       @variable_name = p.consume(:id)
-      raise SyntaxError, options[:locale].t('errors.syntax.for_invalid_in') unless p.id?('in')
+      raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_in") unless p.id?('in')
 
-      collection_name = p.expression
-      @name = "#{@variable_name}-#{collection_name}"
-      @collection_name = Expression.parse(collection_name)
+      collection_name  = p.expression
+      @collection_name = parse_expression(collection_name)
+
+      @name     = "#{@variable_name}-#{collection_name}"
       @reversed = p.id?('reversed')
 
       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')
+          raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_attribute")
         end
-
         p.consume
         set_attribute(attribute, p.expression)
       end
@@ -160,7 +165,7 @@ module Liquid
 
     def render_segment(context, output, segment)
       for_stack = context.registers[:for_stack] ||= []
-      length = segment.length
+      length    = segment.length
 
       context.stack do
         loop_vars = Liquid::ForloopDrop.new(@name, length, for_stack[-1])
@@ -177,7 +182,6 @@ module Liquid
 
             # 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)
@@ -194,12 +198,13 @@ module Liquid
       case key
       when 'offset'
         @from = if expr == 'continue'
+          Usage.increment('for_offset_continue')
           :continue
         else
-          Expression.parse(expr)
+          parse_expression(expr)
         end
       when 'limit'
-        @limit = Expression.parse(expr)
+        @limit = parse_expression(expr)
       end
     end
 

lib/liquid/tags/if.rb

@@ -12,9 +12,9 @@ module Liquid
   #    There are {% if count < 5 %} less {% else %} more {% endif %} items than you need.
   #
   class If < Block
-    SYNTAX = /(#{QUOTED_FRAGMENT})\s*([=!<>a-z_]+)?\s*(#{QUOTED_FRAGMENT})?/o.freeze
-    EXPRESSIONS_AND_OPERATORS = /(?:\b(?:\s?and\s?|\s?or\s?)\b|(?:\s*(?!\b(?:\s?and\s?|\s?or\s?)\b)(?:#{QUOTED_FRAGMENT}|\S+)\s*)+)/o.freeze
-    BOOLEAN_OPERATORS = %w[and or].freeze
+    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
 
@@ -31,10 +31,17 @@ module Liquid
     def parse(tokens)
       while parse_body(@blocks.last.attachment, tokens)
       end
+      @blocks.reverse_each do |block|
+        block.attachment.remove_blank_strings if blank?
+        block.attachment.freeze
+      end
     end
 
+    ELSE_TAG_NAMES = ['elsif', 'else'].freeze
+    private_constant :ELSE_TAG_NAMES
+
     def unknown_tag(tag, markup, tokens)
-      if %w[elsif else].include?(tag)
+      if ELSE_TAG_NAMES.include?(tag)
         push_block(tag, markup)
       else
         super
@@ -42,9 +49,9 @@ module Liquid
     end
 
     def render_to_output_buffer(context, output)
-      context.stack do
-        @blocks.each do |block|
-          return block.attachment.render_to_output_buffer(context, output) if block.evaluate(context)
+      @blocks.each do |block|
+        if block.evaluate(context)
+          return block.attachment.render_to_output_buffer(context, output)
         end
       end
 
@@ -61,23 +68,26 @@ module Liquid
       end
 
       @blocks.push(block)
-      block.attach(BlockBody.new)
+      block.attach(new_body)
+    end
+
+    def parse_expression(markup)
+      Condition.parse_expression(parse_context, markup)
     end
 
     def lax_parse(markup)
-      expressions = markup.scan(EXPRESSIONS_AND_OPERATORS)
-      raise SyntaxError, options[:locale].t('errors.syntax.if') unless expressions.pop =~ SYNTAX
+      expressions = markup.scan(ExpressionsAndOperators)
+      raise SyntaxError, options[:locale].t("errors.syntax.if") 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(parse_expression(Regexp.last_match(1)), Regexp.last_match(2), parse_expression(Regexp.last_match(3)))
 
       until expressions.empty?
         operator = expressions.pop.to_s.strip
 
-        raise SyntaxError, options[:locale].t('errors.syntax.if') unless expressions.pop.to_s =~ SYNTAX
-
-        new_condition = Condition.new(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)
+        raise SyntaxError, options[:locale].t("errors.syntax.if") unless expressions.pop.to_s =~ Syntax
 
+        new_condition = Condition.new(parse_expression(Regexp.last_match(1)), Regexp.last_match(2), parse_expression(Regexp.last_match(3)))
+        raise SyntaxError, options[:locale].t("errors.syntax.if") unless BOOLEAN_OPERATORS.include?(operator)
         new_condition.send(operator, condition)
         condition = new_condition
       end
@@ -104,9 +114,9 @@ module Liquid
     end
 
     def parse_comparison(p)
-      a = Expression.parse(p.expression)
+      a = parse_expression(p.expression)
       if (op = p.consume?(:comparison))
-        b = Expression.parse(p.expression)
+        b = parse_expression(p.expression)
         Condition.new(a, op, b)
       else
         Condition.new(a)

lib/liquid/tags/ifchanged.rb

@@ -3,14 +3,12 @@
 module Liquid
   class Ifchanged < Block
     def render_to_output_buffer(context, output)
-      context.stack do
-        block_output = +''
-        super(context, block_output)
+      block_output = +''
+      super(context, block_output)
 
-        if block_output != context.registers[:ifchanged]
-          context.registers[:ifchanged] = block_output
-          output << block_output
-        end
+      if block_output != context.registers[:ifchanged]
+        context.registers[:ifchanged] = block_output
+        output << block_output
       end
 
       output

lib/liquid/tags/include.rb

@@ -16,7 +16,10 @@ module Liquid
   #   {% include 'product' for products %}
   #
   class Include < Tag
-    SYNTAX = /(#{QUOTED_FRAGMENT}+)(\s+(?:with|for)\s+(#{QUOTED_FRAGMENT}+))?/o.freeze
+    prepend Tag::Disableable
+
+    SYNTAX = /(#{QuotedFragment}+)(\s+(?:with|for)\s+(#{QuotedFragment}+))?(\s+(?:as)\s+(#{VariableSegment}+))?/o
+    Syntax = SYNTAX
 
     attr_reader :template_name_expr, :variable_name_expr, :attributes
 
@@ -28,27 +31,34 @@ module Liquid
         template_name = Regexp.last_match(1)
         variable_name = Regexp.last_match(3)
 
-        @variable_name_expr = variable_name ? Expression.parse(variable_name) : nil
-        @template_name_expr = Expression.parse(template_name)
-        @attributes = {}
+        @alias_name         = Regexp.last_match(5)
+        @variable_name_expr = variable_name ? parse_expression(variable_name) : nil
+        @template_name_expr = parse_expression(template_name)
+        @attributes         = {}
 
-        markup.scan(TAG_ATTRIBUTES) do |key, value|
-          @attributes[key] = Expression.parse(value)
+        markup.scan(TagAttributes) do |key, value|
+          @attributes[key] = parse_expression(value)
         end
 
       else
-        raise SyntaxError, options[:locale].t('errors.syntax.include')
+        raise SyntaxError, options[:locale].t("errors.syntax.include")
       end
     end
 
-    def parse(_tokens); end
+    def parse(_tokens)
+    end
 
     def render_to_output_buffer(context, output)
       template_name = context.evaluate(@template_name_expr)
-      raise ArgumentError, options[:locale].t('errors.argument.include') unless template_name
+      raise ArgumentError, options[:locale].t("errors.argument.include") unless template_name
 
-      partial = load_cached_partial(template_name, context)
-      context_variable_name = template_name.split('/').last
+      partial = PartialCache.load(
+        template_name,
+        context: context,
+        parse_context: parse_context
+      )
+
+      context_variable_name = @alias_name || template_name.split('/').last
 
       variable = if @variable_name_expr
         context.evaluate(@variable_name_expr)
@@ -57,10 +67,10 @@ module Liquid
       end
 
       old_template_name = context.template_name
-      old_partial = context.partial
+      old_partial       = context.partial
       begin
         context.template_name = template_name
-        context.partial = true
+        context.partial       = true
         context.stack do
           @attributes.each do |key, value|
             context[key] = context.evaluate(value)
@@ -78,42 +88,15 @@ module Liquid
         end
       ensure
         context.template_name = old_template_name
-        context.partial = old_partial
+        context.partial       = old_partial
       end
 
       output
     end
 
-    private
-
     alias_method :parse_context, :options
     private :parse_context
 
-    def load_cached_partial(template_name, context)
-      cached_partials = context.registers[:cached_partials] || {}
-
-      if (cached = cached_partials[template_name])
-        return cached
-      end
-
-      source = read_template_from_file_system(context)
-      begin
-        parse_context.partial = true
-        partial = Liquid::Template.parse(source, parse_context)
-      ensure
-        parse_context.partial = false
-      end
-      cached_partials[template_name] = partial
-      context.registers[:cached_partials] = cached_partials
-      partial
-    end
-
-    def read_template_from_file_system(context)
-      file_system = context.registers[:file_system] || Liquid::Template.file_system
-
-      file_system.read_template_file(context.evaluate(@template_name_expr))
-    end
-
     class ParseTreeVisitor < Liquid::ParseTreeVisitor
       def children
         [

lib/liquid/tags/increment.rb

@@ -25,6 +25,7 @@ module Liquid
     def render_to_output_buffer(context, output)
       value = context.environments.first[@variable] ||= 0
       context.environments.first[@variable] = value + 1
+
       output << value.to_s
       output
     end

lib/liquid/tags/raw.rb

@@ -2,8 +2,8 @@
 
 module Liquid
   class Raw < Block
-    SYNTAX = /\A\s*\z/.freeze
-    FULL_TOKEN_POSSIBLY_INVALID = /\A(.*)#{TAG_START}\s*(\w+)\s*(.*)?#{TAG_END}\z/om.freeze
+    Syntax = /\A\s*\z/
+    FullTokenPossiblyInvalid = /\A(.*)#{TagStart}\s*(\w+)\s*(.*)?#{TagEnd}\z/om
 
     def initialize(tag_name, markup, parse_context)
       super
@@ -14,14 +14,14 @@ module Liquid
     def parse(tokens)
       @body = +''
       while (token = tokens.shift)
-        if token =~ FULL_TOKEN_POSSIBLY_INVALID
-          @body << Regexp.last_match(1) if Regexp.last_match(1) != ''
-          return if block_delimiter == Regexp.last_match(2)
+        if token =~ FullTokenPossiblyInvalid && block_delimiter == Regexp.last_match(2)
+          @body << Regexp.last_match(1) if Regexp.last_match(1) != ""
+          return
         end
         @body << token unless token.empty?
       end
 
-      raise SyntaxError, parse_context.locale.t('errors.syntax.tag_never_closed', block_name: block_name)
+      raise_tag_never_closed(block_name)
     end
 
     def render_to_output_buffer(_context, output)
@@ -40,7 +40,9 @@ module Liquid
     protected
 
     def ensure_valid_markup(tag_name, markup, parse_context)
-      raise SyntaxError, parse_context.locale.t('errors.syntax.tag_unexpected_args', tag: tag_name) unless markup =~ SYNTAX
+      unless Syntax.match?(markup)
+        raise SyntaxError, parse_context.locale.t("errors.syntax.tag_unexpected_args", tag: tag_name)
+      end
     end
   end
 

lib/liquid/tags/render.rb

@@ -0,0 +1,84 @@
+# frozen_string_literal: true
+
+module Liquid
+  class Render < Tag
+    FOR = 'for'
+    SYNTAX = /(#{QuotedString}+)(\s+(with|#{FOR})\s+(#{QuotedFragment}+))?(\s+(?:as)\s+(#{VariableSegment}+))?/o
+
+    disable_tags "include"
+
+    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)
+      with_or_for = Regexp.last_match(3)
+      variable_name = Regexp.last_match(4)
+
+      @alias_name = Regexp.last_match(6)
+      @variable_name_expr = variable_name ? parse_expression(variable_name) : nil
+      @template_name_expr = parse_expression(template_name)
+      @for = (with_or_for == FOR)
+
+      @attributes = {}
+      markup.scan(TagAttributes) do |key, value|
+        @attributes[key] = parse_expression(value)
+      end
+    end
+
+    def render_to_output_buffer(context, output)
+      render_tag(context, output)
+    end
+
+    def render_tag(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
+      )
+
+      context_variable_name = @alias_name || template_name.split('/').last
+
+      render_partial_func = ->(var, forloop) {
+        inner_context               = context.new_isolated_subcontext
+        inner_context.template_name = template_name
+        inner_context.partial       = true
+        inner_context['forloop']    = forloop if forloop
+
+        @attributes.each do |key, value|
+          inner_context[key] = context.evaluate(value)
+        end
+        inner_context[context_variable_name] = var unless var.nil?
+        partial.render_to_output_buffer(inner_context, output)
+        forloop&.send(:increment!)
+      }
+
+      variable = @variable_name_expr ? context.evaluate(@variable_name_expr) : nil
+      if @for && variable.respond_to?(:each) && variable.respond_to?(:count)
+        forloop = Liquid::ForloopDrop.new(template_name, variable.count, nil)
+        variable.each { |var| render_partial_func.call(var, forloop) }
+      else
+        render_partial_func.call(variable, nil)
+      end
+
+      output
+    end
+
+    class ParseTreeVisitor < Liquid::ParseTreeVisitor
+      def children
+        [
+          @node.template_name_expr,
+        ] + @node.attributes.values
+      end
+    end
+  end
+
+  Template.register_tag('render', Render)
+end

lib/liquid/tags/table_row.rb

@@ -2,21 +2,21 @@
 
 module Liquid
   class TableRow < Block
-    SYNTAX = /(\w+)\s+in\s+(#{QUOTED_FRAGMENT}+)/o.freeze
+    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))
-        @attributes = {}
-        markup.scan(TAG_ATTRIBUTES) do |key, value|
-          @attributes[key] = Expression.parse(value)
+      if markup =~ Syntax
+        @variable_name   = Regexp.last_match(1)
+        @collection_name = parse_expression(Regexp.last_match(2))
+        @attributes      = {}
+        markup.scan(TagAttributes) do |key, value|
+          @attributes[key] = parse_expression(value)
         end
       else
-        raise SyntaxError, options[:locale].t('errors.syntax.table_row')
+        raise SyntaxError, options[:locale].t("errors.syntax.table_row")
       end
     end
 
@@ -24,11 +24,10 @@ module Liquid
       (collection = context.evaluate(@collection_name)) || (return '')
 
       from = @attributes.key?('offset') ? context.evaluate(@attributes['offset']).to_i : 0
-      to = @attributes.key?('limit') ? from + context.evaluate(@attributes['limit']).to_i : nil
+      to   = @attributes.key?('limit')  ? from + context.evaluate(@attributes['limit']).to_i : nil
 
       collection = Utils.slice_collection(collection, from, to)
-
-      length = collection.length
+      length     = collection.length
 
       cols = context.evaluate(@attributes['cols']).to_i
 
@@ -44,7 +43,9 @@ module Liquid
           super
           output << '</td>'
 
-          output << "</tr>\n<tr class=\"row#{tablerowloop.row + 1}\">" if tablerowloop.col_last && !tablerowloop.last
+          if tablerowloop.col_last && !tablerowloop.last
+            output << "</tr>\n<tr class=\"row#{tablerowloop.row + 1}\">"
+          end
 
           tablerowloop.send(:increment!)
         end

lib/liquid/tags/unless.rb

@@ -9,14 +9,16 @@ module Liquid
   #
   class Unless < If
     def render_to_output_buffer(context, output)
-      context.stack do
-        # First condition is interpreted backwards ( if not )
-        first_block = @blocks.first
-        return first_block.attachment.render_to_output_buffer(context, output) unless first_block.evaluate(context)
+      # First condition is interpreted backwards ( if not )
+      first_block = @blocks.first
+      unless first_block.evaluate(context)
+        return first_block.attachment.render_to_output_buffer(context, output)
+      end
 
-        # After the first condition unless works just like if
-        @blocks[1..-1].each do |block|
-          return block.attachment.render_to_output_buffer(context, output) if block.evaluate(context)
+      # After the first condition unless works just like if
+      @blocks[1..-1].each do |block|
+        if block.evaluate(context)
+          return block.attachment.render_to_output_buffer(context, output)
         end
       end
 

lib/liquid/template.rb

@@ -18,17 +18,11 @@ module Liquid
     attr_accessor :root
     attr_reader :resource_limits, :warnings
 
-    @file_system = BlankFileSystem.new
-
-    class << self
-      attr_accessor :file_system
-    end
-
     class TagRegistry
       include Enumerable
 
       def initialize
-        @tags = {}
+        @tags  = {}
         @cache = {}
       end
 
@@ -67,68 +61,54 @@ module Liquid
       # :lax acts like liquid 2.5 and silently ignores malformed tags in most cases.
       # :warn is the default and will give deprecation warnings when invalid syntax is used.
       # :strict will enforce correct syntax.
-      attr_writer :error_mode
-
-      # Sets how strict the taint checker should be.
-      # :lax is the default, and ignores the taint flag completely
-      # :warn adds a warning, but does not interrupt the rendering
-      # :error raises an error when tainted output is used
-      attr_writer :taint_mode
+      attr_accessor :error_mode
+      Template.error_mode = :lax
 
       attr_accessor :default_exception_renderer
       Template.default_exception_renderer = lambda do |exception|
         exception
       end
 
+      attr_accessor :file_system
+      Template.file_system = BlankFileSystem.new
+
+      attr_accessor :tags
+      Template.tags = TagRegistry.new
+      private :tags=
+
       def register_tag(name, klass)
         tags[name.to_s] = klass
       end
 
-      def tags
-        @tags ||= TagRegistry.new
-      end
-
-      def error_mode
-        @error_mode ||= :lax
-      end
-
-      def taint_mode
-        @taint_mode ||= :lax
-      end
-
       # Pass a module with filter methods which should be available
       # to all liquid views. Good for registering the standard library
       def register_filter(mod)
-        Strainer.global_filter(mod)
+        StrainerFactory.add_global_filter(mod)
       end
 
-      def default_resource_limits
-        @default_resource_limits ||= {}
-      end
+      attr_accessor :default_resource_limits
+      Template.default_resource_limits = {}
+      private :default_resource_limits=
 
       # creates a new <tt>Template</tt> object from liquid source code
       # To enable profiling, pass in <tt>profile: true</tt> as an option.
       # See Liquid::Profiler for more information
       def parse(source, options = {})
-        template = Template.new
-        template.parse(source, options)
+        new.parse(source, options)
       end
     end
 
     def initialize
-      @rethrow_errors = false
-      @resource_limits = ResourceLimits.new(self.class.default_resource_limits)
+      @rethrow_errors  = false
+      @resource_limits = ResourceLimits.new(Template.default_resource_limits)
     end
 
     # Parse source code.
     # Returns self for easy chaining
     def parse(source, options = {})
-      @options = options
-      @profiling = options[:profile]
-      @line_numbers = options[:line_numbers] || @profiling
-      parse_context = options.is_a?(ParseContext) ? options : ParseContext.new(options)
-      @root = Document.parse(tokenize(source), parse_context)
-      @warnings = parse_context.warnings
+      parse_context = configure_options(options)
+      tokenizer     = parse_context.new_tokenizer(source, start_line_number: @line_numbers && 1)
+      @root         = Document.parse(tokenizer, parse_context)
       self
     end
 
@@ -169,28 +149,34 @@ module Liquid
       when Liquid::Context
         c = args.shift
 
-        c.exception_renderer = ->(_e) { raise } if @rethrow_errors
+        if @rethrow_errors
+          c.exception_renderer = Liquid::RAISE_EXCEPTION_LAMBDA
+        end
 
         c
       when Liquid::Drop
-        drop = args.shift
+        drop         = args.shift
         drop.context = Context.new([drop, assigns], instance_assigns, registers, @rethrow_errors, @resource_limits)
       when Hash
         Context.new([args.shift, assigns], instance_assigns, registers, @rethrow_errors, @resource_limits)
       when nil
         Context.new(assigns, instance_assigns, registers, @rethrow_errors, @resource_limits)
       else
-        raise ArgumentError, 'Expected Hash or Liquid::Context as parameter'
+        raise ArgumentError, "Expected Hash or Liquid::Context as parameter"
       end
 
       output = nil
 
+      context_register = context.registers.is_a?(StaticRegisters) ? context.registers.static : context.registers
+
       case args.last
       when Hash
         options = args.pop
-        output = options[:output] if options[:output]
+        output  = options[:output] if options[:output]
 
-        registers.merge!(options[:registers]) if options[:registers].is_a?(Hash)
+        options[:registers]&.each do |key, register|
+          context_register[key] = register
+        end
 
         apply_options_to_context(context, options)
       when Module, Array
@@ -200,12 +186,13 @@ module Liquid
       # Retrying a render resets resource usage
       context.resource_limits.reset
 
+      if @profiling && context.profiler.nil?
+        @profiler = context.profiler = Liquid::Profiler.new
+      end
+
       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 || +'')
-        end
+        @root.render_to_output_buffer(context, output || +'')
       rescue Liquid::MemoryError => e
         context.handle_error(e)
       ensure
@@ -224,33 +211,25 @@ module Liquid
 
     private
 
-    def tokenize(source)
-      Tokenizer.new(source, @line_numbers)
-    end
-
-    def with_profiling(context)
-      if @profiling && !context.partial
+    def configure_options(options)
+      if (profiling = options[:profile])
         raise "Profiler not loaded, require 'liquid/profiler' first" unless defined?(Liquid::Profiler)
-
-        @profiler = Profiler.new
-        @profiler.start
-
-        begin
-          yield
-        ensure
-          @profiler.stop
-        end
-      else
-        yield
       end
+
+      @options      = options
+      @profiling    = profiling
+      @line_numbers = options[:line_numbers] || @profiling
+      parse_context = options.is_a?(ParseContext) ? options : ParseContext.new(options)
+      @warnings     = parse_context.warnings
+      parse_context
     end
 
     def apply_options_to_context(context, options)
       context.add_filters(options[:filters]) if options[:filters]
-      context.global_filter = options[:global_filter] if options[:global_filter]
+      context.global_filter      = options[:global_filter] if options[:global_filter]
       context.exception_renderer = options[:exception_renderer] if options[:exception_renderer]
-      context.strict_variables = options[:strict_variables] if options[:strict_variables]
-      context.strict_filters = options[:strict_filters] if options[:strict_filters]
+      context.strict_variables   = options[:strict_variables] if options[:strict_variables]
+      context.strict_filters     = options[:strict_filters] if options[:strict_filters]
     end
   end
 end

lib/liquid/template_factory.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+module Liquid
+  class TemplateFactory
+    def for(_template_name)
+      Liquid::Template.new
+    end
+  end
+end

lib/liquid/tokenizer.rb

@@ -2,27 +2,33 @@
 
 module Liquid
   class Tokenizer
-    attr_reader :line_number
+    attr_reader :line_number, :for_liquid_tag
 
-    def initialize(source, line_numbers = false)
-      @source = source
-      @line_number = line_numbers ? 1 : nil
-      @tokens = tokenize
+    def initialize(source, line_numbers = false, line_number: nil, for_liquid_tag: false)
+      @source         = source
+      @line_number    = line_number || (line_numbers ? 1 : nil)
+      @for_liquid_tag = for_liquid_tag
+      @tokens         = tokenize
     end
 
     def shift
-      token = @tokens.shift
-      @line_number += token.count("\n") if @line_number && token
+      (token = @tokens.shift) || return
+
+      if @line_number
+        @line_number += @for_liquid_tag ? 1 : token.count("\n")
+      end
+
       token
     end
 
     private
 
     def tokenize
-      @source = @source.source if @source.respond_to?(:source)
       return [] if @source.to_s.empty?
 
-      tokens = @source.split(TEMPLATE_PARSER)
+      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?

lib/liquid/usage.rb

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

lib/liquid/utils.rb

@@ -12,7 +12,7 @@ module Liquid
 
     def self.slice_collection_using_each(collection, from, to)
       segments = []
-      index = 0
+      index    = 0
 
       # Maintains Ruby 1.8.7 String#each behaviour on 1.9
       if collection.is_a?(String)
@@ -21,9 +21,13 @@ module Liquid
       return [] unless collection.respond_to?(:each)
 
       collection.each do |item|
-        break if to && to <= index
+        if to && to <= index
+          break
+        end
 
-        segments << item if from <= index
+        if from <= index
+          segments << item
+        end
 
         index += 1
       end
@@ -33,12 +37,11 @@ module Liquid
 
     def self.to_integer(num)
       return num if num.is_a?(Integer)
-
       num = num.to_s
       begin
         Integer(num)
       rescue ::ArgumentError
-        raise Liquid::ArgumentError, 'invalid integer'
+        raise Liquid::ArgumentError, "invalid integer"
       end
     end
 
@@ -49,7 +52,7 @@ module Liquid
       when Numeric
         obj
       when String
-        obj.strip =~ /\A-?\d+\.\d+\z/ ? BigDecimal(obj) : obj.to_i
+        /\A-?\d+\.\d+\z/.match?(obj.strip) ? BigDecimal(obj) : obj.to_i
       else
         if obj.respond_to?(:to_number)
           obj.to_number
@@ -64,7 +67,6 @@ module Liquid
 
       if obj.is_a?(String)
         return nil if obj.empty?
-
         obj = obj.downcase
       end
 

lib/liquid/variable.rb

@@ -12,11 +12,11 @@ module Liquid
   #   {{ user | link }}
   #
   class Variable
-    FILTER_MARKUP_REGEX = /#{FILTER_SEPARATOR}\s*(.*)/om.freeze
-    FILTER_PARSER = /(?:\s+|#{QUOTED_FRAGMENT}|#{ARGUMENT_SEPARATOR})+/o.freeze
-    FILTER_ARGS_REGEX = /(?:#{FILTER_ARGUMENT_SEPARATOR}|#{ARGUMENT_SEPARATOR})\s*((?:\w+\s*\:\s*)?#{QUOTED_FRAGMENT})/o.freeze
-    JUST_TAG_ATTRIBUTES = /\A#{TAG_ATTRIBUTES}\z/o.freeze
-    MARKUP_WITH_QUOTED_FRAGMENT = /(#{QUOTED_FRAGMENT})(.*)/om.freeze
+    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
@@ -25,12 +25,12 @@ module Liquid
     include ParserSwitching
 
     def initialize(markup, parse_context)
-      @markup  = markup
-      @name    = nil
+      @markup        = markup
+      @name          = nil
       @parse_context = parse_context
-      @line_number = parse_context.line_number
+      @line_number   = parse_context.line_number
 
-      parse_with_selected_parser(markup)
+      strict_parse_with_error_mode_fallback(markup)
     end
 
     def raw
@@ -43,18 +43,17 @@ module Liquid
 
     def lax_parse(markup)
       @filters = []
-      return unless markup =~ MARKUP_WITH_QUOTED_FRAGMENT
+      return unless markup =~ MarkupWithQuotedFragment
 
-      name_markup = Regexp.last_match(1)
+      name_markup   = Regexp.last_match(1)
       filter_markup = Regexp.last_match(2)
-      @name = Expression.parse(name_markup)
-      if filter_markup =~ FILTER_MARKUP_REGEX
-        filters = Regexp.last_match(1).scan(FILTER_PARSER)
+      @name         = Expression.parse(name_markup)
+      if filter_markup =~ FilterMarkupRegex
+        filters = Regexp.last_match(1).scan(FilterParser)
         filters.each do |f|
           next unless f =~ /\w+/
-
           filtername = Regexp.last_match(0)
-          filterargs = f.scan(FILTER_ARGS_REGEX).flatten
+          filterargs = f.scan(FilterArgsRegex).flatten
           @filters << parse_filter_expressions(filtername, filterargs)
         end
       end
@@ -64,6 +63,8 @@ module Liquid
       @filters = []
       p = Parser.new(markup)
 
+      return if p.look(:end_of_string)
+
       @name = Expression.parse(p.expression)
       while p.consume?(:pipe)
         filtername = p.consume(:id)
@@ -82,14 +83,14 @@ module Liquid
     end
 
     def render(context)
-      obj = @filters.inject(context.evaluate(@name)) do |output, (filter_name, filter_args, filter_kwargs)|
+      obj = context.evaluate(@name)
+
+      @filters.each do |filter_name, filter_args, filter_kwargs|
         filter_args = evaluate_filter_expressions(context, filter_args, filter_kwargs)
-        context.invoke(filter_name, output, *filter_args)
+        obj = context.invoke(filter_name, obj, *filter_args)
       end
 
-      obj = context.apply_global_filter(obj)
-      taint_check(context, obj)
-      obj
+      context.apply_global_filter(obj)
     end
 
     def render_to_output_buffer(context, output)
@@ -105,14 +106,22 @@ module Liquid
       output
     end
 
+    def disabled?(_context)
+      false
+    end
+
+    def disabled_tags
+      []
+    end
+
     private
 
     def parse_filter_expressions(filter_name, unparsed_args)
-      filter_args = []
+      filter_args  = []
       keyword_args = nil
       unparsed_args.each do |a|
-        if (matches = a.match(JUST_TAG_ATTRIBUTES))
-          keyword_args ||= {}
+        if (matches = a.match(JustTagAttributes))
+          keyword_args           ||= {}
           keyword_args[matches[1]] = Expression.parse(matches[2])
         else
           filter_args << Expression.parse(a)
@@ -135,25 +144,6 @@ module Liquid
       parsed_args
     end
 
-    def taint_check(context, obj)
-      return unless obj.tainted?
-      return if Template.taint_mode == :lax
-
-      @markup =~ QUOTED_FRAGMENT
-      name = Regexp.last_match(0)
-
-      error = TaintedError.new("variable '#{name}' is tainted and was not escaped")
-      error.line_number = line_number
-      error.template_name = context.template_name
-
-      case Template.taint_mode
-      when :warn
-        context.warnings << error
-      when :error
-        raise error
-      end
-    end
-
     class ParseTreeVisitor < Liquid::ParseTreeVisitor
       def children
         [@node.name] + @node.filters.flatten

lib/liquid/variable_lookup.rb

@@ -2,8 +2,8 @@
 
 module Liquid
   class VariableLookup
-    SQUARE_BRACKETED = /\A\[(.*)\]\z/m.freeze
-    COMMAND_METHODS = %w[size first last].freeze
+    SQUARE_BRACKETED = /\A\[(.*)\]\z/m
+    COMMAND_METHODS  = ['size', 'first', 'last'].freeze
 
     attr_reader :name, :lookups
 
@@ -12,13 +12,15 @@ module Liquid
     end
 
     def initialize(markup)
-      lookups = markup.scan(VARIABLE_PARSER)
+      lookups = markup.scan(VariableParser)
 
       name = lookups.shift
-      name = Expression.parse(Regexp.last_match(1)) if name =~ SQUARE_BRACKETED
+      if name =~ SQUARE_BRACKETED
+        name = Expression.parse(Regexp.last_match(1))
+      end
       @name = name
 
-      @lookups = lookups
+      @lookups       = lookups
       @command_flags = 0
 
       @lookups.each_index do |i|
@@ -32,7 +34,7 @@ module Liquid
     end
 
     def evaluate(context)
-      name = context.evaluate(@name)
+      name   = context.evaluate(@name)
       object = context.find_variable(name)
 
       @lookups.each_index do |i|
@@ -41,11 +43,11 @@ module Liquid
         # If object is a hash- or array-like object we look for the
         # presence of the key and if its available we return it
         if object.respond_to?(:[]) &&
-           ((object.respond_to?(:key?) && object.key?(key)) ||
-            (object.respond_to?(:fetch) && key.is_a?(Integer)))
+            ((object.respond_to?(:key?) && object.key?(key)) ||
+             (object.respond_to?(:fetch) && key.is_a?(Integer)))
 
           # if its a proc we will replace the entry with the proc
-          res = context.lookup_and_evaluate(object, key)
+          res    = context.lookup_and_evaluate(object, key)
           object = res.to_liquid
 
           # Some special cases. If the part wasn't in square brackets and
@@ -59,7 +61,6 @@ module Liquid
           # raise an exception if `strict_variables` option is set to true
         else
           return nil unless context.strict_variables
-
           raise Liquid::UndefinedVariable, "undefined variable #{key}"
         end
 

lib/liquid/version.rb

@@ -1,5 +1,6 @@
+# encoding: utf-8
 # frozen_string_literal: true
 
 module Liquid
-  VERSION = '4.0.3'
+  VERSION = "5.0.1"
 end

liquid.gemspec

@@ -1,31 +1,34 @@
+# encoding: utf-8
 # frozen_string_literal: true
 
-lib = File.expand_path('lib', __dir__)
+lib = File.expand_path('../lib/', __FILE__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 
-require 'liquid/version'
+require "liquid/version"
 
 Gem::Specification.new do |s|
-  s.name        = 'liquid'
+  s.name        = "liquid"
   s.version     = Liquid::VERSION
   s.platform    = Gem::Platform::RUBY
-  s.summary     = 'A secure, non-evaling end user template engine with aesthetic markup.'
-  s.authors     = ['Tobias Lütke']
-  s.email       = ['tobi@leetsoft.com']
-  s.homepage    = 'http://www.liquidmarkup.org'
-  s.license     = 'MIT'
+  s.summary     = "A secure, non-evaling end user template engine with aesthetic markup."
+  s.authors     = ["Tobias Lütke"]
+  s.email       = ["tobi@leetsoft.com"]
+  s.homepage    = "http://www.liquidmarkup.org"
+  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_rubygems_version = '>= 1.3.7'
+  s.required_ruby_version     = ">= 2.5.0"
+  s.required_rubygems_version = ">= 1.3.7"
 
-  s.test_files  = Dir.glob('{test}/**/*')
-  s.files       = Dir.glob('{lib}/**/*') + %w[LICENSE README.md]
+  s.metadata['allowed_push_host'] = 'https://rubygems.org'
 
-  s.extra_rdoc_files = ['History.md', 'README.md']
+  s.test_files  = Dir.glob("{test}/**/*")
+  s.files       = Dir.glob("{lib}/**/*") + %w(LICENSE README.md)
 
-  s.require_path = 'lib'
+  s.extra_rdoc_files = ["History.md", "README.md"]
 
+  s.require_path = "lib"
+
+  s.add_development_dependency('rake', '~> 13.0')
   s.add_development_dependency('minitest')
-  s.add_development_dependency('rake', '~> 11.3')
 end

performance/benchmark.rb

@@ -7,14 +7,14 @@ Liquid::Template.error_mode = ARGV.first.to_sym if ARGV.first
 profiler = ThemeRunner.new
 
 Benchmark.ips do |x|
-  x.time = 10
+  x.time   = 10
   x.warmup = 5
 
   puts
   puts "Running benchmark for #{x.time} seconds (with #{x.warmup} seconds warmup)."
   puts
 
-  x.report('parse:') { profiler.compile }
-  x.report('render:') { profiler.render }
-  x.report('parse & render:') { profiler.run }
+  x.report("parse:") { profiler.compile }
+  x.report("render:") { profiler.render }
+  x.report("parse & render:") { profiler.run }
 end

performance/memory_profile.rb

@@ -2,25 +2,62 @@
 
 require 'benchmark/ips'
 require 'memory_profiler'
+require 'terminal-table'
 require_relative 'theme_runner'
 
-def profile(phase, &block)
-  puts
-  puts "#{phase}:"
-  puts
+class Profiler
+  LOG_LABEL   = "Profiling: ".rjust(14).freeze
+  REPORTS_DIR = File.expand_path('.memprof', __dir__).freeze
 
-  report = MemoryProfiler.report(&block)
+  def self.run
+    puts
+    yield new
+  end
 
-  report.pretty_print(
-    color_output: true,
-    scale_bytes: true,
-    detailed_report: true
-  )
+  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
 
-profiler = ThemeRunner.new
-
-profile('Parsing') { profiler.compile }
-profile('Rendering') { profiler.render }
+runner = ThemeRunner.new
+Profiler.run do |x|
+  x.profile('parse') { runner.compile }
+  x.profile('render') { runner.render }
+  x.tabulate
+end

performance/profile.rb

@@ -7,7 +7,7 @@ Liquid::Template.error_mode = ARGV.first.to_sym if ARGV.first
 profiler = ThemeRunner.new
 profiler.run
 
-%i[cpu object].each do |profile_type|
+[:cpu, :object].each do |profile_type|
   puts "Profiling in #{profile_type} mode..."
   results = StackProf.run(mode: profile_type) do
     200.times do
@@ -22,5 +22,5 @@ profiler.run
   end
 
   StackProf::Report.new(results).print_text(false, 20)
-  File.write(ENV['FILENAME'] + '.' + profile_type.to_s, Marshal.dump(results)) if ENV['FILENAME']
+  File.write(ENV['FILENAME'] + "." + profile_type.to_s, Marshal.dump(results)) if ENV['FILENAME']
 end

performance/shopify/comment_form.rb

@@ -1,14 +1,14 @@
 # frozen_string_literal: true
 
 class CommentForm < Liquid::Block
-  SYNTAX = /(#{Liquid::VARIABLE_SIGNATURE}+)/.freeze
+  Syntax = /(#{Liquid::VariableSignature}+)/
 
   def initialize(tag_name, markup, options)
     super
 
-    if markup =~ SYNTAX
+    if markup =~ Syntax
       @variable_name = Regexp.last_match(1)
-      @attributes = {}
+      @attributes    = {}
     else
       raise SyntaxError, "Syntax Error in 'comment_form' - Valid syntax: comment_form [article]"
     end

performance/shopify/database.rb

@@ -21,9 +21,7 @@ module Database
       db = db.each_with_object({}) do |(key, values), assigns|
         assigns[key] = values.each_with_object({}) do |v, h|
           h[v['handle']] = v
-          h
         end
-        assigns
       end
 
       # Some standard direct accessors so that the specialized templates

performance/shopify/json_filter.rb

@@ -4,6 +4,6 @@ require 'json'
 
 module JsonFilter
   def json(object)
-    JSON.dump(object.reject { |k, _v| k == 'collections' })
+    JSON.dump(object.reject { |k, _v| k == "collections" })
   end
 end

performance/shopify/money_filter.rb

@@ -3,14 +3,12 @@
 module MoneyFilter
   def money_with_currency(money)
     return '' if money.nil?
-
-    format('$ %.2f USD', money / 100.0)
+    format("$ %.2f USD", money / 100.0)
   end
 
   def money(money)
     return '' if money.nil?
-
-    format('$ %.2f', money / 100.0)
+    format("$ %.2f", money / 100.0)
   end
 
   private

performance/shopify/paginate.rb

@@ -1,21 +1,21 @@
 # frozen_string_literal: true
 
 class Paginate < Liquid::Block
-  SYNTAX = /(#{Liquid::QUOTED_FRAGMENT})\s*(by\s*(\d+))?/.freeze
+  Syntax = /(#{Liquid::QuotedFragment})\s*(by\s*(\d+))?/
 
   def initialize(tag_name, markup, options)
     super
 
-    if markup =~ SYNTAX
+    if markup =~ Syntax
       @collection_name = Regexp.last_match(1)
-      @page_size = if Regexp.last_match(2)
+      @page_size       = if Regexp.last_match(2)
         Regexp.last_match(3).to_i
       else
         20
       end
 
       @attributes = { 'window_size' => 3 }
-      markup.scan(Liquid::TAG_ATTRIBUTES) do |key, value|
+      markup.scan(Liquid::TagAttributes) do |key, value|
         @attributes[key] = value
       end
     else
@@ -45,7 +45,7 @@ class Paginate < Liquid::Block
 
       pagination['items']      = collection_size
       pagination['pages']      = page_count - 1
-      pagination['previous']   = link('&laquo; Previous', current_page - 1)  unless current_page <= 1
+      pagination['previous']   = link('&laquo; Previous', current_page - 1)  unless 1 >= current_page
       pagination['next']       = link('Next &raquo;', current_page + 1)      unless page_count <= current_page + 1
       pagination['parts']      = []
 
@@ -61,7 +61,6 @@ class Paginate < Liquid::Block
             pagination['parts'] << link(page, page)
           elsif page <= current_page - @attributes['window_size'] || page >= current_page + @attributes['window_size']
             next if hellip_break
-
             pagination['parts'] << no_link('&hellip;')
             hellip_break = true
             next
@@ -88,6 +87,6 @@ class Paginate < Liquid::Block
   end
 
   def current_url
-    '/collections/frontpage'
+    "/collections/frontpage"
   end
 end

performance/shopify/shop_filter.rb

@@ -17,21 +17,21 @@ module ShopFilter
     %(<script src="#{url}" type="text/javascript"></script>)
   end
 
-  def stylesheet_tag(url, media = 'all')
+  def stylesheet_tag(url, media = "all")
     %(<link href="#{url}" rel="stylesheet" type="text/css"  media="#{media}"  />)
   end
 
-  def link_to(link, url, title = '')
+  def link_to(link, url, title = "")
     %(<a href="#{url}" title="#{title}">#{link}</a>)
   end
 
-  def img_tag(url, alt = '')
+  def img_tag(url, alt = "")
     %(<img src="#{url}" alt="#{alt}" />)
   end
 
   def link_to_vendor(vendor)
     if vendor
-      link_to vendor, url_for_vendor(vendor), vendor
+      link_to(vendor, url_for_vendor(vendor), vendor)
     else
       'Unknown Vendor'
     end
@@ -39,7 +39,7 @@ module ShopFilter
 
   def link_to_type(type)
     if type
-      link_to type, url_for_type(type), type
+      link_to(type, url_for_type(type), type)
     else
       'Unknown Vendor'
     end
@@ -54,11 +54,13 @@ module ShopFilter
   end
 
   def product_img_url(url, style = 'small')
-    raise ArgumentError, 'filter "size" can only be called on product images' unless url =~ %r{\Aproducts/([\w\-\_]+)\.(\w{2,4})}
+    unless url =~ %r{\Aproducts/([\w\-\_]+)\.(\w{2,4})}
+      raise ArgumentError, 'filter "size" can only be called on product images'
+    end
 
     case style
     when 'original'
-      return '/files/shops/random_number/' + url
+      '/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)}"
     else

performance/shopify/weight_filter.rb

@@ -2,7 +2,7 @@
 
 module WeightFilter
   def weight(grams)
-    format('%.2f', grams / 1000)
+    format("%.2f", grams / 1000)
   end
 
   def weight_with_unit(grams)

performance/theme_runner.rb

@@ -58,9 +58,9 @@ class ThemeRunner
   # `render` is called to benchmark just the render portion of liquid
   def render
     @compiled_tests.each do |test|
-      tmpl = test[:tmpl]
+      tmpl    = test[:tmpl]
       assigns = test[:assigns]
-      layout = test[:layout]
+      layout  = test[:layout]
 
       if layout
         assigns['content_for_layout'] = tmpl.render!(assigns)
@@ -73,10 +73,14 @@ class ThemeRunner
 
   private
 
+  def render_layout(template, layout, assigns)
+    assigns['content_for_layout'] = template.render!(assigns)
+    layout&.render!(assigns)
+  end
+
   def compile_and_render(template, layout, assigns, page_template, template_file)
     compiled_test = compile_test(template, layout, assigns, page_template, template_file)
-    assigns['content_for_layout'] = compiled_test[:tmpl].render!(assigns)
-    compiled_test[:layout].render!(assigns) if layout
+    render_layout(compiled_test[:tmpl], compiled_test[:layout], compiled_test[:assigns])
   end
 
   def compile_all_tests
@@ -88,7 +92,7 @@ class ThemeRunner
   end
 
   def compile_test(template, layout, assigns, page_template, template_file)
-    tmpl = init_template(page_template, template_file)
+    tmpl            = init_template(page_template, template_file)
     parsed_template = tmpl.parse(template).dup
 
     if layout
@@ -113,9 +117,9 @@ class ThemeRunner
 
   # set up a new Liquid::Template object for use in `compile_and_render` and `compile_test`
   def init_template(page_template, template_file)
-    tmpl = Liquid::Template.new
-    tmpl.assigns['page_title'] = 'Page title'
-    tmpl.assigns['template'] = page_template
+    tmpl                         = Liquid::Template.new
+    tmpl.assigns['page_title']   = 'Page title'
+    tmpl.assigns['template']     = page_template
     tmpl.registers[:file_system] = ThemeRunner::FileSystem.new(File.dirname(template_file))
     tmpl
   end

test/integration/assign_test.rb

@@ -10,31 +10,31 @@ class AssignTest < Minitest::Test
     {% assign this-thing = 'Print this-thing' %}
     {{ this-thing }}
     END_TEMPLATE
-    template = Template.parse(template_source)
-    rendered = template.render!
-    assert_equal 'Print this-thing', rendered.strip
+    template        = Template.parse(template_source)
+    rendered        = template.render!
+    assert_equal("Print this-thing", rendered.strip)
   end
 
   def test_assigned_variable
     assert_template_result('.foo.',
-                           '{% assign foo = values %}.{{ foo[0] }}.',
-                           'values' => %w[foo bar baz])
+      '{% assign foo = values %}.{{ foo[0] }}.',
+      'values' => %w(foo bar baz))
 
     assert_template_result('.bar.',
-                           '{% assign foo = values %}.{{ foo[1] }}.',
-                           'values' => %w[foo bar baz])
+      '{% assign foo = values %}.{{ foo[1] }}.',
+      'values' => %w(foo bar baz))
   end
 
   def test_assign_with_filter
     assert_template_result('.bar.',
-                           '{% assign foo = values | split: "," %}.{{ foo[1] }}.',
-                           'values' => 'foo,bar,baz')
+      '{% assign foo = values | split: "," %}.{{ foo[1] }}.',
+      'values' => "foo,bar,baz")
   end
 
   def test_assign_syntax_error
     assert_match_syntax_error(/assign/,
-                              '{% assign foo not values %}.',
-                              'values' => 'foo,bar,baz')
+      '{% assign foo not values %}.',
+      'values' => "foo,bar,baz")
   end
 
   def test_assign_uses_error_mode
@@ -44,7 +44,74 @@ class AssignTest < Minitest::Test
       end
     end
     with_error_mode(:lax) do
-      assert Template.parse("{% assign foo = ('X' | downcase) %}")
+      assert(Template.parse("{% assign foo = ('X' | downcase) %}"))
     end
   end
-end # AssignTest
+
+  def test_expression_with_whitespace_in_square_brackets
+    source = "{% assign r = a[ 'b' ] %}{{ r }}"
+    assert_template_result('result', source, 'a' => { 'b' => 'result' })
+  end
+
+  def test_assign_score_exceeding_resource_limit
+    t = Template.parse("{% assign foo = 42 %}{% assign bar = 23 %}")
+    t.resource_limits.assign_score_limit = 1
+    assert_equal("Liquid error: Memory limits exceeded", t.render)
+    assert(t.resource_limits.reached?)
+
+    t.resource_limits.assign_score_limit = 2
+    assert_equal("", t.render!)
+    refute_nil(t.resource_limits.assign_score)
+  end
+
+  def test_assign_score_exceeding_limit_from_composite_object
+    t = Template.parse("{% assign foo = 'aaaa' | reverse %}")
+
+    t.resource_limits.assign_score_limit = 3
+    assert_equal("Liquid error: Memory limits exceeded", t.render)
+    assert(t.resource_limits.reached?)
+
+    t.resource_limits.assign_score_limit = 5
+    assert_equal("", t.render!)
+  end
+
+  def test_assign_score_of_int
+    assert_equal(1, assign_score_of(123))
+  end
+
+  def test_assign_score_of_string_counts_bytes
+    assert_equal(3, assign_score_of('123'))
+    assert_equal(5, assign_score_of('12345'))
+    assert_equal(9, assign_score_of('すごい'))
+  end
+
+  def test_assign_score_of_array
+    assert_equal(1, assign_score_of([]))
+    assert_equal(2, assign_score_of([123]))
+    assert_equal(6, assign_score_of([123, 'abcd']))
+  end
+
+  def test_assign_score_of_hash
+    assert_equal(1, assign_score_of({}))
+    assert_equal(5, assign_score_of('int' => 123))
+    assert_equal(12, assign_score_of('int' => 123, 'str' => 'abcd'))
+  end
+
+  private
+
+  class ObjectWrapperDrop < Liquid::Drop
+    def initialize(obj)
+      @obj = obj
+    end
+
+    def value
+      @obj
+    end
+  end
+
+  def assign_score_of(obj)
+    context = Liquid::Context.new('drop' => ObjectWrapperDrop.new(obj))
+    Liquid::Template.parse('{% assign obj = drop.value %}').render!(context)
+    context.resource_limits.assign_score
+  end
+end

test/integration/blank_test.rb

@@ -33,77 +33,77 @@ class BlankTest < Minitest::Test
 
   def test_new_tags_are_not_blank_by_default
     with_custom_tag('foobar', FoobarTag) do
-      assert_template_result(' ' * N, wrap_in_for('{% foobar %}'))
+      assert_template_result(" " * N, wrap_in_for("{% foobar %}"))
     end
   end
 
   def test_loops_are_blank
-    assert_template_result('', wrap_in_for(' '))
+    assert_template_result("", wrap_in_for(" "))
   end
 
   def test_if_else_are_blank
-    assert_template_result('', '{% if true %} {% elsif false %} {% else %} {% endif %}')
+    assert_template_result("", "{% if true %} {% elsif false %} {% else %} {% endif %}")
   end
 
   def test_unless_is_blank
-    assert_template_result('', wrap('{% unless true %} {% endunless %}'))
+    assert_template_result("", wrap("{% unless true %} {% endunless %}"))
   end
 
   def test_mark_as_blank_only_during_parsing
-    assert_template_result(' ' * (N + 1), wrap(' {% if false %} this never happens, but still, this block is not blank {% endif %}'))
+    assert_template_result(" " * (N + 1), wrap(" {% if false %} this never happens, but still, this block is not blank {% endif %}"))
   end
 
   def test_comments_are_blank
-    assert_template_result('', wrap(' {% comment %} whatever {% endcomment %} '))
+    assert_template_result("", wrap(" {% comment %} whatever {% endcomment %} "))
   end
 
   def test_captures_are_blank
-    assert_template_result('', wrap(' {% capture foo %} whatever {% endcapture %} '))
+    assert_template_result("", wrap(" {% capture foo %} whatever {% endcapture %} "))
   end
 
   def test_nested_blocks_are_blank_but_only_if_all_children_are
-    assert_template_result('', wrap(wrap(' ')))
+    assert_template_result("", wrap(wrap(" ")))
     assert_template_result("\n       but this is not " * (N + 1),
-                           wrap('{% if true %} {% comment %} this is blank {% endcomment %} {% endif %}
+      wrap('{% if true %} {% comment %} this is blank {% endcomment %} {% endif %}
       {% if true %} but this is not {% endif %}'))
   end
 
   def test_assigns_are_blank
-    assert_template_result('', wrap(' {% assign foo = "bar" %} '))
+    assert_template_result("", wrap(' {% assign foo = "bar" %} '))
   end
 
   def test_whitespace_is_blank
-    assert_template_result('', wrap(' '))
-    assert_template_result('', wrap("\t"))
+    assert_template_result("", wrap(" "))
+    assert_template_result("", wrap("\t"))
   end
 
   def test_whitespace_is_not_blank_if_other_stuff_is_present
-    body = '     x '
+    body = "     x "
     assert_template_result(body * (N + 1), wrap(body))
   end
 
   def test_increment_is_not_blank
-    assert_template_result(' 0' * 2 * (N + 1), wrap('{% assign foo = 0 %} {% increment foo %} {% decrement foo %}'))
+    assert_template_result(" 0" * 2 * (N + 1), wrap("{% assign foo = 0 %} {% increment foo %} {% decrement foo %}"))
   end
 
   def test_cycle_is_not_blank
-    assert_template_result('  ' * ((N + 1) / 2) + ' ', wrap("{% cycle ' ', ' ' %}"))
+    assert_template_result("  " * ((N + 1) / 2) + " ", wrap("{% cycle ' ', ' ' %}"))
   end
 
   def test_raw_is_not_blank
-    assert_template_result('  ' * (N + 1), wrap(' {% raw %} {% endraw %}'))
+    assert_template_result("  " * (N + 1), wrap(" {% raw %} {% endraw %}"))
   end
 
   def test_include_is_blank
     Liquid::Template.file_system = BlankTestFileSystem.new
-    assert_template_result 'foobar' * (N + 1), wrap("{% include 'foobar' %}")
-    assert_template_result ' foobar ' * (N + 1), wrap("{% include ' foobar ' %}")
-    assert_template_result '   ' * (N + 1), wrap(" {% include ' ' %} ")
+    assert_template_result("foobar" * (N + 1), wrap("{% include 'foobar' %}"))
+    assert_template_result(" foobar " * (N + 1), wrap("{% include ' foobar ' %}"))
+    assert_template_result("   " * (N + 1), wrap(" {% include ' ' %} "))
   end
 
   def test_case_is_blank
-    assert_template_result('', wrap(" {% assign foo = 'bar' %} {% case foo %} {% when 'bar' %} {% when 'whatever' %} {% else %} {% endcase %} "))
-    assert_template_result('', wrap(" {% assign foo = 'else' %} {% case foo %} {% when 'bar' %} {% when 'whatever' %} {% else %} {% endcase %} "))
-    assert_template_result('   x  ' * (N + 1), wrap(" {% assign foo = 'else' %} {% case foo %} {% when 'bar' %} {% when 'whatever' %} {% else %} x {% endcase %} "))
+    assert_template_result("", wrap(" {% assign foo = 'bar' %} {% case foo %} {% when 'bar' %} {% when 'whatever' %} {% else %} {% endcase %} "))
+    assert_template_result("", wrap(" {% assign foo = 'else' %} {% case foo %} {% when 'bar' %} {% when 'whatever' %} {% else %} {% endcase %} "))
+    assert_template_result("   x  " * (N + 1), wrap(" {% assign foo = 'else' %} {% case foo %} {% when 'bar' %} {% when 'whatever' %} {% else %} x {% endcase %} "))
   end
 end

test/integration/block_test.rb

@@ -7,8 +7,52 @@ class BlockTest < Minitest::Test
 
   def test_unexpected_end_tag
     exc = assert_raises(SyntaxError) do
-      Template.parse('{% if true %}{% endunless %}')
+      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
+
+  def test_with_custom_tag
+    with_custom_tag('testtag', Block) do
+      assert(Liquid::Template.parse("{% testtag %} {% endtesttag %}"))
+    end
+  end
+
+  def test_custom_block_tags_have_a_default_render_to_output_buffer_method_for_backwards_compatibility
+    klass1 = Class.new(Block) do
+      def render(*)
+        'hello'
+      end
+    end
+
+    with_custom_tag('blabla', klass1) do
+      template = Liquid::Template.parse("{% blabla %} bla {% endblabla %}")
+
+      assert_equal('hello', template.render)
+
+      buf    = +''
+      output = template.render({}, output: buf)
+      assert_equal('hello', output)
+      assert_equal('hello', buf)
+      assert_equal(buf.object_id, output.object_id)
+    end
+
+    klass2 = Class.new(klass1) do
+      def render(*)
+        'foo' + super + 'bar'
+      end
+    end
+
+    with_custom_tag('blabla', klass2) do
+      template = Liquid::Template.parse("{% blabla %} foo {% endblabla %}")
+
+      assert_equal('foohellobar', template.render)
+
+      buf    = +''
+      output = template.render({}, output: buf)
+      assert_equal('foohellobar', output)
+      assert_equal('foohellobar', buf)
+      assert_equal(buf.object_id, output.object_id)
     end
-    assert_equal exc.message, "Liquid syntax error: 'endunless' is not a valid delimiter for if tags. use endif"
   end
 end

test/integration/capture_test.rb

@@ -6,7 +6,7 @@ class CaptureTest < Minitest::Test
   include Liquid
 
   def test_captures_block_content_in_variable
-    assert_template_result('test string', "{% capture 'var' %}test string{% endcapture %}{{var}}", {})
+    assert_template_result("test string", "{% capture 'var' %}test string{% endcapture %}{{var}}", {})
   end
 
   def test_capture_with_hyphen_in_variable_name
@@ -14,9 +14,9 @@ class CaptureTest < Minitest::Test
     {% capture this-thing %}Print this-thing{% endcapture %}
     {{ this-thing }}
     END_TEMPLATE
-    template = Template.parse(template_source)
-    rendered = template.render!
-    assert_equal 'Print this-thing', rendered.strip
+    template        = Template.parse(template_source)
+    rendered        = template.render!
+    assert_equal("Print this-thing", rendered.strip)
   end
 
   def test_capture_to_variable_from_outer_scope_if_existing
@@ -30,9 +30,9 @@ class CaptureTest < Minitest::Test
     {% endif %}
     {{var}}
     END_TEMPLATE
-    template = Template.parse(template_source)
-    rendered = template.render!
-    assert_equal 'test-string', rendered.gsub(/\s/, '')
+    template        = Template.parse(template_source)
+    rendered        = template.render!
+    assert_equal("test-string", rendered.gsub(/\s/, ''))
   end
 
   def test_assigning_from_capture
@@ -45,8 +45,14 @@ class CaptureTest < Minitest::Test
     {% endfor %}
     {{ first }}-{{ second }}
     END_TEMPLATE
-    template = Template.parse(template_source)
-    rendered = template.render!
-    assert_equal '3-3', rendered.gsub(/\s/, '')
+    template        = Template.parse(template_source)
+    rendered        = template.render!
+    assert_equal("3-3", rendered.gsub(/\s/, ''))
   end
-end # CaptureTest
+
+  def test_increment_assign_score_by_bytes_not_characters
+    t = Template.parse("{% capture foo %}すごい{% endcapture %}")
+    t.render!
+    assert_equal(9, t.resource_limits.assign_score)
+  end
+end

test/integration/context_test.rb

@@ -2,9 +2,597 @@
 
 require 'test_helper'
 
+class HundredCentes
+  def to_liquid
+    100
+  end
+end
+
+class CentsDrop < Liquid::Drop
+  def amount
+    HundredCentes.new
+  end
+
+  def non_zero?
+    true
+  end
+end
+
+class ContextSensitiveDrop < Liquid::Drop
+  def test
+    @context['test']
+  end
+end
+
+class Category < Liquid::Drop
+  attr_accessor :name
+
+  def initialize(name)
+    @name = name
+  end
+
+  def to_liquid
+    CategoryDrop.new(self)
+  end
+end
+
+class CategoryDrop
+  attr_accessor :category, :context
+  def initialize(category)
+    @category = category
+  end
+end
+
+class CounterDrop < Liquid::Drop
+  def count
+    @count ||= 0
+    @count  += 1
+  end
+end
+
+class ArrayLike
+  def fetch(index)
+  end
+
+  def [](index)
+    @counts        ||= []
+    @counts[index] ||= 0
+    @counts[index]  += 1
+  end
+
+  def to_liquid
+    self
+  end
+end
+
 class ContextTest < Minitest::Test
   include Liquid
 
+  def setup
+    @context = Liquid::Context.new
+  end
+
+  def test_variables
+    @context['string'] = 'string'
+    assert_equal('string', @context['string'])
+
+    @context['num'] = 5
+    assert_equal(5, @context['num'])
+
+    @context['time'] = Time.parse('2006-06-06 12:00:00')
+    assert_equal(Time.parse('2006-06-06 12:00:00'), @context['time'])
+
+    @context['date'] = Date.today
+    assert_equal(Date.today, @context['date'])
+
+    now = Time.now
+    @context['datetime'] = now
+    assert_equal(now, @context['datetime'])
+
+    @context['bool'] = true
+    assert_equal(true, @context['bool'])
+
+    @context['bool'] = false
+    assert_equal(false, @context['bool'])
+
+    @context['nil'] = nil
+    assert_nil(@context['nil'])
+    assert_nil(@context['nil'])
+  end
+
+  def test_variables_not_existing
+    assert_nil(@context['does_not_exist'])
+  end
+
+  def test_scoping
+    @context.push
+    @context.pop
+
+    assert_raises(Liquid::ContextError) do
+      @context.pop
+    end
+
+    assert_raises(Liquid::ContextError) do
+      @context.push
+      @context.pop
+      @context.pop
+    end
+  end
+
+  def test_length_query
+    @context['numbers'] = [1, 2, 3, 4]
+
+    assert_equal(4, @context['numbers.size'])
+
+    @context['numbers'] = { 1 => 1, 2 => 2, 3 => 3, 4 => 4 }
+
+    assert_equal(4, @context['numbers.size'])
+
+    @context['numbers'] = { 1 => 1, 2 => 2, 3 => 3, 4 => 4, 'size' => 1000 }
+
+    assert_equal(1000, @context['numbers.size'])
+  end
+
+  def test_hyphenated_variable
+    @context['oh-my'] = 'godz'
+    assert_equal('godz', @context['oh-my'])
+  end
+
+  def test_add_filter
+    filter = Module.new do
+      def hi(output)
+        output + ' hi!'
+      end
+    end
+
+    context = Context.new
+    context.add_filters(filter)
+    assert_equal('hi? hi!', context.invoke(:hi, 'hi?'))
+
+    context = Context.new
+    assert_equal('hi?', context.invoke(:hi, 'hi?'))
+
+    context.add_filters(filter)
+    assert_equal('hi? hi!', context.invoke(:hi, 'hi?'))
+  end
+
+  def test_only_intended_filters_make_it_there
+    filter = Module.new do
+      def hi(output)
+        output + ' hi!'
+      end
+    end
+
+    context = Context.new
+    assert_equal("Wookie", context.invoke("hi", "Wookie"))
+
+    context.add_filters(filter)
+    assert_equal("Wookie hi!", context.invoke("hi", "Wookie"))
+  end
+
+  def test_add_item_in_outer_scope
+    @context['test'] = 'test'
+    @context.push
+    assert_equal('test', @context['test'])
+    @context.pop
+    assert_equal('test', @context['test'])
+  end
+
+  def test_add_item_in_inner_scope
+    @context.push
+    @context['test'] = 'test'
+    assert_equal('test', @context['test'])
+    @context.pop
+    assert_nil(@context['test'])
+  end
+
+  def test_hierachical_data
+    @context['hash'] = { "name" => 'tobi' }
+    assert_equal('tobi', @context['hash.name'])
+    assert_equal('tobi', @context['hash["name"]'])
+  end
+
+  def test_keywords
+    assert_equal(true, @context['true'])
+    assert_equal(false, @context['false'])
+  end
+
+  def test_digits
+    assert_equal(100, @context['100'])
+    assert_equal(100.00, @context['100.00'])
+  end
+
+  def test_strings
+    assert_equal("hello!", @context['"hello!"'])
+    assert_equal("hello!", @context["'hello!'"])
+  end
+
+  def test_merge
+    @context.merge("test" => "test")
+    assert_equal('test', @context['test'])
+    @context.merge("test" => "newvalue", "foo" => "bar")
+    assert_equal('newvalue', @context['test'])
+    assert_equal('bar', @context['foo'])
+  end
+
+  def test_array_notation
+    @context['test'] = [1, 2, 3, 4, 5]
+
+    assert_equal(1, @context['test[0]'])
+    assert_equal(2, @context['test[1]'])
+    assert_equal(3, @context['test[2]'])
+    assert_equal(4, @context['test[3]'])
+    assert_equal(5, @context['test[4]'])
+  end
+
+  def test_recoursive_array_notation
+    @context['test'] = { 'test' => [1, 2, 3, 4, 5] }
+
+    assert_equal(1, @context['test.test[0]'])
+
+    @context['test'] = [{ 'test' => 'worked' }]
+
+    assert_equal('worked', @context['test[0].test'])
+  end
+
+  def test_hash_to_array_transition
+    @context['colors'] = {
+      'Blue' => ['003366', '336699', '6699CC', '99CCFF'],
+      'Green' => ['003300', '336633', '669966', '99CC99'],
+      'Yellow' => ['CC9900', 'FFCC00', 'FFFF99', 'FFFFCC'],
+      'Red' => ['660000', '993333', 'CC6666', 'FF9999'],
+    }
+
+    assert_equal('003366', @context['colors.Blue[0]'])
+    assert_equal('FF9999', @context['colors.Red[3]'])
+  end
+
+  def test_try_first
+    @context['test'] = [1, 2, 3, 4, 5]
+
+    assert_equal(1, @context['test.first'])
+    assert_equal(5, @context['test.last'])
+
+    @context['test'] = { 'test' => [1, 2, 3, 4, 5] }
+
+    assert_equal(1, @context['test.test.first'])
+    assert_equal(5, @context['test.test.last'])
+
+    @context['test'] = [1]
+    assert_equal(1, @context['test.first'])
+    assert_equal(1, @context['test.last'])
+  end
+
+  def test_access_hashes_with_hash_notation
+    @context['products'] = { 'count' => 5, 'tags' => ['deepsnow', 'freestyle'] }
+    @context['product']  = { 'variants' => [{ 'title' => 'draft151cm' }, { 'title' => 'element151cm' }] }
+
+    assert_equal(5, @context['products["count"]'])
+    assert_equal('deepsnow', @context['products["tags"][0]'])
+    assert_equal('deepsnow', @context['products["tags"].first'])
+    assert_equal('draft151cm', @context['product["variants"][0]["title"]'])
+    assert_equal('element151cm', @context['product["variants"][1]["title"]'])
+    assert_equal('draft151cm', @context['product["variants"][0]["title"]'])
+    assert_equal('element151cm', @context['product["variants"].last["title"]'])
+  end
+
+  def test_access_variable_with_hash_notation
+    @context['foo'] = 'baz'
+    @context['bar'] = 'foo'
+
+    assert_equal('baz', @context['["foo"]'])
+    assert_equal('baz', @context['[bar]'])
+  end
+
+  def test_access_hashes_with_hash_access_variables
+    @context['var']      = 'tags'
+    @context['nested']   = { 'var' => 'tags' }
+    @context['products'] = { 'count' => 5, 'tags' => ['deepsnow', 'freestyle'] }
+
+    assert_equal('deepsnow', @context['products[var].first'])
+    assert_equal('freestyle', @context['products[nested.var].last'])
+  end
+
+  def test_hash_notation_only_for_hash_access
+    @context['array'] = [1, 2, 3, 4, 5]
+    @context['hash']  = { 'first' => 'Hello' }
+
+    assert_equal(1, @context['array.first'])
+    assert_nil(@context['array["first"]'])
+    assert_equal('Hello', @context['hash["first"]'])
+  end
+
+  def test_first_can_appear_in_middle_of_callchain
+    @context['product'] = { 'variants' => [{ 'title' => 'draft151cm' }, { 'title' => 'element151cm' }] }
+
+    assert_equal('draft151cm', @context['product.variants[0].title'])
+    assert_equal('element151cm', @context['product.variants[1].title'])
+    assert_equal('draft151cm', @context['product.variants.first.title'])
+    assert_equal('element151cm', @context['product.variants.last.title'])
+  end
+
+  def test_cents
+    @context.merge("cents" => HundredCentes.new)
+    assert_equal(100, @context['cents'])
+  end
+
+  def test_nested_cents
+    @context.merge("cents" => { 'amount' => HundredCentes.new })
+    assert_equal(100, @context['cents.amount'])
+
+    @context.merge("cents" => { 'cents' => { 'amount' => HundredCentes.new } })
+    assert_equal(100, @context['cents.cents.amount'])
+  end
+
+  def test_cents_through_drop
+    @context.merge("cents" => CentsDrop.new)
+    assert_equal(100, @context['cents.amount'])
+  end
+
+  def test_nested_cents_through_drop
+    @context.merge("vars" => { "cents" => CentsDrop.new })
+    assert_equal(100, @context['vars.cents.amount'])
+  end
+
+  def test_drop_methods_with_question_marks
+    @context.merge("cents" => CentsDrop.new)
+    assert(@context['cents.non_zero?'])
+  end
+
+  def test_context_from_within_drop
+    @context.merge("test" => '123', "vars" => ContextSensitiveDrop.new)
+    assert_equal('123', @context['vars.test'])
+  end
+
+  def test_nested_context_from_within_drop
+    @context.merge("test" => '123', "vars" => { "local" => ContextSensitiveDrop.new })
+    assert_equal('123', @context['vars.local.test'])
+  end
+
+  def test_ranges
+    @context.merge("test" => '5')
+    assert_equal((1..5), @context['(1..5)'])
+    assert_equal((1..5), @context['(1..test)'])
+    assert_equal((5..5), @context['(test..test)'])
+  end
+
+  def test_cents_through_drop_nestedly
+    @context.merge("cents" => { "cents" => CentsDrop.new })
+    assert_equal(100, @context['cents.cents.amount'])
+
+    @context.merge("cents" => { "cents" => { "cents" => CentsDrop.new } })
+    assert_equal(100, @context['cents.cents.cents.amount'])
+  end
+
+  def test_drop_with_variable_called_only_once
+    @context['counter'] = CounterDrop.new
+
+    assert_equal(1, @context['counter.count'])
+    assert_equal(2, @context['counter.count'])
+    assert_equal(3, @context['counter.count'])
+  end
+
+  def test_drop_with_key_called_only_once
+    @context['counter'] = CounterDrop.new
+
+    assert_equal(1, @context['counter["count"]'])
+    assert_equal(2, @context['counter["count"]'])
+    assert_equal(3, @context['counter["count"]'])
+  end
+
+  def test_proc_as_variable
+    @context['dynamic'] = proc { 'Hello' }
+
+    assert_equal('Hello', @context['dynamic'])
+  end
+
+  def test_lambda_as_variable
+    @context['dynamic'] = proc { 'Hello' }
+
+    assert_equal('Hello', @context['dynamic'])
+  end
+
+  def test_nested_lambda_as_variable
+    @context['dynamic'] = { "lambda" => proc { 'Hello' } }
+
+    assert_equal('Hello', @context['dynamic.lambda'])
+  end
+
+  def test_array_containing_lambda_as_variable
+    @context['dynamic'] = [1, 2, proc { 'Hello' }, 4, 5]
+
+    assert_equal('Hello', @context['dynamic[2]'])
+  end
+
+  def test_lambda_is_called_once
+    @context['callcount'] = proc {
+      @global ||= 0
+      @global  += 1
+      @global.to_s
+    }
+
+    assert_equal('1', @context['callcount'])
+    assert_equal('1', @context['callcount'])
+    assert_equal('1', @context['callcount'])
+
+    @global = nil
+  end
+
+  def test_nested_lambda_is_called_once
+    @context['callcount'] = { "lambda" => proc {
+                                            @global ||= 0
+                                            @global  += 1
+                                            @global.to_s
+                                          } }
+
+    assert_equal('1', @context['callcount.lambda'])
+    assert_equal('1', @context['callcount.lambda'])
+    assert_equal('1', @context['callcount.lambda'])
+
+    @global = nil
+  end
+
+  def test_lambda_in_array_is_called_once
+    @context['callcount'] = [1, 2, proc {
+                                     @global ||= 0
+                                     @global  += 1
+                                     @global.to_s
+                                   }, 4, 5]
+
+    assert_equal('1', @context['callcount[2]'])
+    assert_equal('1', @context['callcount[2]'])
+    assert_equal('1', @context['callcount[2]'])
+
+    @global = nil
+  end
+
+  def test_access_to_context_from_proc
+    @context.registers[:magic] = 345392
+
+    @context['magic'] = proc { @context.registers[:magic] }
+
+    assert_equal(345392, @context['magic'])
+  end
+
+  def test_to_liquid_and_context_at_first_level
+    @context['category'] = Category.new("foobar")
+    assert_kind_of(CategoryDrop, @context['category'])
+    assert_equal(@context, @context['category'].context)
+  end
+
+  def test_interrupt_avoids_object_allocations
+    @context.interrupt? # ruby 3.0.0 allocates on the first call
+    assert_no_object_allocations do
+      @context.interrupt?
+    end
+  end
+
+  def test_context_initialization_with_a_proc_in_environment
+    contx = Context.new([test: ->(c) { c['poutine'] }], test: :foo)
+
+    assert(contx)
+    assert_nil(contx['poutine'])
+  end
+
+  def test_apply_global_filter
+    global_filter_proc = ->(output) { "#{output} filtered" }
+
+    context = Context.new
+    context.global_filter = global_filter_proc
+
+    assert_equal('hi filtered', context.apply_global_filter('hi'))
+  end
+
+  def test_static_environments_are_read_with_lower_priority_than_environments
+    context = Context.build(
+      static_environments: { 'shadowed' => 'static', 'unshadowed' => 'static' },
+      environments: { 'shadowed' => 'dynamic' }
+    )
+
+    assert_equal('dynamic', context['shadowed'])
+    assert_equal('static', context['unshadowed'])
+  end
+
+  def test_apply_global_filter_when_no_global_filter_exist
+    context = Context.new
+    assert_equal('hi', context.apply_global_filter('hi'))
+  end
+
+  def test_new_isolated_subcontext_does_not_inherit_variables
+    super_context = Context.new
+    super_context['my_variable'] = 'some value'
+    subcontext = super_context.new_isolated_subcontext
+
+    assert_nil(subcontext['my_variable'])
+  end
+
+  def test_new_isolated_subcontext_inherits_static_environment
+    super_context = Context.build(static_environments: { 'my_environment_value' => 'my value' })
+    subcontext    = super_context.new_isolated_subcontext
+
+    assert_equal('my value', subcontext['my_environment_value'])
+  end
+
+  def test_new_isolated_subcontext_inherits_resource_limits
+    resource_limits = ResourceLimits.new({})
+    super_context   = Context.new({}, {}, {}, false, resource_limits)
+    subcontext      = super_context.new_isolated_subcontext
+    assert_equal(resource_limits, subcontext.resource_limits)
+  end
+
+  def test_new_isolated_subcontext_inherits_exception_renderer
+    super_context = Context.new
+    super_context.exception_renderer = ->(_e) { 'my exception message' }
+    subcontext = super_context.new_isolated_subcontext
+    assert_equal('my exception message', subcontext.handle_error(Liquid::Error.new))
+  end
+
+  def test_new_isolated_subcontext_does_not_inherit_non_static_registers
+    registers = {
+      my_register: :my_value,
+    }
+    super_context = Context.new({}, {}, StaticRegisters.new(registers))
+    super_context.registers[:my_register] = :my_alt_value
+    subcontext                            = super_context.new_isolated_subcontext
+    assert_equal(:my_value, subcontext.registers[:my_register])
+  end
+
+  def test_new_isolated_subcontext_inherits_static_registers
+    super_context = Context.build(registers: { my_register: :my_value })
+    subcontext    = super_context.new_isolated_subcontext
+    assert_equal(:my_value, subcontext.registers[:my_register])
+  end
+
+  def test_new_isolated_subcontext_registers_do_not_pollute_context
+    super_context                      = Context.build(registers: { my_register: :my_value })
+    subcontext                         = super_context.new_isolated_subcontext
+    subcontext.registers[:my_register] = :my_alt_value
+    assert_equal(:my_value, super_context.registers[:my_register])
+  end
+
+  def test_new_isolated_subcontext_inherits_filters
+    my_filter = Module.new do
+      def my_filter(*)
+        'my filter result'
+      end
+    end
+
+    super_context = Context.new
+    super_context.add_filters([my_filter])
+    subcontext    = super_context.new_isolated_subcontext
+    template      = Template.parse('{{ 123 | my_filter }}')
+    assert_equal('my filter result', template.render(subcontext))
+  end
+
+  def test_disables_tag_specified
+    context = Context.new
+    context.with_disabled_tags(%w(foo bar)) do
+      assert_equal(true, context.tag_disabled?("foo"))
+      assert_equal(true, context.tag_disabled?("bar"))
+      assert_equal(false, context.tag_disabled?("unknown"))
+    end
+  end
+
+  def test_disables_nested_tags
+    context = Context.new
+    context.with_disabled_tags(["foo"]) do
+      context.with_disabled_tags(["foo"]) do
+        assert_equal(true, context.tag_disabled?("foo"))
+        assert_equal(false, context.tag_disabled?("bar"))
+      end
+      context.with_disabled_tags(["bar"]) do
+        assert_equal(true, context.tag_disabled?("foo"))
+        assert_equal(true, context.tag_disabled?("bar"))
+        context.with_disabled_tags(["foo"]) do
+          assert_equal(true, context.tag_disabled?("foo"))
+          assert_equal(true, context.tag_disabled?("bar"))
+        end
+      end
+      assert_equal(true, context.tag_disabled?("foo"))
+      assert_equal(false, context.tag_disabled?("bar"))
+    end
+  end
+
   def test_override_global_filter
     global = Module.new do
       def notice(output)
@@ -19,16 +607,30 @@ class ContextTest < Minitest::Test
     end
 
     with_global_filter(global) do
-      assert_equal 'Global test', Template.parse("{{'test' | notice }}").render!
-      assert_equal 'Local test', Template.parse("{{'test' | notice }}").render!({}, filters: [local])
+      assert_equal('Global test', Template.parse("{{'test' | notice }}").render!)
+      assert_equal('Local test', Template.parse("{{'test' | notice }}").render!({}, filters: [local]))
     end
   end
 
   def test_has_key_will_not_add_an_error_for_missing_keys
-    with_error_mode :strict do
+    with_error_mode(:strict) do
       context = Context.new
       context.key?('unknown')
-      assert_empty context.errors
+      assert_empty(context.errors)
     end
   end
-end
+
+  private
+
+  def assert_no_object_allocations
+    unless RUBY_ENGINE == 'ruby'
+      skip("stackprof needed to count object allocations")
+    end
+    require 'stackprof'
+
+    profile = StackProf.run(mode: :object) do
+      yield
+    end
+    assert_equal(0, profile[:samples])
+  end
+end # ContextTest

test/integration/document_test.rb

@@ -7,15 +7,15 @@ class DocumentTest < Minitest::Test
 
   def test_unexpected_outer_tag
     exc = assert_raises(SyntaxError) do
-      Template.parse('{% else %}')
+      Template.parse("{% else %}")
     end
-    assert_equal exc.message, "Liquid syntax error: Unexpected outer 'else' tag"
+    assert_equal(exc.message, "Liquid syntax error: Unexpected outer 'else' tag")
   end
 
   def test_unknown_tag
     exc = assert_raises(SyntaxError) do
-      Template.parse('{% foo %}')
+      Template.parse("{% foo %}")
     end
-    assert_equal exc.message, "Liquid syntax error: Unknown tag 'foo'"
+    assert_equal(exc.message, "Liquid syntax error: Unknown tag 'foo'")
   end
 end

test/integration/drop_test.rb

@@ -23,7 +23,7 @@ end
 class ProductDrop < Liquid::Drop
   class TextDrop < Liquid::Drop
     def array
-      %w[text1 text2]
+      ['text1', 'text2']
     end
 
     def text
@@ -33,7 +33,7 @@ class ProductDrop < Liquid::Drop
 
   class CatchallDrop < Liquid::Drop
     def liquid_method_missing(method)
-      +'catchall_method: ' << method.to_s
+      "catchall_method: #{method}"
     end
   end
 
@@ -49,14 +49,10 @@ class ProductDrop < Liquid::Drop
     ContextDrop.new
   end
 
-  def user_input
-    (+'foo').taint
-  end
-
   protected
 
   def callmenot
-    'protected'
+    "protected"
   end
 end
 
@@ -111,165 +107,151 @@ class DropsTest < Minitest::Test
 
   def test_product_drop
     tpl = Liquid::Template.parse('  ')
-    assert_equal '  ', tpl.render!('product' => ProductDrop.new)
-  end
-
-  def test_rendering_raises_on_tainted_attr
-    with_taint_mode(:error) do
-      tpl = Liquid::Template.parse('{{ product.user_input }}')
-      assert_raises TaintedError do
-        tpl.render!('product' => ProductDrop.new)
-      end
-    end
-  end
-
-  def test_rendering_warns_on_tainted_attr
-    with_taint_mode(:warn) do
-      tpl = Liquid::Template.parse('{{ product.user_input }}')
-      context = Context.new('product' => ProductDrop.new)
-      tpl.render!(context)
-      assert_equal [Liquid::TaintedError], context.warnings.map(&:class)
-      assert_equal "variable 'product.user_input' is tainted and was not escaped", context.warnings.first.to_s(false)
-    end
-  end
-
-  def test_rendering_doesnt_raise_on_escaped_tainted_attr
-    with_taint_mode(:error) do
-      tpl = Liquid::Template.parse('{{ product.user_input | escape }}')
-      tpl.render!('product' => ProductDrop.new)
-    end
+    assert_equal('  ', tpl.render!('product' => ProductDrop.new))
   end
 
   def test_drop_does_only_respond_to_whitelisted_methods
-    assert_equal '', Liquid::Template.parse('{{ product.inspect }}').render!('product' => ProductDrop.new)
-    assert_equal '', Liquid::Template.parse('{{ product.pretty_inspect }}').render!('product' => ProductDrop.new)
-    assert_equal '', Liquid::Template.parse('{{ product.whatever }}').render!('product' => ProductDrop.new)
-    assert_equal '', Liquid::Template.parse('{{ product | map: "inspect" }}').render!('product' => ProductDrop.new)
-    assert_equal '', Liquid::Template.parse('{{ product | map: "pretty_inspect" }}').render!('product' => ProductDrop.new)
-    assert_equal '', Liquid::Template.parse('{{ product | map: "whatever" }}').render!('product' => ProductDrop.new)
+    assert_equal("", Liquid::Template.parse("{{ product.inspect }}").render!('product' => ProductDrop.new))
+    assert_equal("", Liquid::Template.parse("{{ product.pretty_inspect }}").render!('product' => ProductDrop.new))
+    assert_equal("", Liquid::Template.parse("{{ product.whatever }}").render!('product' => ProductDrop.new))
+    assert_equal("", Liquid::Template.parse('{{ product | map: "inspect" }}').render!('product' => ProductDrop.new))
+    assert_equal("", Liquid::Template.parse('{{ product | map: "pretty_inspect" }}').render!('product' => ProductDrop.new))
+    assert_equal("", Liquid::Template.parse('{{ product | map: "whatever" }}').render!('product' => ProductDrop.new))
   end
 
   def test_drops_respond_to_to_liquid
-    assert_equal 'text1', Liquid::Template.parse('{{ product.to_liquid.texts.text }}').render!('product' => ProductDrop.new)
-    assert_equal 'text1', Liquid::Template.parse('{{ product | map: "to_liquid" | map: "texts" | map: "text" }}').render!('product' => ProductDrop.new)
+    assert_equal("text1", Liquid::Template.parse("{{ product.to_liquid.texts.text }}").render!('product' => ProductDrop.new))
+    assert_equal("text1", Liquid::Template.parse('{{ product | map: "to_liquid" | map: "texts" | map: "text" }}').render!('product' => ProductDrop.new))
   end
 
   def test_text_drop
     output = Liquid::Template.parse(' {{ product.texts.text }} ').render!('product' => ProductDrop.new)
-    assert_equal ' text1 ', output
+    assert_equal(' text1 ', output)
   end
 
   def test_catchall_unknown_method
     output = Liquid::Template.parse(' {{ product.catchall.unknown }} ').render!('product' => ProductDrop.new)
-    assert_equal ' catchall_method: unknown ', output
+    assert_equal(' catchall_method: unknown ', output)
   end
 
   def test_catchall_integer_argument_drop
     output = Liquid::Template.parse(' {{ product.catchall[8] }} ').render!('product' => ProductDrop.new)
-    assert_equal ' catchall_method: 8 ', output
+    assert_equal(' catchall_method: 8 ', output)
   end
 
   def test_text_array_drop
     output = Liquid::Template.parse('{% for text in product.texts.array %} {{text}} {% endfor %}').render!('product' => ProductDrop.new)
-    assert_equal ' text1  text2 ', output
+    assert_equal(' text1  text2 ', output)
   end
 
   def test_context_drop
-    output = Liquid::Template.parse(' {{ context.bar }} ').render!('context' => ContextDrop.new, 'bar' => 'carrot')
-    assert_equal ' carrot ', output
+    output = Liquid::Template.parse(' {{ context.bar }} ').render!('context' => ContextDrop.new, 'bar' => "carrot")
+    assert_equal(' carrot ', output)
+  end
+
+  def test_context_drop_array_with_map
+    output = Liquid::Template.parse(' {{ contexts | map: "bar" }} ').render!('contexts' => [ContextDrop.new, ContextDrop.new], 'bar' => "carrot")
+    assert_equal(' carrotcarrot ', output)
   end
 
   def test_nested_context_drop
-    output = Liquid::Template.parse(' {{ product.context.foo }} ').render!('product' => ProductDrop.new, 'foo' => 'monkey')
-    assert_equal ' monkey ', output
+    output = Liquid::Template.parse(' {{ product.context.foo }} ').render!('product' => ProductDrop.new, 'foo' => "monkey")
+    assert_equal(' monkey ', output)
   end
 
   def test_protected
     output = Liquid::Template.parse(' {{ product.callmenot }} ').render!('product' => ProductDrop.new)
-    assert_equal '  ', output
+    assert_equal('  ', output)
   end
 
   def test_object_methods_not_allowed
-    %i[dup clone singleton_class eval class_eval inspect].each do |method|
+    [:dup, :clone, :singleton_class, :eval, :class_eval, :inspect].each do |method|
       output = Liquid::Template.parse(" {{ product.#{method} }} ").render!('product' => ProductDrop.new)
-      assert_equal '  ', output
+      assert_equal('  ', output)
     end
   end
 
   def test_scope
-    assert_equal '1', Liquid::Template.parse('{{ context.scopes }}').render!('context' => ContextDrop.new)
-    assert_equal '2', Liquid::Template.parse('{%for i in dummy%}{{ context.scopes }}{%endfor%}').render!('context' => ContextDrop.new, 'dummy' => [1])
-    assert_equal '3', Liquid::Template.parse('{%for i in dummy%}{%for i in dummy%}{{ context.scopes }}{%endfor%}{%endfor%}').render!('context' => ContextDrop.new, 'dummy' => [1])
+    assert_equal('1', Liquid::Template.parse('{{ context.scopes }}').render!('context' => ContextDrop.new))
+    assert_equal('2', Liquid::Template.parse('{%for i in dummy%}{{ context.scopes }}{%endfor%}').render!('context' => ContextDrop.new, 'dummy' => [1]))
+    assert_equal('3', Liquid::Template.parse('{%for i in dummy%}{%for i in dummy%}{{ context.scopes }}{%endfor%}{%endfor%}').render!('context' => ContextDrop.new, 'dummy' => [1]))
   end
 
   def test_scope_though_proc
-    assert_equal '1', Liquid::Template.parse('{{ s }}').render!('context' => ContextDrop.new, 's' => proc { |c| c['context.scopes'] })
-    assert_equal '2', Liquid::Template.parse('{%for i in dummy%}{{ s }}{%endfor%}').render!('context' => ContextDrop.new, 's' => proc { |c| c['context.scopes'] }, 'dummy' => [1])
-    assert_equal '3', Liquid::Template.parse('{%for i in dummy%}{%for i in dummy%}{{ s }}{%endfor%}{%endfor%}').render!('context' => ContextDrop.new, 's' => proc { |c| c['context.scopes'] }, 'dummy' => [1])
+    assert_equal('1', Liquid::Template.parse('{{ s }}').render!('context' => ContextDrop.new, 's' => proc { |c| c['context.scopes'] }))
+    assert_equal('2', Liquid::Template.parse('{%for i in dummy%}{{ s }}{%endfor%}').render!('context' => ContextDrop.new, 's' => proc { |c| c['context.scopes'] }, 'dummy' => [1]))
+    assert_equal('3', Liquid::Template.parse('{%for i in dummy%}{%for i in dummy%}{{ s }}{%endfor%}{%endfor%}').render!('context' => ContextDrop.new, 's' => proc { |c| c['context.scopes'] }, 'dummy' => [1]))
   end
 
   def test_scope_with_assigns
-    assert_equal 'variable', Liquid::Template.parse('{% assign a = "variable"%}{{a}}').render!('context' => ContextDrop.new)
-    assert_equal 'variable', Liquid::Template.parse('{% assign a = "variable"%}{%for i in dummy%}{{a}}{%endfor%}').render!('context' => ContextDrop.new, 'dummy' => [1])
-    assert_equal 'test', Liquid::Template.parse('{% assign header_gif = "test"%}{{header_gif}}').render!('context' => ContextDrop.new)
-    assert_equal 'test', Liquid::Template.parse("{% assign header_gif = 'test'%}{{header_gif}}").render!('context' => ContextDrop.new)
+    assert_equal('variable', Liquid::Template.parse('{% assign a = "variable"%}{{a}}').render!('context' => ContextDrop.new))
+    assert_equal('variable', Liquid::Template.parse('{% assign a = "variable"%}{%for i in dummy%}{{a}}{%endfor%}').render!('context' => ContextDrop.new, 'dummy' => [1]))
+    assert_equal('test', Liquid::Template.parse('{% assign header_gif = "test"%}{{header_gif}}').render!('context' => ContextDrop.new))
+    assert_equal('test', Liquid::Template.parse("{% assign header_gif = 'test'%}{{header_gif}}").render!('context' => ContextDrop.new))
   end
 
   def test_scope_from_tags
-    assert_equal '1', Liquid::Template.parse('{% for i in context.scopes_as_array %}{{i}}{% endfor %}').render!('context' => ContextDrop.new, 'dummy' => [1])
-    assert_equal '12', Liquid::Template.parse('{%for a in dummy%}{% for i in context.scopes_as_array %}{{i}}{% endfor %}{% endfor %}').render!('context' => ContextDrop.new, 'dummy' => [1])
-    assert_equal '123', Liquid::Template.parse('{%for a in dummy%}{%for a in dummy%}{% for i in context.scopes_as_array %}{{i}}{% endfor %}{% endfor %}{% endfor %}').render!('context' => ContextDrop.new, 'dummy' => [1])
+    assert_equal('1', Liquid::Template.parse('{% for i in context.scopes_as_array %}{{i}}{% endfor %}').render!('context' => ContextDrop.new, 'dummy' => [1]))
+    assert_equal('12', Liquid::Template.parse('{%for a in dummy%}{% for i in context.scopes_as_array %}{{i}}{% endfor %}{% endfor %}').render!('context' => ContextDrop.new, 'dummy' => [1]))
+    assert_equal('123', Liquid::Template.parse('{%for a in dummy%}{%for a in dummy%}{% for i in context.scopes_as_array %}{{i}}{% endfor %}{% endfor %}{% endfor %}').render!('context' => ContextDrop.new, 'dummy' => [1]))
   end
 
   def test_access_context_from_drop
-    assert_equal '123', Liquid::Template.parse('{%for a in dummy%}{{ context.loop_pos }}{% endfor %}').render!('context' => ContextDrop.new, 'dummy' => [1, 2, 3])
+    assert_equal('123', Liquid::Template.parse('{%for a in dummy%}{{ context.loop_pos }}{% endfor %}').render!('context' => ContextDrop.new, 'dummy' => [1, 2, 3]))
   end
 
   def test_enumerable_drop
-    assert_equal '123', Liquid::Template.parse('{% for c in collection %}{{c}}{% endfor %}').render!('collection' => EnumerableDrop.new)
+    assert_equal('123', Liquid::Template.parse('{% for c in collection %}{{c}}{% endfor %}').render!('collection' => EnumerableDrop.new))
   end
 
   def test_enumerable_drop_size
-    assert_equal '3', Liquid::Template.parse('{{collection.size}}').render!('collection' => EnumerableDrop.new)
+    assert_equal('3', Liquid::Template.parse('{{collection.size}}').render!('collection' => EnumerableDrop.new))
   end
 
   def test_enumerable_drop_will_invoke_liquid_method_missing_for_clashing_method_names
-    %w[select each map cycle].each do |method|
-      assert_equal method.to_s, Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => EnumerableDrop.new)
-      assert_equal method.to_s, Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => EnumerableDrop.new)
-      assert_equal method.to_s, Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => RealEnumerableDrop.new)
-      assert_equal method.to_s, Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => RealEnumerableDrop.new)
+    ["select", "each", "map", "cycle"].each do |method|
+      assert_equal(method.to_s, Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => EnumerableDrop.new))
+      assert_equal(method.to_s, Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => EnumerableDrop.new))
+      assert_equal(method.to_s, Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => RealEnumerableDrop.new))
+      assert_equal(method.to_s, Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => RealEnumerableDrop.new))
     end
   end
 
   def test_some_enumerable_methods_still_get_invoked
-    %i[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)
-      assert_equal '3', Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => EnumerableDrop.new)
+    [: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))
+      assert_equal("3", Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => EnumerableDrop.new))
     end
 
-    assert_equal 'yes', Liquid::Template.parse('{% if collection contains 3 %}yes{% endif %}').render!('collection' => RealEnumerableDrop.new)
+    assert_equal("yes", Liquid::Template.parse("{% if collection contains 3 %}yes{% endif %}").render!('collection' => RealEnumerableDrop.new))
 
-    %i[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)
-      assert_equal '1', Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => EnumerableDrop.new)
+    [: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))
+      assert_equal("1", Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => EnumerableDrop.new))
     end
   end
 
   def test_empty_string_value_access
-    assert_equal '', Liquid::Template.parse('{{ product[value] }}').render!('product' => ProductDrop.new, 'value' => '')
+    assert_equal('', Liquid::Template.parse('{{ product[value] }}').render!('product' => ProductDrop.new, 'value' => ''))
   end
 
   def test_nil_value_access
-    assert_equal '', Liquid::Template.parse('{{ product[value] }}').render!('product' => ProductDrop.new, 'value' => nil)
+    assert_equal('', Liquid::Template.parse('{{ product[value] }}').render!('product' => ProductDrop.new, 'value' => nil))
   end
 
   def test_default_to_s_on_drops
-    assert_equal 'ProductDrop', Liquid::Template.parse('{{ product }}').render!('product' => ProductDrop.new)
-    assert_equal 'EnumerableDrop', Liquid::Template.parse('{{ collection }}').render!('collection' => EnumerableDrop.new)
+    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 context texts).to_set, ProductDrop.invokable_methods)
+    assert_equal(%w(to_liquid scopes_as_array loop_pos scopes).to_set, ContextDrop.invokable_methods)
+    assert_equal(%w(to_liquid size max min first count).to_set, EnumerableDrop.invokable_methods)
+    assert_equal(%w(to_liquid max min sort count first).to_set, RealEnumerableDrop.invokable_methods)
   end
 end # DropsTest

test/integration/error_handling_test.rb

@@ -35,31 +35,31 @@ class ErrorHandlingTest < Minitest::Test
     TEXT
 
     output = Liquid::Template.parse(template, line_numbers: true).render('errors' => ErrorDrop.new)
-    assert_equal expected, output
+    assert_equal(expected, output)
   end
 
   def test_standard_error
     template = Liquid::Template.parse(' {{ errors.standard_error }} ')
-    assert_equal ' Liquid error: standard error ', template.render('errors' => ErrorDrop.new)
+    assert_equal(' Liquid error: standard error ', template.render('errors' => ErrorDrop.new))
 
-    assert_equal 1, template.errors.size
-    assert_equal StandardError, template.errors.first.class
+    assert_equal(1, template.errors.size)
+    assert_equal(StandardError, template.errors.first.class)
   end
 
   def test_syntax
     template = Liquid::Template.parse(' {{ errors.syntax_error }} ')
-    assert_equal ' Liquid syntax error: syntax error ', template.render('errors' => ErrorDrop.new)
+    assert_equal(' Liquid syntax error: syntax error ', template.render('errors' => ErrorDrop.new))
 
-    assert_equal 1, template.errors.size
-    assert_equal SyntaxError, template.errors.first.class
+    assert_equal(1, template.errors.size)
+    assert_equal(SyntaxError, template.errors.first.class)
   end
 
   def test_argument
     template = Liquid::Template.parse(' {{ errors.argument_error }} ')
-    assert_equal ' Liquid error: argument error ', template.render('errors' => ErrorDrop.new)
+    assert_equal(' Liquid error: argument error ', template.render('errors' => ErrorDrop.new))
 
-    assert_equal 1, template.errors.size
-    assert_equal ArgumentError, template.errors.first.class
+    assert_equal(1, template.errors.size)
+    assert_equal(ArgumentError, template.errors.first.class)
   end
 
   def test_missing_endtag_parse_time_error
@@ -78,9 +78,9 @@ class ErrorHandlingTest < Minitest::Test
 
   def test_lax_unrecognized_operator
     template = Liquid::Template.parse(' {% if 1 =! 2 %}ok{% endif %} ', error_mode: :lax)
-    assert_equal ' Liquid error: Unknown operator =! ', template.render
-    assert_equal 1, template.errors.size
-    assert_equal Liquid::ArgumentError, template.errors.first.class
+    assert_equal(' Liquid error: Unknown operator =! ', template.render)
+    assert_equal(1, template.errors.size)
+    assert_equal(Liquid::ArgumentError, template.errors.first.class)
   end
 
   def test_with_line_numbers_adds_numbers_to_parser_errors
@@ -92,7 +92,7 @@ class ErrorHandlingTest < Minitest::Test
 
           bla
         ',
-                             line_numbers: true)
+        line_numbers: true)
     end
 
     assert_match(/Liquid syntax error \(line 4\)/, err.message)
@@ -107,7 +107,7 @@ class ErrorHandlingTest < Minitest::Test
 
           bla
         ',
-                             line_numbers: true)
+        line_numbers: true)
     end
 
     assert_match(/Liquid syntax error \(line 4\)/, err.message)
@@ -121,11 +121,11 @@ class ErrorHandlingTest < Minitest::Test
 
         bla
             ',
-                                      error_mode: :warn,
-                                      line_numbers: true)
+      error_mode: :warn,
+      line_numbers: true)
 
-    assert_equal ['Liquid syntax error (line 4): Unexpected character = in "1 =! 2"'],
-                 template.warnings.map(&:message)
+    assert_equal(['Liquid syntax error (line 4): Unexpected character = in "1 =! 2"'],
+      template.warnings.map(&:message))
   end
 
   def test_parsing_strict_with_line_numbers_adds_numbers_to_lexer_errors
@@ -137,11 +137,11 @@ class ErrorHandlingTest < Minitest::Test
 
           bla
                 ',
-                             error_mode: :strict,
-                             line_numbers: true)
+        error_mode: :strict,
+        line_numbers: true)
     end
 
-    assert_equal 'Liquid syntax error (line 4): Unexpected character = in "1 =! 2"', err.message
+    assert_equal('Liquid syntax error (line 4): Unexpected character = in "1 =! 2"', err.message)
   end
 
   def test_syntax_errors_in_nested_blocks_have_correct_line_number
@@ -155,45 +155,45 @@ class ErrorHandlingTest < Minitest::Test
 
           bla
                 ',
-                             line_numbers: true)
+        line_numbers: true)
     end
 
-    assert_equal "Liquid syntax error (line 5): Unknown tag 'foo'", err.message
+    assert_equal("Liquid syntax error (line 5): Unknown tag 'foo'", err.message)
   end
 
   def test_strict_error_messages
     err = assert_raises(SyntaxError) do
       Liquid::Template.parse(' {% if 1 =! 2 %}ok{% endif %} ', error_mode: :strict)
     end
-    assert_equal 'Liquid syntax error: Unexpected character = in "1 =! 2"', err.message
+    assert_equal('Liquid syntax error: Unexpected character = in "1 =! 2"', err.message)
 
     err = assert_raises(SyntaxError) do
       Liquid::Template.parse('{{%%%}}', error_mode: :strict)
     end
-    assert_equal 'Liquid syntax error: Unexpected character % in "{{%%%}}"', err.message
+    assert_equal('Liquid syntax error: Unexpected character % in "{{%%%}}"', err.message)
   end
 
   def test_warnings
     template = Liquid::Template.parse('{% if ~~~ %}{{%%%}}{% else %}{{ hello. }}{% endif %}', error_mode: :warn)
-    assert_equal 3, template.warnings.size
-    assert_equal 'Unexpected character ~ in "~~~"', template.warnings[0].to_s(false)
-    assert_equal 'Unexpected character % in "{{%%%}}"', template.warnings[1].to_s(false)
-    assert_equal 'Expected id but found end_of_string in "{{ hello. }}"', template.warnings[2].to_s(false)
-    assert_equal '', template.render
+    assert_equal(3, template.warnings.size)
+    assert_equal('Unexpected character ~ in "~~~"', template.warnings[0].to_s(false))
+    assert_equal('Unexpected character % in "{{%%%}}"', template.warnings[1].to_s(false))
+    assert_equal('Expected id but found end_of_string in "{{ hello. }}"', template.warnings[2].to_s(false))
+    assert_equal('', template.render)
   end
 
   def test_warning_line_numbers
     template = Liquid::Template.parse("{% if ~~~ %}\n{{%%%}}{% else %}\n{{ hello. }}{% endif %}", error_mode: :warn, line_numbers: true)
-    assert_equal 'Liquid syntax error (line 1): Unexpected character ~ in "~~~"', template.warnings[0].message
-    assert_equal 'Liquid syntax error (line 2): Unexpected character % in "{{%%%}}"', template.warnings[1].message
-    assert_equal 'Liquid syntax error (line 3): Expected id but found end_of_string in "{{ hello. }}"', template.warnings[2].message
-    assert_equal 3, template.warnings.size
-    assert_equal [1, 2, 3], template.warnings.map(&:line_number)
+    assert_equal('Liquid syntax error (line 1): Unexpected character ~ in "~~~"', template.warnings[0].message)
+    assert_equal('Liquid syntax error (line 2): Unexpected character % in "{{%%%}}"', template.warnings[1].message)
+    assert_equal('Liquid syntax error (line 3): Expected id but found end_of_string in "{{ hello. }}"', template.warnings[2].message)
+    assert_equal(3, template.warnings.size)
+    assert_equal([1, 2, 3], template.warnings.map(&:line_number))
   end
 
   # Liquid should not catch Exceptions that are not subclasses of StandardError, like Interrupt and NoMemoryError
   def test_exceptions_propagate
-    assert_raises Exception do
+    assert_raises(Exception) do
       template = Liquid::Template.parse('{{ errors.exception }}')
       template.render('errors' => ErrorDrop.new)
     end
@@ -204,14 +204,14 @@ class ErrorHandlingTest < Minitest::Test
 
     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)
+    assert_equal('This is a runtime error: Liquid error (line 1): internal', output)
+    assert_equal([Liquid::InternalError], template.errors.map(&:class))
   end
 
   def test_setting_default_exception_renderer
     old_exception_renderer = Liquid::Template.default_exception_renderer
     exceptions = []
-    Liquid::Template.default_exception_renderer = lambda { |e|
+    Liquid::Template.default_exception_renderer = ->(e) {
       exceptions << e
       ''
     }
@@ -219,31 +219,31 @@ class ErrorHandlingTest < Minitest::Test
 
     output = template.render('errors' => ErrorDrop.new)
 
-    assert_equal 'This is a runtime error: ', output
-    assert_equal [Liquid::ArgumentError], template.errors.map(&:class)
+    assert_equal('This is a runtime error: ', output)
+    assert_equal([Liquid::ArgumentError], template.errors.map(&:class))
   ensure
     Liquid::Template.default_exception_renderer = old_exception_renderer if old_exception_renderer
   end
 
   def test_exception_renderer_exposing_non_liquid_error
-    template = Liquid::Template.parse('This is a runtime error: {{ errors.runtime_error }}', line_numbers: true)
+    template   = Liquid::Template.parse('This is a runtime error: {{ errors.runtime_error }}', line_numbers: true)
     exceptions = []
-    handler = lambda { |e|
+    handler    = ->(e) {
       exceptions << e
       e.cause
     }
 
     output = template.render({ 'errors' => ErrorDrop.new }, exception_renderer: handler)
 
-    assert_equal 'This is a runtime error: runtime error', output
-    assert_equal [Liquid::InternalError], exceptions.map(&:class)
-    assert_equal exceptions, template.errors
-    assert_equal '#<RuntimeError: runtime error>', exceptions.first.cause.inspect
+    assert_equal('This is a runtime error: runtime error', output)
+    assert_equal([Liquid::InternalError], exceptions.map(&:class))
+    assert_equal(exceptions, template.errors)
+    assert_equal('#<RuntimeError: runtime error>', exceptions.first.cause.inspect)
   end
 
   class TestFileSystem
     def read_template_file(_template_path)
-      '{{ errors.argument_error }}'
+      "{{ errors.argument_error }}"
     end
   end
 
@@ -252,12 +252,21 @@ class ErrorHandlingTest < Minitest::Test
 
     begin
       Liquid::Template.file_system = TestFileSystem.new
+
       template = Liquid::Template.parse("Argument error:\n{% include 'product' %}", line_numbers: true)
-      page = template.render('errors' => ErrorDrop.new)
+      page     = template.render('errors' => ErrorDrop.new)
     ensure
       Liquid::Template.file_system = old_file_system
     end
-    assert_equal "Argument error:\nLiquid error (product line 1): argument error", page
-    assert_equal 'product', template.errors.first.template_name
+    assert_equal("Argument error:\nLiquid error (product line 1): argument error", page)
+    assert_equal("product", template.errors.first.template_name)
+  end
+
+  def test_bug_compatible_silencing_of_errors_in_blank_nodes
+    output = Liquid::Template.parse("{% assign x = 0 %}{% if 1 < '2' %}not blank{% assign x = 3 %}{% endif %}{{ x }}").render
+    assert_equal("Liquid error: comparison of Integer with String failed0", output)
+
+    output = Liquid::Template.parse("{% assign x = 0 %}{% if 1 < '2' %}{% assign x = 3 %}{% endif %}{{ x }}").render
+    assert_equal("0", output)
   end
 end

test/integration/expression_test.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class ExpressionTest < Minitest::Test
+  def test_keyword_literals
+    assert_equal(true, parse_and_eval("true"))
+    assert_equal(true, parse_and_eval(" true "))
+  end
+
+  def test_string
+    assert_equal("single quoted", parse_and_eval("'single quoted'"))
+    assert_equal("double quoted", parse_and_eval('"double quoted"'))
+    assert_equal("spaced", parse_and_eval(" 'spaced' "))
+    assert_equal("spaced2", parse_and_eval(' "spaced2" '))
+  end
+
+  def test_int
+    assert_equal(123, parse_and_eval("123"))
+    assert_equal(456, parse_and_eval(" 456 "))
+    assert_equal(12, parse_and_eval("012"))
+  end
+
+  def test_float
+    assert_equal(1.5, parse_and_eval("1.5"))
+    assert_equal(2.5, parse_and_eval(" 2.5 "))
+  end
+
+  def test_range
+    assert_equal(1..2, parse_and_eval("(1..2)"))
+    assert_equal(3..4, parse_and_eval(" ( 3 .. 4 ) "))
+  end
+
+  private
+
+  def parse_and_eval(markup, **assigns)
+    if Liquid::Template.error_mode == :strict
+      p = Liquid::Parser.new(markup)
+      markup = p.expression
+      p.consume(:end_of_string)
+    end
+    expression = Liquid::Expression.parse(markup)
+    context = Liquid::Context.new(assigns)
+    context.evaluate(expression)
+  end
+end

test/integration/filter_test.rb

@@ -29,7 +29,7 @@ class FiltersTest < Minitest::Test
 
   module OverrideObjectMethodFilter
     def tap(_input)
-      'tap overridden'
+      "tap overridden"
     end
   end
 
@@ -41,13 +41,13 @@ class FiltersTest < Minitest::Test
     @context['var'] = 1000
     @context.add_filters(MoneyFilter)
 
-    assert_equal ' 1000$ ', Template.parse('{{var | money}}').render(@context)
+    assert_equal(' 1000$ ', Template.parse("{{var | money}}").render(@context))
   end
 
   def test_underscore_in_filter_name
     @context['var'] = 1000
     @context.add_filters(MoneyFilter)
-    assert_equal ' 1000$ ', Template.parse('{{var | money_with_underscore}}').render(@context)
+    assert_equal(' 1000$ ', Template.parse("{{var | money_with_underscore}}").render(@context))
   end
 
   def test_second_filter_overwrites_first
@@ -55,103 +55,112 @@ class FiltersTest < Minitest::Test
     @context.add_filters(MoneyFilter)
     @context.add_filters(CanadianMoneyFilter)
 
-    assert_equal ' 1000$ CAD ', Template.parse('{{var | money}}').render(@context)
+    assert_equal(' 1000$ CAD ', Template.parse("{{var | money}}").render(@context))
   end
 
   def test_size
     @context['var'] = 'abcd'
     @context.add_filters(MoneyFilter)
 
-    assert_equal '4', Template.parse('{{var | size}}').render(@context)
+    assert_equal('4', Template.parse("{{var | size}}").render(@context))
   end
 
   def test_join
     @context['var'] = [1, 2, 3, 4]
 
-    assert_equal '1 2 3 4', Template.parse('{{var | join}}').render(@context)
+    assert_equal("1 2 3 4", Template.parse("{{var | join}}").render(@context))
   end
 
   def test_sort
-    @context['value'] = 3
+    @context['value']   = 3
     @context['numbers'] = [2, 1, 4, 3]
-    @context['words'] = %w[expected as alphabetic]
-    @context['arrays'] = %w[flower are]
-    @context['case_sensitive'] = %w[sensitive Expected case]
+    @context['words']   = ['expected', 'as', 'alphabetic']
+    @context['arrays']  = ['flower', 'are']
+    @context['case_sensitive'] = ['sensitive', 'Expected', 'case']
 
-    assert_equal '1 2 3 4', Template.parse('{{numbers | sort | join}}').render(@context)
-    assert_equal 'alphabetic as expected', Template.parse('{{words | sort | join}}').render(@context)
-    assert_equal '3', Template.parse('{{value | sort}}').render(@context)
-    assert_equal 'are flower', Template.parse('{{arrays | sort | join}}').render(@context)
-    assert_equal 'Expected case sensitive', Template.parse('{{case_sensitive | sort | join}}').render(@context)
+    assert_equal('1 2 3 4', Template.parse("{{numbers | sort | join}}").render(@context))
+    assert_equal('alphabetic as expected', Template.parse("{{words | sort | join}}").render(@context))
+    assert_equal('3', Template.parse("{{value | sort}}").render(@context))
+    assert_equal('are flower', Template.parse("{{arrays | sort | join}}").render(@context))
+    assert_equal('Expected case sensitive', Template.parse("{{case_sensitive | sort | join}}").render(@context))
   end
 
   def test_sort_natural
-    @context['words'] = %w[case Assert Insensitive]
-    @context['hashes'] = [{ 'a' => 'A' }, { 'a' => 'b' }, { 'a' => 'C' }]
+    @context['words']   = ['case', 'Assert', 'Insensitive']
+    @context['hashes']  = [{ 'a' => 'A' }, { 'a' => 'b' }, { 'a' => 'C' }]
     @context['objects'] = [TestObject.new('A'), TestObject.new('b'), TestObject.new('C')]
 
     # Test strings
-    assert_equal 'Assert case Insensitive', Template.parse('{{words | sort_natural | join}}').render(@context)
+    assert_equal('Assert case Insensitive', Template.parse("{{words | sort_natural | join}}").render(@context))
 
     # Test hashes
-    assert_equal 'A b C', Template.parse("{{hashes | sort_natural: 'a' | map: 'a' | join}}").render(@context)
+    assert_equal('A b C', Template.parse("{{hashes | sort_natural: 'a' | map: 'a' | join}}").render(@context))
 
     # Test objects
-    assert_equal 'A b C', Template.parse("{{objects | sort_natural: 'a' | map: 'a' | join}}").render(@context)
+    assert_equal('A b C', Template.parse("{{objects | sort_natural: 'a' | map: 'a' | join}}").render(@context))
   end
 
   def test_compact
-    @context['words'] = ['a', nil, 'b', nil, 'c']
-    @context['hashes'] = [{ 'a' => 'A' }, { 'a' => nil }, { 'a' => 'C' }]
+    @context['words']   = ['a', nil, 'b', nil, 'c']
+    @context['hashes']  = [{ 'a' => 'A' }, { 'a' => nil }, { 'a' => 'C' }]
     @context['objects'] = [TestObject.new('A'), TestObject.new(nil), TestObject.new('C')]
 
     # Test strings
-    assert_equal 'a b c', Template.parse('{{words | compact | join}}').render(@context)
+    assert_equal('a b c', Template.parse("{{words | compact | join}}").render(@context))
 
     # Test hashes
-    assert_equal 'A C', Template.parse("{{hashes | compact: 'a' | map: 'a' | join}}").render(@context)
+    assert_equal('A C', Template.parse("{{hashes | compact: 'a' | map: 'a' | join}}").render(@context))
 
     # Test objects
-    assert_equal 'A C', Template.parse("{{objects | compact: 'a' | map: 'a' | join}}").render(@context)
+    assert_equal('A C', Template.parse("{{objects | compact: 'a' | map: 'a' | join}}").render(@context))
   end
 
   def test_strip_html
-    @context['var'] = '<b>bla blub</a>'
+    @context['var'] = "<b>bla blub</a>"
 
-    assert_equal 'bla blub', Template.parse('{{ var | strip_html }}').render(@context)
+    assert_equal("bla blub", Template.parse("{{ var | strip_html }}").render(@context))
   end
 
   def test_strip_html_ignore_comments_with_html
-    @context['var'] = '<!-- split and some <ul> tag --><b>bla blub</a>'
+    @context['var'] = "<!-- split and some <ul> tag --><b>bla blub</a>"
 
-    assert_equal 'bla blub', Template.parse('{{ var | strip_html }}').render(@context)
+    assert_equal("bla blub", Template.parse("{{ var | strip_html }}").render(@context))
   end
 
   def test_capitalize
-    @context['var'] = 'blub'
+    @context['var'] = "blub"
 
-    assert_equal 'Blub', Template.parse('{{ var | capitalize }}').render(@context)
+    assert_equal("Blub", Template.parse("{{ var | capitalize }}").render(@context))
   end
 
   def test_nonexistent_filter_is_ignored
     @context['var'] = 1000
 
-    assert_equal '1000', Template.parse('{{ var | xyzzy }}').render(@context)
+    assert_equal('1000', Template.parse("{{ var | xyzzy }}").render(@context))
   end
 
   def test_filter_with_keyword_arguments
     @context['surname'] = 'john'
-    @context['input'] = 'hello %{first_name}, %{last_name}'
+    @context['input']   = 'hello %{first_name}, %{last_name}'
     @context.add_filters(SubstituteFilter)
-    output = Template.parse(%({{ input | substitute: first_name: surname, last_name: 'doe' }})).render(@context)
-    assert_equal 'hello john, doe', output
+    output              = Template.parse(%({{ input | substitute: first_name: surname, last_name: 'doe' }})).render(@context)
+    assert_equal('hello john, doe', output)
   end
 
   def test_override_object_method_in_filter
-    assert_equal 'tap overridden', Template.parse('{{var | tap}}').render!({ 'var' => 1000 }, filters: [OverrideObjectMethodFilter])
+    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
+
+  def test_liquid_argument_error
+    source = "{{ '' | size: 'too many args' }}"
+    exc = assert_raises(Liquid::ArgumentError) do
+      Template.parse(source).render!
+    end
+    assert_match(/\ALiquid error: wrong number of arguments /, exc.message)
+    assert_equal(exc.message, Template.parse(source).render)
   end
 end
 
@@ -160,15 +169,15 @@ class FiltersInTemplate < Minitest::Test
 
   def test_local_global
     with_global_filter(MoneyFilter) do
-      assert_equal ' 1000$ ', Template.parse('{{1000 | money}}').render!(nil, nil)
-      assert_equal ' 1000$ CAD ', Template.parse('{{1000 | money}}').render!(nil, filters: CanadianMoneyFilter)
-      assert_equal ' 1000$ CAD ', Template.parse('{{1000 | money}}').render!(nil, filters: [CanadianMoneyFilter])
+      assert_equal(" 1000$ ", Template.parse("{{1000 | money}}").render!(nil, nil))
+      assert_equal(" 1000$ CAD ", Template.parse("{{1000 | money}}").render!(nil, filters: CanadianMoneyFilter))
+      assert_equal(" 1000$ CAD ", Template.parse("{{1000 | money}}").render!(nil, filters: [CanadianMoneyFilter]))
     end
   end
 
   def test_local_filter_with_deprecated_syntax
-    assert_equal ' 1000$ CAD ', Template.parse('{{1000 | money}}').render!(nil, CanadianMoneyFilter)
-    assert_equal ' 1000$ CAD ', Template.parse('{{1000 | money}}').render!(nil, [CanadianMoneyFilter])
+    assert_equal(" 1000$ CAD ", Template.parse("{{1000 | money}}").render!(nil, CanadianMoneyFilter))
+    assert_equal(" 1000$ CAD ", Template.parse("{{1000 | money}}").render!(nil, [CanadianMoneyFilter]))
   end
 end # FiltersTest
 

test/integration/hash_ordering_test.rb

@@ -19,7 +19,7 @@ class HashOrderingTest < Minitest::Test
 
   def test_global_register_order
     with_global_filter(MoneyFilter, CanadianMoneyFilter) do
-      assert_equal ' 1000$ CAD ', Template.parse('{{1000 | money}}').render(nil, nil)
+      assert_equal(" 1000$ CAD ", Template.parse("{{1000 | money}}").render(nil, nil))
     end
   end
 end

test/integration/legacy_test.rb

@@ -1,13 +0,0 @@
-# frozen_string_literal: true
-
-require 'test_helper'
-require 'liquid/legacy'
-
-class FiltersTest < Minitest::Test
-  include Liquid
-
-  def test_constants
-    assert_equal Liquid::FilterSeparator, Liquid::FILTER_SEPARATOR
-    assert_equal Liquid::BlockBody::ContentOfVariable, Liquid::BlockBody::CONTENT_OF_VARIABLE
-  end
-end

test/integration/output_test.rb

@@ -11,11 +11,11 @@ module FunnyFilter
     "LOL: #{input}"
   end
 
-  def add_smiley(input, smiley = ':-)')
+  def add_smiley(input, smiley = ":-)")
     "#{input} #{smiley}"
   end
 
-  def add_tag(input, tag = 'p', id = 'foo')
+  def add_tag(input, tag = "p", id = "foo")
     %(<#{tag} id="#{id}">#{input}</#{tag}>)
   end
 
@@ -42,84 +42,84 @@ class OutputTest < Minitest::Test
     text = %( {{best_cars}} )
 
     expected = %( bmw )
-    assert_equal expected, Template.parse(text).render!(@assigns)
+    assert_equal(expected, Template.parse(text).render!(@assigns))
   end
 
   def test_variable_traversing_with_two_brackets
     text = %({{ site.data.menu[include.menu][include.locale] }})
-    assert_equal 'it works!', Template.parse(text).render!(
-      'site' => { 'data' => { 'menu' => { 'foo' => { 'bar' => 'it works!' } } } },
-      'include' => { 'menu' => 'foo', 'locale' => 'bar' }
-    )
+    assert_equal("it works!", Template.parse(text).render!(
+      "site" => { "data" => { "menu" => { "foo" => { "bar" => "it works!" } } } },
+      "include" => { "menu" => "foo", "locale" => "bar" }
+    ))
   end
 
   def test_variable_traversing
     text = %( {{car.bmw}} {{car.gm}} {{car.bmw}} )
 
     expected = %( good bad good )
-    assert_equal expected, Template.parse(text).render!(@assigns)
+    assert_equal(expected, Template.parse(text).render!(@assigns))
   end
 
   def test_variable_piping
-    text = %( {{ car.gm | make_funny }} )
+    text     = %( {{ car.gm | make_funny }} )
     expected = %( LOL )
 
-    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+    assert_equal(expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter]))
   end
 
   def test_variable_piping_with_input
-    text = %( {{ car.gm | cite_funny }} )
+    text     = %( {{ car.gm | cite_funny }} )
     expected = %( LOL: bad )
 
-    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+    assert_equal(expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter]))
   end
 
   def test_variable_piping_with_args
-    text = %! {{ car.gm | add_smiley : ':-(' }} !
+    text     = %! {{ car.gm | add_smiley : ':-(' }} !
     expected = %| bad :-( |
 
-    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+    assert_equal(expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter]))
   end
 
   def test_variable_piping_with_no_args
-    text = %( {{ car.gm | add_smiley }} )
+    text     = %( {{ car.gm | add_smiley }} )
     expected = %| bad :-) |
 
-    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+    assert_equal(expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter]))
   end
 
   def test_multiple_variable_piping_with_args
-    text = %! {{ car.gm | add_smiley : ':-(' | add_smiley : ':-('}} !
+    text     = %! {{ car.gm | add_smiley : ':-(' | add_smiley : ':-('}} !
     expected = %| bad :-( :-( |
 
-    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+    assert_equal(expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter]))
   end
 
   def test_variable_piping_with_multiple_args
-    text = %( {{ car.gm | add_tag : 'span', 'bar'}} )
+    text     = %( {{ car.gm | add_tag : 'span', 'bar'}} )
     expected = %( <span id="bar">bad</span> )
 
-    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+    assert_equal(expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter]))
   end
 
   def test_variable_piping_with_variable_args
-    text = %( {{ car.gm | add_tag : 'span', car.bmw}} )
+    text     = %( {{ car.gm | add_tag : 'span', car.bmw}} )
     expected = %( <span id="good">bad</span> )
 
-    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+    assert_equal(expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter]))
   end
 
   def test_multiple_pipings
-    text = %( {{ best_cars | cite_funny | paragraph }} )
+    text     = %( {{ best_cars | cite_funny | paragraph }} )
     expected = %( <p>LOL: bmw</p> )
 
-    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+    assert_equal(expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter]))
   end
 
   def test_link_to
-    text = %( {{ 'Typo' | link_to: 'http://typo.leetsoft.com' }} )
+    text     = %( {{ 'Typo' | link_to: 'http://typo.leetsoft.com' }} )
     expected = %( <a href="http://typo.leetsoft.com">Typo</a> )
 
-    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+    assert_equal(expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter]))
   end
 end # OutputTest

test/integration/parsing_quirks_test.rb

@@ -6,38 +6,38 @@ class ParsingQuirksTest < Minitest::Test
   include Liquid
 
   def test_parsing_css
-    text = ' div { font-weight: bold; } '
-    assert_equal text, Template.parse(text).render!
+    text = " div { font-weight: bold; } "
+    assert_equal(text, Template.parse(text).render!)
   end
 
   def test_raise_on_single_close_bracet
     assert_raises(SyntaxError) do
-      Template.parse('text {{method} oh nos!')
+      Template.parse("text {{method} oh nos!")
     end
   end
 
   def test_raise_on_label_and_no_close_bracets
     assert_raises(SyntaxError) do
-      Template.parse('TEST {{ ')
+      Template.parse("TEST {{ ")
     end
   end
 
   def test_raise_on_label_and_no_close_bracets_percent
     assert_raises(SyntaxError) do
-      Template.parse('TEST {% ')
+      Template.parse("TEST {% ")
     end
   end
 
   def test_error_on_empty_filter
-    assert Template.parse('{{test}}')
+    assert(Template.parse("{{test}}"))
 
     with_error_mode(:lax) do
-      assert Template.parse('{{|test}}')
+      assert(Template.parse("{{|test}}"))
     end
 
     with_error_mode(:strict) do
-      assert_raises(SyntaxError) { Template.parse('{{|test}}') }
-      assert_raises(SyntaxError) { Template.parse('{{test |a|b|}}') }
+      assert_raises(SyntaxError) { Template.parse("{{|test}}") }
+      assert_raises(SyntaxError) { Template.parse("{{test |a|b|}}") }
     end
   end
 
@@ -53,35 +53,35 @@ class ParsingQuirksTest < Minitest::Test
   def test_unexpected_characters_syntax_error
     with_error_mode(:strict) do
       assert_raises(SyntaxError) do
-        markup = 'true && false'
+        markup = "true && false"
         Template.parse("{% if #{markup} %} YES {% endif %}")
       end
       assert_raises(SyntaxError) do
-        markup = 'false || true'
+        markup = "false || true"
         Template.parse("{% if #{markup} %} YES {% endif %}")
       end
     end
   end
 
   def test_no_error_on_lax_empty_filter
-    assert Template.parse('{{test |a|b|}}', error_mode: :lax)
-    assert Template.parse('{{test}}', error_mode: :lax)
-    assert Template.parse('{{|test|}}', error_mode: :lax)
+    assert(Template.parse("{{test |a|b|}}", error_mode: :lax))
+    assert(Template.parse("{{test}}", error_mode: :lax))
+    assert(Template.parse("{{|test|}}", error_mode: :lax))
   end
 
   def test_meaningless_parens_lax
     with_error_mode(:lax) do
       assigns = { 'b' => 'bar', 'c' => 'baz' }
-      markup = "a == 'foo' or (b == 'bar' and c == 'baz') or false"
+      markup  = "a == 'foo' or (b == 'bar' and c == 'baz') or false"
       assert_template_result(' YES ', "{% if #{markup} %} YES {% endif %}", assigns)
     end
   end
 
   def test_unexpected_characters_silently_eat_logic_lax
     with_error_mode(:lax) do
-      markup = 'true && false'
+      markup = "true && false"
       assert_template_result(' YES ', "{% if #{markup} %} YES {% endif %}")
-      markup = 'false || true'
+      markup = "false || true"
       assert_template_result('', "{% if #{markup} %} YES {% endif %}")
     end
   end
@@ -114,10 +114,20 @@ class ParsingQuirksTest < Minitest::Test
 
   def test_extra_dots_in_ranges
     with_error_mode(:lax) do
-      assert_template_result('12345', '{% for i in (1...5) %}{{ i }}{% endfor %}')
+      assert_template_result('12345', "{% for i in (1...5) %}{{ i }}{% endfor %}")
     end
   end
 
+  def test_blank_variable_markup
+    assert_template_result('', "{{}}")
+  end
+
+  def test_lookup_on_var_with_literal_name
+    assigns = { "blank" => { "x" => "result" } }
+    assert_template_result('result', "{{ blank.x }}", assigns)
+    assert_template_result('result', "{{ blank['x'] }}", assigns)
+  end
+
   def test_contains_in_id
     assert_template_result(' YES ', '{% if containsallshipments == true %} YES {% endif %}', 'containsallshipments' => true)
   end