Merge pull request #1905 from Shopify/catlee/invalid_utf8

Raise SyntaxError on invalid UTF8 strings in lexer/tokenizer

.github/workflows/liquid.yml

@@ -11,9 +11,11 @@ jobs:
     strategy:
       matrix:
         entry:
-          - { ruby: 2.7, allowed-failure: false } # minimum supported
+          - { ruby: 3.0, allowed-failure: false } # minimum supported
-          - { ruby: 3.2, allowed-failure: false } # latest
+          - { ruby: 3.2, allowed-failure: false }
-          - { ruby: ruby-head, allowed-failure: true }
+          - { ruby: 3.3, allowed-failure: false }
+          - { ruby: 3.4, allowed-failure: false } # latest
+          - { ruby: ruby-head, allowed-failure: false }
     name: Test Ruby ${{ matrix.entry.ruby }}
     steps:
       - uses: actions/checkout@v3
@@ -21,6 +23,7 @@ jobs:
         with:
           ruby-version: ${{ matrix.entry.ruby }}
           bundler-cache: true
+          bundler: latest
       - run: bundle exec rake
         continue-on-error: ${{ matrix.entry.allowed-failure }}
 
@@ -30,6 +33,5 @@ jobs:
       - uses: actions/checkout@v3
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: 2.7
           bundler-cache: true
       - run: bundle exec rake memory_profile:run

.gitignore

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

.rubocop.yml

@@ -10,7 +10,6 @@ Performance:
   Enabled: true
 
 AllCops:
-  TargetRubyVersion: 2.7
   NewCops: disable
   SuggestExtensions: false
   Exclude:

.ruby-version

@@ -0,0 +1 @@
+3.4.1

CONTRIBUTING.md

@@ -26,3 +26,11 @@
 * 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
+
+## Releasing
+
+* Bump the version in `lib/liquid/version.rb`
+* Update the `History.md` file
+* Open a PR like [this one](https://github.com/Shopify/liquid/pull/1894) and merge it to `main`
+* Create a new release using the [GitHub UI](https://github.com/Shopify/liquid/releases/new)
+

Gemfile

@@ -7,22 +7,25 @@ end
 
 gemspec
 
+gem "base64"
+
 group :benchmark, :test do
   gem 'benchmark-ips'
   gem 'memory_profiler'
   gem 'terminal-table'
+  gem "lru_redux"
 
   install_if -> { RUBY_PLATFORM !~ /mingw|mswin|java/ && RUBY_ENGINE != 'truffleruby' } do
     gem 'stackprof'
   end
 end
 
+group :development do
+  gem "webrick"
+end
+
 group :test do
-  gem 'rubocop', '~> 1.44.0'
+  gem 'rubocop', '~> 1.61.0'
   gem 'rubocop-shopify', '~> 2.12.0', require: false
   gem 'rubocop-performance', require: false
-
-  platform :mri, :truffleruby do
-    gem 'liquid-c', github: 'Shopify/liquid-c', ref: 'master'
-  end
 end

History.md

@@ -1,5 +1,70 @@
 # Liquid Change Log
 
+## 5.7.3 (unreleased)
+
+* Raise Liquid::SyntaxError when parsing invalidly encoded strings
+
+## 5.7.2 2025-01-31
+
+* Fix array filters to not support nested properties
+
+## 5.7.1 2025-01-24
+
+* Fix the `find` and `find_index`filters to return `nil` when filtering empty arrays
+* Fix the `has` filter to return `false` when filtering empty arrays
+
+## 5.7.0 2025-01-16
+
+### Features
+
+* Add `find`, `find_index`, `has`, and `reject` filters to arrays
+* Compatibility with Ruby 3.4
+
+## 5.6.4 2025-01-14
+
+### Fixes
+* Add a default `string_scanner` to avoid errors with `Liquid::VariableLookup.parse("foo.bar")` [Ian Ker-Seymer]
+
+## 5.6.3 2025-01-13
+* Remove `lru_redux` dependency [Michael Go]
+
+## 5.6.2 2025-01-13
+
+### Fixes
+* Preserve the old behavior of requiring floats to start with a digit [Michael Go]
+
+## 5.6.1 2025-01-13
+
+### Performance improvements
+* Faster Expression parser / Tokenizer with StringScanner [Michael Go]
+
+## 5.6.0 2024-12-19
+
+### Architectural changes
+* Added new `Environment` class to manage configuration and state that was previously stored in `Template` [Ian Ker-Seymer]
+* Moved tag registration from `Template` to `Environment` [Ian Ker-Seymer]
+* Removed `StrainerFactory` in favor of `Environment`-based strainer creation [Ian Ker-Seymer]
+* Consolidated standard tags into a new `Tags` module with `STANDARD_TAGS` constant [Ian Ker-Seymer]
+
+### Performance improvements
+* Optimized `Lexer` with a new `Lexer2` implementation using jump tables for faster tokenization, requires Ruby 3.4 [Ian Ker-Seymer]
+* Improved variable rendering with specialized handling for different types [Michael Go]
+* Reduced array allocations by using frozen empty constants [Michael Go]
+
+### API changes
+* Deprecated several `Template` class methods in favor of `Environment` methods [Ian Ker-Seymer]
+* Added deprecation warnings system [Ian Ker-Seymer]
+* Changed how filters and tags are registered to use Environment [Ian Ker-Seymer]
+
+### Fixes
+* Fixed table row handling of break interrupts [Alex Coco]
+* Improved variable output handling for arrays [Ian Ker-Seymer]
+* Fix Tokenizer to handle null source value (#1873) [Bahar Pourazar]
+
+## 5.5.0 2024-03-21
+
+Please reference the GitHub release for more information.
+
 ## 5.4.0 2022-07-29
 
 ### Breaking Changes

README.md

@@ -1,4 +1,4 @@
-[![Build Status](https://api.travis-ci.org/Shopify/liquid.svg?branch=master)](http://travis-ci.org/Shopify/liquid)
+[![Build status](https://github.com/Shopify/liquid/actions/workflows/liquid.yml/badge.svg)](https://github.com/Shopify/liquid/actions/workflows/liquid.yml)
 [![Inline docs](http://inch-ci.org/github/Shopify/liquid.svg?branch=master)](http://inch-ci.org/github/Shopify/liquid)
 
 # Liquid template engine
@@ -52,6 +52,47 @@ For standard use you can just pass it the content of a file and call render with
 @template.render('name' => 'tobi')                # => "hi tobi"
 ```
 
+### Concept of Environments
+
+In Liquid, a "Environment" is a scoped environment that encapsulates custom tags, filters, and other configurations. This allows you to define and isolate different sets of functionality for different contexts, avoiding global overrides that can lead to conflicts and unexpected behavior.
+
+By using environments, you can:
+
+1. **Encapsulate Logic**: Keep the logic for different parts of your application separate.
+2. **Avoid Conflicts**: Prevent custom tags and filters from clashing with each other.
+3. **Improve Maintainability**: Make it easier to manage and understand the scope of customizations.
+4. **Enhance Security**: Limit the availability of certain tags and filters to specific contexts.
+
+We encourage the use of Environments over globally overriding things because it promotes better software design principles such as modularity, encapsulation, and separation of concerns.
+
+Here's an example of how you can define and use Environments in Liquid:
+
+```ruby
+user_environment = Liquid::Environment.build do |environment|
+  environment.register_tag("renderobj", RenderObjTag)
+end
+
+Liquid::Template.parse(<<~LIQUID, environment: user_environment)
+  {% renderobj src: "path/to/model.obj" %}
+LIQUID
+```
+
+In this example, `RenderObjTag` is a custom tag that is only available within the `user_environment`.
+
+Similarly, you can define another environment for a different context, such as email templates:
+
+```ruby
+email_environment = Liquid::Environment.build do |environment|
+  environment.register_tag("unsubscribe_footer", UnsubscribeFooter)
+end
+
+Liquid::Template.parse(<<~LIQUID, environment: email_environment)
+  {% unsubscribe_footer %}
+LIQUID
+```
+
+By using Environments, you ensure that custom tags and filters are only available in the contexts where they are needed, making your Liquid templates more robust and easier to manage. For smaller projects, a global environment is available via `Liquid::Environment.default`.
+
 ### Error Modes
 
 Setting the error mode of Liquid lets you specify how strictly you want your templates to be interpreted.
@@ -62,9 +103,10 @@ Liquid also comes with a stricter parser that can be used when editing templates
 when templates are invalid. You can enable this new parser like this:
 
 ```ruby
-Liquid::Template.error_mode = :strict # Raises a SyntaxError when invalid syntax is used
+Liquid::Environment.default.error_mode = :strict
-Liquid::Template.error_mode = :warn # Adds strict errors to template.errors but continues as normal
+Liquid::Environment.default.error_mode = :strict # Raises a SyntaxError when invalid syntax is used
-Liquid::Template.error_mode = :lax # The default mode, accepts almost anything.
+Liquid::Environment.default.error_mode = :warn # Adds strict errors to template.errors but continues as normal
+Liquid::Environment.default.error_mode = :lax # The default mode, accepts almost anything.
 ```
 
 If you want to set the error mode only on specific templates you can pass `:error_mode` as an option to `parse`:

Rakefile

@@ -43,8 +43,6 @@ task :test do
   Rake::Task['base_test'].invoke
 
   if RUBY_ENGINE == 'ruby' || RUBY_ENGINE == 'truffleruby'
-    ENV['LIQUID_C'] = '1'
-
     ENV['LIQUID_PARSER_MODE'] = 'lax'
     Rake::Task['integration_test'].reenable
     Rake::Task['integration_test'].invoke
@@ -73,7 +71,7 @@ end
 
 namespace :benchmark do
   desc "Run the liquid benchmark with lax parsing"
-  task :run do
+  task :lax do
     ruby "./performance/benchmark.rb lax"
   end
 
@@ -81,6 +79,33 @@ namespace :benchmark do
   task :strict do
     ruby "./performance/benchmark.rb strict"
   end
+
+  desc "Run the liquid benchmark with both lax and strict parsing"
+  task run: [:lax, :strict]
+
+  desc "Run unit benchmarks"
+  namespace :unit do
+    task :all do
+      Dir["./performance/unit/*_benchmark.rb"].each do |file|
+        puts "🧪 Running #{file}"
+        ruby file
+      end
+    end
+
+    task :lexer do
+      Dir["./performance/unit/lexer_benchmark.rb"].each do |file|
+        puts "🧪 Running #{file}"
+        ruby file
+      end
+    end
+
+    task :expression do
+      Dir["./performance/unit/expression_benchmark.rb"].each do |file|
+        puts "🧪 Running #{file}"
+        ruby file
+      end
+    end
+  end
 end
 
 namespace :profile do

lib/liquid.rb

@@ -21,6 +21,8 @@
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
+require "strscan"
+
 module Liquid
   FilterSeparator             = /\|/
   ArgumentSeparator           = ','
@@ -44,13 +46,21 @@ module Liquid
   VariableParser              = /\[(?>[^\[\]]+|\g<0>)*\]|#{VariableSegment}+\??/o
 
   RAISE_EXCEPTION_LAMBDA = ->(_e) { raise }
-
+  HAS_STRING_SCANNER_SCAN_BYTE = StringScanner.instance_methods.include?(:scan_byte)
-  singleton_class.send(:attr_accessor, :cache_classes)
-  self.cache_classes = true
 end
 
 require "liquid/version"
+require "liquid/deprecations"
+require "liquid/const"
+require 'liquid/standardfilters'
+require 'liquid/file_system'
+require 'liquid/parser_switching'
+require 'liquid/tag'
+require 'liquid/block'
 require 'liquid/parse_tree_visitor'
+require 'liquid/interrupts'
+require 'liquid/tags'
+require "liquid/environment"
 require 'liquid/lexer'
 require 'liquid/parser'
 require 'liquid/i18n'
@@ -61,23 +71,16 @@ require 'liquid/extensions'
 require 'liquid/errors'
 require 'liquid/interrupts'
 require 'liquid/strainer_template'
-require 'liquid/strainer_factory'
-require 'liquid/expression'
 require 'liquid/context'
-require 'liquid/parser_switching'
 require 'liquid/tag'
-require 'liquid/tag/disabler'
-require 'liquid/tag/disableable'
-require 'liquid/block'
 require 'liquid/block_body'
 require 'liquid/document'
 require 'liquid/variable'
 require 'liquid/variable_lookup'
 require 'liquid/range_lookup'
-require 'liquid/file_system'
 require 'liquid/resource_limits'
+require 'liquid/expression'
 require 'liquid/template'
-require 'liquid/standardfilters'
 require 'liquid/condition'
 require 'liquid/utils'
 require 'liquid/tokenizer'
@@ -86,7 +89,3 @@ require 'liquid/partial_cache'
 require 'liquid/usage'
 require 'liquid/registers'
 require 'liquid/template_factory'
-
-# Load all the tags of the standard library
-#
-Dir["#{__dir__}/liquid/tags/*.rb"].each { |f| require f }

lib/liquid/block_body.rb

@@ -6,6 +6,7 @@ module Liquid
   class BlockBody
     LiquidTagToken      = /\A\s*(#{TagName})\s*(.*?)\z/o
     FullToken           = /\A#{TagStart}#{WhitespaceControl}?(\s*)(#{TagName})(\s*)(.*?)#{WhitespaceControl}?#{TagEnd}\z/om
+    FullTokenPossiblyInvalid = /\A(.*)#{TagStart}#{WhitespaceControl}?\s*(\w+)\s*(.*)?#{WhitespaceControl}?#{TagEnd}\z/om
     ContentOfVariable   = /\A#{VariableStart}#{WhitespaceControl}?(.*?)#{WhitespaceControl}?#{VariableEnd}\z/om
     WhitespaceOrNothing = /\A\s*\z/
     TAGSTART            = "{%"
@@ -51,7 +52,7 @@ module Liquid
             next parse_liquid_tag(markup, parse_context)
           end
 
-          unless (tag = registered_tags[tag_name])
+          unless (tag = parse_context.environment.tag_for_name(tag_name))
             # end parsing if we reach an unknown tag and let the caller decide
             # determine how to proceed
             return yield tag_name, markup
@@ -146,7 +147,7 @@ module Liquid
             next
           end
 
-          unless (tag = registered_tags[tag_name])
+          unless (tag = parse_context.environment.tag_for_name(tag_name))
             # end parsing if we reach an unknown tag and let the caller decide
             # determine how to proceed
             return yield tag_name, markup
@@ -245,10 +246,17 @@ module Liquid
     end
 
     def create_variable(token, parse_context)
-      if token =~ ContentOfVariable
+      if token.end_with?("}}")
-        markup = Regexp.last_match(1)
+        i = 2
+        i = 3 if token[i] == "-"
+        parse_end = token.length - 3
+        parse_end -= 1 if token[parse_end] == "-"
+        markup_end = parse_end - i + 1
+        markup = markup_end <= 0 ? "" : token.slice(i, markup_end)
+
         return Variable.new(markup, parse_context)
       end
+
       BlockBody.raise_missing_variable_terminator(token, parse_context)
     end
 
@@ -261,9 +269,5 @@ module Liquid
     def raise_missing_variable_terminator(token, parse_context)
       BlockBody.raise_missing_variable_terminator(token, parse_context)
     end
-
-    def registered_tags
-      Template.tags
-    end
   end
 end

lib/liquid/condition.rb

@@ -24,6 +24,9 @@ module Liquid
         else
           false
         end
+      rescue Encoding::CompatibilityError
+        # "✅".b.include?("✅") raises Encoding::CompatibilityError despite being materially equal
+        left.b.include?(right.b)
       end,
     }
 

lib/liquid/const.rb

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+module Liquid
+  module Const
+    EMPTY_HASH = {}.freeze
+    EMPTY_ARRAY = [].freeze
+  end
+end

lib/liquid/context.rb

@@ -15,35 +15,40 @@ module Liquid
   #   context['bob']  #=> nil  class Context
   class Context
     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
+    attr_accessor :exception_renderer, :template_name, :partial, :global_filter, :strict_variables, :strict_filters, :environment
 
     # rubocop:disable Metrics/ParameterLists
-    def self.build(environments: {}, outer_scope: {}, registers: {}, rethrow_errors: false, resource_limits: nil, static_environments: {}, &block)
+    def self.build(environment: Environment.default, 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)
+      new(environments, outer_scope, registers, rethrow_errors, resource_limits, static_environments, environment, &block)
     end
 
-    def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil, static_environments = {})
+    def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil, static_environments = {}, environment = Environment.default)
+      @environment = environment
       @environments = [environments]
       @environments.flatten!
 
       @static_environments = [static_environments].flatten(1).freeze
-      @scopes              = [(outer_scope || {})]
+      @scopes              = [outer_scope || {}]
       @registers           = registers.is_a?(Registers) ? registers : Registers.new(registers)
       @errors              = []
       @partial             = false
       @strict_variables    = false
-      @resource_limits     = resource_limits || ResourceLimits.new(Template.default_resource_limits)
+      @resource_limits     = resource_limits || ResourceLimits.new(environment.default_resource_limits)
       @base_scope_depth    = 0
       @interrupts          = []
       @filters             = []
       @global_filter       = nil
       @disabled_tags       = {}
 
+      # Instead of constructing new StringScanner objects for each Expression parse,
+      # we recycle the same one.
+      @string_scanner = StringScanner.new("")
+
       @registers.static[:cached_partials] ||= {}
-      @registers.static[:file_system] ||= Liquid::Template.file_system
+      @registers.static[:file_system] ||= environment.file_system
       @registers.static[:template_factory] ||= Liquid::TemplateFactory.new
 
-      self.exception_renderer = Template.default_exception_renderer
+      self.exception_renderer = environment.exception_renderer
       if rethrow_errors
         self.exception_renderer = Liquid::RAISE_EXCEPTION_LAMBDA
       end
@@ -60,7 +65,7 @@ module Liquid
     end
 
     def strainer
-      @strainer ||= StrainerFactory.create(self, @filters)
+      @strainer ||= @environment.create_strainer(self, @filters)
     end
 
     # Adds filters to this context.
@@ -142,6 +147,7 @@ module Liquid
       check_overflow
 
       self.class.build(
+        environment: @environment,
         resource_limits: resource_limits,
         static_environments: static_environments,
         registers: Registers.new(registers),
@@ -174,7 +180,7 @@ module Liquid
     # Example:
     #   products == empty #=> products.empty?
     def [](expression)
-      evaluate(Expression.parse(expression))
+      evaluate(Expression.parse(expression, @string_scanner))
     end
 
     def key?(key)
@@ -197,10 +203,14 @@ module Liquid
         try_variable_find_in_environments(key, raise_on_not_found: raise_on_not_found)
       end
 
-      variable         = variable.to_liquid
+      # update variable's context before invoking #to_liquid
       variable.context = self if variable.respond_to?(:context=)
 
-      variable
+      liquid_variable = variable.to_liquid
+
+      liquid_variable.context = self if variable != liquid_variable && liquid_variable.respond_to?(:context=)
+
+      liquid_variable
     end
 
     def lookup_and_evaluate(obj, key, raise_on_not_found: true)

lib/liquid/deprecations.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+require "set"
+
+module Liquid
+  class Deprecations
+    class << self
+      attr_accessor :warned
+
+      Deprecations.warned = Set.new
+
+      def warn(name, alternative)
+        return if warned.include?(name)
+
+        warned << name
+
+        caller_location = caller_locations(2, 1).first
+        Warning.warn("[DEPRECATION] #{name} is deprecated. Use #{alternative} instead. Called from #{caller_location}\n")
+      end
+    end
+  end
+end

lib/liquid/environment.rb

@@ -0,0 +1,159 @@
+# frozen_string_literal: true
+
+module Liquid
+  # The Environment is the container for all configuration options of Liquid, such as
+  # the registered tags, filters, and the default error mode.
+  class Environment
+    # The default error mode for all templates. This can be overridden on a
+    # per-template basis.
+    attr_accessor :error_mode
+
+    # The tags that are available to use in the template.
+    attr_accessor :tags
+
+    # The strainer template which is used to store filters that are available to
+    # use in templates.
+    attr_accessor :strainer_template
+
+    # The exception renderer that is used to render exceptions that are raised
+    # when rendering a template
+    attr_accessor :exception_renderer
+
+    # The default file system that is used to load templates from.
+    attr_accessor :file_system
+
+    # The default resource limits that are used to limit the resources that a
+    # template can consume.
+    attr_accessor :default_resource_limits
+
+    class << self
+      # Creates a new environment instance.
+      #
+      # @param tags [Hash] The tags that are available to use in
+      #  the template.
+      # @param file_system The default file system that is used
+      #  to load templates from.
+      # @param error_mode [Symbol] The default error mode for all templates
+      #  (either :strict, :warn, or :lax).
+      # @param exception_renderer [Proc] The exception renderer that is used to
+      #   render exceptions.
+      # @yieldparam environment [Environment] The environment instance that is being built.
+      # @return [Environment] The new environment instance.
+      def build(tags: nil, file_system: nil, error_mode: nil, exception_renderer: nil)
+        ret = new
+        ret.tags = tags if tags
+        ret.file_system = file_system if file_system
+        ret.error_mode = error_mode if error_mode
+        ret.exception_renderer = exception_renderer if exception_renderer
+        yield ret if block_given?
+        ret.freeze
+      end
+
+      # Returns the default environment instance.
+      #
+      # @return [Environment] The default environment instance.
+      def default
+        @default ||= new
+      end
+
+      # Sets the default environment instance for the duration of the block
+      #
+      # @param environment [Environment] The environment instance to use as the default for the
+      #   duration of the block.
+      # @yield
+      # @return [Object] The return value of the block.
+      def dangerously_override(environment)
+        original_default = @default
+        @default = environment
+        yield
+      ensure
+        @default = original_default
+      end
+    end
+
+    # Initializes a new environment instance.
+    # @api private
+    def initialize
+      @tags = Tags::STANDARD_TAGS.dup
+      @error_mode = :lax
+      @strainer_template = Class.new(StrainerTemplate).tap do |klass|
+        klass.add_filter(StandardFilters)
+      end
+      @exception_renderer = ->(exception) { exception }
+      @file_system = BlankFileSystem.new
+      @default_resource_limits = Const::EMPTY_HASH
+      @strainer_template_class_cache = {}
+    end
+
+    # Registers a new tag with the environment.
+    #
+    # @param name [String] The name of the tag.
+    # @param klass [Liquid::Tag] The class that implements the tag.
+    # @return [void]
+    def register_tag(name, klass)
+      @tags[name] = klass
+    end
+
+    # Registers a new filter with the environment.
+    #
+    # @param filter [Module] The module that contains the filter methods.
+    # @return [void]
+    def register_filter(filter)
+      @strainer_template_class_cache.clear
+      @strainer_template.add_filter(filter)
+    end
+
+    # Registers multiple filters with this environment.
+    #
+    # @param filters [Array<Module>] The modules that contain the filter methods.
+    # @return [self]
+    def register_filters(filters)
+      @strainer_template_class_cache.clear
+      filters.each { |f| @strainer_template.add_filter(f) }
+      self
+    end
+
+    # Creates a new strainer instance with the given filters, caching the result
+    # for faster lookup.
+    #
+    # @param context [Liquid::Context] The context that the strainer will be
+    #   used in.
+    # @param filters [Array<Module>] The filters that the strainer will have
+    #   access to.
+    # @return [Liquid::Strainer] The new strainer instance.
+    def create_strainer(context, filters = Const::EMPTY_ARRAY)
+      return @strainer_template.new(context) if filters.empty?
+
+      strainer_template = @strainer_template_class_cache[filters] ||= begin
+        klass = Class.new(@strainer_template)
+        filters.each { |f| klass.add_filter(f) }
+        klass
+      end
+
+      strainer_template.new(context)
+    end
+
+    # Returns the names of all the filter methods that are available to use in
+    # the strainer template.
+    #
+    # @return [Array<String>] The names of all the filter methods.
+    def filter_method_names
+      @strainer_template.filter_method_names
+    end
+
+    # Returns the tag class for the given tag name.
+    #
+    # @param name [String] The name of the tag.
+    # @return [Liquid::Tag] The tag class.
+    def tag_for_name(name)
+      @tags[name]
+    end
+
+    def freeze
+      @tags.freeze
+      # TODO: freeze the tags, currently this is not possible because of liquid-c
+      # @strainer_template.freeze
+      super
+    end
+  end
+end

lib/liquid/errors.rb

@@ -40,19 +40,20 @@ module Liquid
     end
   end
 
-  ArgumentError       = Class.new(Error)
+  ArgumentError         = Class.new(Error)
-  ContextError        = Class.new(Error)
+  ContextError          = Class.new(Error)
-  FileSystemError     = Class.new(Error)
+  FileSystemError       = Class.new(Error)
-  StandardError       = Class.new(Error)
+  StandardError         = Class.new(Error)
-  SyntaxError         = Class.new(Error)
+  SyntaxError           = Class.new(Error)
-  StackLevelError     = Class.new(Error)
+  StackLevelError       = Class.new(Error)
-  MemoryError         = Class.new(Error)
+  MemoryError           = Class.new(Error)
-  ZeroDivisionError   = Class.new(Error)
+  ZeroDivisionError     = Class.new(Error)
-  FloatDomainError    = Class.new(Error)
+  FloatDomainError      = Class.new(Error)
-  UndefinedVariable   = Class.new(Error)
+  UndefinedVariable     = Class.new(Error)
-  UndefinedDropMethod = Class.new(Error)
+  UndefinedDropMethod   = Class.new(Error)
-  UndefinedFilter     = Class.new(Error)
+  UndefinedFilter       = Class.new(Error)
-  MethodOverrideError = Class.new(Error)
+  MethodOverrideError   = Class.new(Error)
-  DisabledError       = Class.new(Error)
+  DisabledError         = Class.new(Error)
-  InternalError       = Class.new(Error)
+  InternalError         = Class.new(Error)
+  TemplateEncodingError = Class.new(Error)
 end

lib/liquid/expression.rb

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

lib/liquid/lexer.rb

@@ -1,61 +1,179 @@
 # frozen_string_literal: true
 
-require "strscan"
 module Liquid
   class Lexer
-    SPECIALS = {
+    CLOSE_ROUND = [:close_round, ")"].freeze
-      '|' => :pipe,
+    CLOSE_SQUARE = [:close_square, "]"].freeze
-      '.' => :dot,
+    COLON = [:colon, ":"].freeze
-      ':' => :colon,
+    COMMA = [:comma, ","].freeze
-      ',' => :comma,
+    COMPARISION_NOT_EQUAL = [:comparison, "!="].freeze
-      '[' => :open_square,
+    COMPARISON_CONTAINS = [:comparison, "contains"].freeze
-      ']' => :close_square,
+    COMPARISON_EQUAL = [:comparison, "=="].freeze
-      '(' => :open_round,
+    COMPARISON_GREATER_THAN = [:comparison, ">"].freeze
-      ')' => :close_round,
+    COMPARISON_GREATER_THAN_OR_EQUAL = [:comparison, ">="].freeze
-      '?' => :question,
+    COMPARISON_LESS_THAN = [:comparison, "<"].freeze
-      '-' => :dash,
+    COMPARISON_LESS_THAN_OR_EQUAL = [:comparison, "<="].freeze
-    }.freeze
+    COMPARISON_NOT_EQUAL_ALT = [:comparison, "<>"].freeze
-    IDENTIFIER            = /[a-zA-Z_][\w-]*\??/
+    DASH = [:dash, "-"].freeze
-    SINGLE_STRING_LITERAL = /'[^\']*'/
+    DOT = [:dot, "."].freeze
+    DOTDOT = [:dotdot, ".."].freeze
+    DOT_ORD = ".".ord
     DOUBLE_STRING_LITERAL = /"[^\"]*"/
-    STRING_LITERAL        = Regexp.union(SINGLE_STRING_LITERAL, DOUBLE_STRING_LITERAL)
+    EOS = [:end_of_string].freeze
+    IDENTIFIER            = /[a-zA-Z_][\w-]*\??/
     NUMBER_LITERAL        = /-?\d+(\.\d+)?/
-    DOTDOT                = /\.\./
+    OPEN_ROUND = [:open_round, "("].freeze
-    COMPARISON_OPERATOR   = /==|!=|<>|<=?|>=?|contains(?=\s)/
+    OPEN_SQUARE = [:open_square, "["].freeze
+    PIPE = [:pipe, "|"].freeze
+    QUESTION = [:question, "?"].freeze
+    RUBY_WHITESPACE = [" ", "\t", "\r", "\n", "\f"].freeze
+    SINGLE_STRING_LITERAL = /'[^\']*'/
     WHITESPACE_OR_NOTHING = /\s*/
 
-    def initialize(input)
+    SINGLE_COMPARISON_TOKENS = [].tap do |table|
-      @ss = StringScanner.new(input)
+      table["<".ord] = COMPARISON_LESS_THAN
+      table[">".ord] = COMPARISON_GREATER_THAN
+      table.freeze
     end
 
-    def tokenize
+    TWO_CHARS_COMPARISON_JUMP_TABLE = [].tap do |table|
-      @output = []
+      table["=".ord] = [].tap do |sub_table|
+        sub_table["=".ord] = COMPARISON_EQUAL
+        sub_table.freeze
+      end
+      table["!".ord] = [].tap do |sub_table|
+        sub_table["=".ord] = COMPARISION_NOT_EQUAL
+        sub_table.freeze
+      end
+      table.freeze
+    end
 
-      until @ss.eos?
+    COMPARISON_JUMP_TABLE = [].tap do |table|
-        @ss.skip(WHITESPACE_OR_NOTHING)
+      table["<".ord] = [].tap do |sub_table|
-        break if @ss.eos?
+        sub_table["=".ord] = COMPARISON_LESS_THAN_OR_EQUAL
-        tok      = if (t = @ss.scan(COMPARISON_OPERATOR))
+        sub_table[">".ord] = COMPARISON_NOT_EQUAL_ALT
-          [:comparison, t]
+        sub_table.freeze
-        elsif (t = @ss.scan(STRING_LITERAL))
+      end
-          [:string, t]
+      table[">".ord] = [].tap do |sub_table|
-        elsif (t = @ss.scan(NUMBER_LITERAL))
+        sub_table["=".ord] = COMPARISON_GREATER_THAN_OR_EQUAL
-          [:number, t]
+        sub_table.freeze
-        elsif (t = @ss.scan(IDENTIFIER))
+      end
-          [:id, t]
+      table.freeze
-        elsif (t = @ss.scan(DOTDOT))
+    end
-          [:dotdot, t]
+
-        else
+    NEXT_MATCHER_JUMP_TABLE = [].tap do |table|
-          c     = @ss.getch
+      "a".upto("z") do |c|
-          if (s = SPECIALS[c])
+        table[c.ord] = [:id, IDENTIFIER].freeze
-            [s, c]
+        table[c.upcase.ord] = [:id, IDENTIFIER].freeze
+      end
+      table["_".ord] = [:id, IDENTIFIER].freeze
+
+      "0".upto("9") do |c|
+        table[c.ord] = [:number, NUMBER_LITERAL].freeze
+      end
+      table["-".ord] = [:number, NUMBER_LITERAL].freeze
+
+      table["'".ord] = [:string, SINGLE_STRING_LITERAL].freeze
+      table["\"".ord] = [:string, DOUBLE_STRING_LITERAL].freeze
+      table.freeze
+    end
+
+    SPECIAL_TABLE = [].tap do |table|
+      table["|".ord] = PIPE
+      table[".".ord] = DOT
+      table[":".ord] = COLON
+      table[",".ord] = COMMA
+      table["[".ord] = OPEN_SQUARE
+      table["]".ord] = CLOSE_SQUARE
+      table["(".ord] = OPEN_ROUND
+      table[")".ord] = CLOSE_ROUND
+      table["?".ord] = QUESTION
+      table["-".ord] = DASH
+    end
+
+    NUMBER_TABLE = [].tap do |table|
+      "0".upto("9") do |c|
+        table[c.ord] = true
+      end
+      table.freeze
+    end
+
+    # rubocop:disable Metrics/BlockNesting
+    class << self
+      def tokenize(ss)
+        output = []
+
+        until ss.eos?
+          ss.skip(WHITESPACE_OR_NOTHING)
+
+          break if ss.eos?
+
+          start_pos = ss.pos
+          peeked = ss.peek_byte
+
+          if (special = SPECIAL_TABLE[peeked])
+            ss.scan_byte
+            # Special case for ".."
+            if special == DOT && ss.peek_byte == DOT_ORD
+              ss.scan_byte
+              output << DOTDOT
+            elsif special == DASH
+              # Special case for negative numbers
+              if (peeked_byte = ss.peek_byte) && NUMBER_TABLE[peeked_byte]
+                ss.pos -= 1
+                output << [:number, ss.scan(NUMBER_LITERAL)]
+              else
+                output << special
+              end
+            else
+              output << special
+            end
+          elsif (sub_table = TWO_CHARS_COMPARISON_JUMP_TABLE[peeked])
+            ss.scan_byte
+            if (peeked_byte = ss.peek_byte) && (found = sub_table[peeked_byte])
+              output << found
+              ss.scan_byte
+            else
+              raise_syntax_error(start_pos, ss)
+            end
+          elsif (sub_table = COMPARISON_JUMP_TABLE[peeked])
+            ss.scan_byte
+            if (peeked_byte = ss.peek_byte) && (found = sub_table[peeked_byte])
+              output << found
+              ss.scan_byte
+            else
+              output << SINGLE_COMPARISON_TOKENS[peeked]
+            end
           else
-            raise SyntaxError, "Unexpected character #{c}"
+            type, pattern = NEXT_MATCHER_JUMP_TABLE[peeked]
+
+            if type && (t = ss.scan(pattern))
+              # Special case for "contains"
+              output << if type == :id && t == "contains" && output.last&.first != :dot
+                COMPARISON_CONTAINS
+              else
+                [type, t]
+              end
+            else
+              raise_syntax_error(start_pos, ss)
+            end
           end
         end
-        @output << tok
+        # rubocop:enable Metrics/BlockNesting
+        output << EOS
+      rescue ::ArgumentError => e
+        if e.message == "invalid byte sequence in #{ss.string.encoding}"
+          raise SyntaxError, "Invalid byte sequence in #{ss.string.encoding}"
+        else
+          raise
+        end
       end
 
-      @output << [:end_of_string]
+      def raise_syntax_error(start_pos, ss)
+        ss.pos = start_pos
+        # the character could be a UTF-8 character, use getch to get all the bytes
+        raise SyntaxError, "Unexpected character #{ss.getch}"
+      end
     end
   end
 end

lib/liquid/locales/en.yml

@@ -15,6 +15,7 @@
       include: "Error in tag 'include' - Valid syntax: include '[template]' (with|for) [object|collection]"
       inline_comment_invalid: "Syntax error in tag '#' - Each line of comments must be prefixed by the '#' character"
       invalid_delimiter: "'%{tag}' is not a valid delimiter for %{block_name} tags. use %{block_delimiter}"
+      invalid_template_encoding: "Invalid template encoding"
       render: "Syntax error in tag 'render' - Template name must be a quoted string"
       table_row: "Syntax Error in 'table_row loop' - Valid syntax: table_row [item] in [collection] cols=3"
       tag_never_closed: "'%{block_name}' tag was never closed"

lib/liquid/parse_context.rb

@@ -3,14 +3,27 @@
 module Liquid
   class ParseContext
     attr_accessor :locale, :line_number, :trim_whitespace, :depth
-    attr_reader :partial, :warnings, :error_mode
+    attr_reader :partial, :warnings, :error_mode, :environment
 
-    def initialize(options = {})
+    def initialize(options = Const::EMPTY_HASH)
+      @environment = options.fetch(:environment, Environment.default)
       @template_options = options ? options.dup : {}
 
       @locale   = @template_options[:locale] ||= I18n.new
       @warnings = []
 
+      # constructing new StringScanner in Lexer, Tokenizer, etc is expensive
+      # This StringScanner will be shared by all of them
+      @string_scanner = StringScanner.new("")
+
+      @expression_cache = if options[:expression_cache].nil?
+        {}
+      elsif options[:expression_cache].respond_to?(:[]) && options[:expression_cache].respond_to?(:[]=)
+        options[:expression_cache]
+      elsif options[:expression_cache]
+        {}
+      end
+
       self.depth   = 0
       self.partial = false
     end
@@ -23,19 +36,29 @@ module Liquid
       Liquid::BlockBody.new
     end
 
-    def new_tokenizer(markup, start_line_number: nil, for_liquid_tag: false)
+    def new_parser(input)
-      Tokenizer.new(markup, line_number: start_line_number, for_liquid_tag: for_liquid_tag)
+      @string_scanner.string = input
+      Parser.new(@string_scanner)
+    end
+
+    def new_tokenizer(source, start_line_number: nil, for_liquid_tag: false)
+      Tokenizer.new(
+        source: source,
+        string_scanner: @string_scanner,
+        line_number: start_line_number,
+        for_liquid_tag: for_liquid_tag,
+      )
     end
 
     def parse_expression(markup)
-      Expression.parse(markup)
+      Expression.parse(markup, @string_scanner, @expression_cache)
     end
 
     def partial=(value)
       @partial = value
       @options = value ? partial_options : @template_options
 
-      @error_mode = @options[:error_mode] || Template.error_mode
+      @error_mode = @options[:error_mode] || @environment.error_mode
     end
 
     def partial_options

lib/liquid/parse_tree_visitor.rb

@@ -36,7 +36,7 @@ module Liquid
     protected
 
     def children
-      @node.respond_to?(:nodelist) ? Array(@node.nodelist) : []
+      @node.respond_to?(:nodelist) ? Array(@node.nodelist) : Const::EMPTY_ARRAY
     end
   end
 end

lib/liquid/parser.rb

@@ -3,8 +3,8 @@
 module Liquid
   class Parser
     def initialize(input)
-      l       = Lexer.new(input)
+      ss = input.is_a?(StringScanner) ? input : StringScanner.new(input)
-      @tokens = l.tokenize
+      @tokens = Lexer.tokenize(ss)
       @p      = 0 # pointer to current location
     end
 
@@ -53,7 +53,7 @@ module Liquid
         str = consume
         str << variable_lookups
       when :open_square
-        str = consume
+        str = consume.dup
         str << expression
         str << consume(:close_square)
         str << variable_lookups

lib/liquid/range_lookup.rb

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

lib/liquid/standardfilters.rb

@@ -29,6 +29,19 @@ module Liquid
     )
     STRIP_HTML_TAGS = /<.*?>/m
 
+    class << self
+      def try_coerce_encoding(input, encoding:)
+        original_encoding = input.encoding
+        if input.encoding != encoding
+          input.force_encoding(encoding)
+          unless input.valid_encoding?
+            input.force_encoding(original_encoding)
+          end
+        end
+        input
+      end
+    end
+
     # @liquid_public_docs
     # @liquid_type filter
     # @liquid_category array
@@ -51,7 +64,7 @@ module Liquid
     # @liquid_syntax string | downcase
     # @liquid_return [string]
     def downcase(input)
-      input.to_s.downcase
+      Utils.to_s(input).downcase
     end
 
     # @liquid_public_docs
@@ -62,7 +75,7 @@ module Liquid
     # @liquid_syntax string | upcase
     # @liquid_return [string]
     def upcase(input)
-      input.to_s.upcase
+      Utils.to_s(input).upcase
     end
 
     # @liquid_public_docs
@@ -73,7 +86,7 @@ module Liquid
     # @liquid_syntax string | capitalize
     # @liquid_return [string]
     def capitalize(input)
-      input.to_s.capitalize
+      Utils.to_s(input).capitalize
     end
 
     # @liquid_public_docs
@@ -84,7 +97,7 @@ module Liquid
     # @liquid_syntax string | escape
     # @liquid_return [string]
     def escape(input)
-      CGI.escapeHTML(input.to_s) unless input.nil?
+      CGI.escapeHTML(Utils.to_s(input)) unless input.nil?
     end
     alias_method :h, :escape
 
@@ -96,7 +109,7 @@ module Liquid
     # @liquid_syntax string | escape_once
     # @liquid_return [string]
     def escape_once(input)
-      input.to_s.gsub(HTML_ESCAPE_ONCE_REGEXP, HTML_ESCAPE)
+      Utils.to_s(input).gsub(HTML_ESCAPE_ONCE_REGEXP, HTML_ESCAPE)
     end
 
     # @liquid_public_docs
@@ -111,7 +124,7 @@ module Liquid
     # @liquid_syntax string | url_encode
     # @liquid_return [string]
     def url_encode(input)
-      CGI.escape(input.to_s) unless input.nil?
+      CGI.escape(Utils.to_s(input)) unless input.nil?
     end
 
     # @liquid_public_docs
@@ -125,7 +138,7 @@ module Liquid
     def url_decode(input)
       return if input.nil?
 
-      result = CGI.unescape(input.to_s)
+      result = CGI.unescape(Utils.to_s(input))
       raise Liquid::ArgumentError, "invalid byte sequence in #{result.encoding}" unless result.valid_encoding?
 
       result
@@ -139,7 +152,7 @@ module Liquid
     # @liquid_syntax string | base64_encode
     # @liquid_return [string]
     def base64_encode(input)
-      Base64.strict_encode64(input.to_s)
+      Base64.strict_encode64(Utils.to_s(input))
     end
 
     # @liquid_public_docs
@@ -150,7 +163,8 @@ module Liquid
     # @liquid_syntax string | base64_decode
     # @liquid_return [string]
     def base64_decode(input)
-      Base64.strict_decode64(input.to_s)
+      input = Utils.to_s(input)
+      StandardFilters.try_coerce_encoding(Base64.strict_decode64(input), encoding: input.encoding)
     rescue ::ArgumentError
       raise Liquid::ArgumentError, "invalid base64 provided to base64_decode"
     end
@@ -163,7 +177,7 @@ module Liquid
     # @liquid_syntax string | base64_url_safe_encode
     # @liquid_return [string]
     def base64_url_safe_encode(input)
-      Base64.urlsafe_encode64(input.to_s)
+      Base64.urlsafe_encode64(Utils.to_s(input))
     end
 
     # @liquid_public_docs
@@ -174,7 +188,8 @@ module Liquid
     # @liquid_syntax string | base64_url_safe_decode
     # @liquid_return [string]
     def base64_url_safe_decode(input)
-      Base64.urlsafe_decode64(input.to_s)
+      input = Utils.to_s(input)
+      StandardFilters.try_coerce_encoding(Base64.urlsafe_decode64(input), encoding: input.encoding)
     rescue ::ArgumentError
       raise Liquid::ArgumentError, "invalid base64 provided to base64_url_safe_decode"
     end
@@ -197,7 +212,7 @@ module Liquid
         if input.is_a?(Array)
           input.slice(offset, length) || []
         else
-          input.to_s.slice(offset, length) || ''
+          Utils.to_s(input).slice(offset, length) || ''
         end
       rescue RangeError
         if I64_RANGE.cover?(length) && I64_RANGE.cover?(offset)
@@ -221,10 +236,10 @@ module Liquid
     # @liquid_return [string]
     def truncate(input, length = 50, truncate_string = "...")
       return if input.nil?
-      input_str = input.to_s
+      input_str = Utils.to_s(input)
       length    = Utils.to_integer(length)
 
-      truncate_string_str = truncate_string.to_s
+      truncate_string_str = Utils.to_s(truncate_string)
 
       l = length - truncate_string_str.length
       l = 0 if l < 0
@@ -248,7 +263,7 @@ module Liquid
     # @liquid_return [string]
     def truncatewords(input, words = 15, truncate_string = "...")
       return if input.nil?
-      input = input.to_s
+      input = Utils.to_s(input)
       words = Utils.to_integer(words)
       words = 1 if words <= 0
 
@@ -262,7 +277,8 @@ module Liquid
       return input if wordlist.length <= words
 
       wordlist.pop
-      wordlist.join(" ").concat(truncate_string.to_s)
+      truncate_string = Utils.to_s(truncate_string)
+      wordlist.join(" ").concat(truncate_string)
     end
 
     # @liquid_public_docs
@@ -273,7 +289,9 @@ module Liquid
     # @liquid_syntax string | split: string
     # @liquid_return [array[string]]
     def split(input, pattern)
-      input.to_s.split(pattern.to_s)
+      pattern = Utils.to_s(pattern)
+      input = Utils.to_s(input)
+      input.split(pattern)
     end
 
     # @liquid_public_docs
@@ -284,7 +302,8 @@ module Liquid
     # @liquid_syntax string | strip
     # @liquid_return [string]
     def strip(input)
-      input.to_s.strip
+      input = Utils.to_s(input)
+      input.strip
     end
 
     # @liquid_public_docs
@@ -295,7 +314,8 @@ module Liquid
     # @liquid_syntax string | lstrip
     # @liquid_return [string]
     def lstrip(input)
-      input.to_s.lstrip
+      input = Utils.to_s(input)
+      input.lstrip
     end
 
     # @liquid_public_docs
@@ -306,7 +326,8 @@ module Liquid
     # @liquid_syntax string | rstrip
     # @liquid_return [string]
     def rstrip(input)
-      input.to_s.rstrip
+      input = Utils.to_s(input)
+      input.rstrip
     end
 
     # @liquid_public_docs
@@ -317,8 +338,9 @@ module Liquid
     # @liquid_syntax string | strip_html
     # @liquid_return [string]
     def strip_html(input)
+      input = Utils.to_s(input)
       empty  = ''
-      result = input.to_s.gsub(STRIP_HTML_BLOCKS, empty)
+      result = input.gsub(STRIP_HTML_BLOCKS, empty)
       result.gsub!(STRIP_HTML_TAGS, empty)
       result
     end
@@ -331,7 +353,8 @@ module Liquid
     # @liquid_syntax string | strip_newlines
     # @liquid_return [string]
     def strip_newlines(input)
-      input.to_s.gsub(/\r?\n/, '')
+      input = Utils.to_s(input)
+      input.gsub(/\r?\n/, '')
     end
 
     # @liquid_public_docs
@@ -342,6 +365,7 @@ module Liquid
     # @liquid_syntax array | join
     # @liquid_return [string]
     def join(input, glue = ' ')
+      glue = Utils.to_s(glue)
       InputIterator.new(input, context).join(glue)
     end
 
@@ -409,29 +433,59 @@ module Liquid
     # @liquid_syntax array | where: string, string
     # @liquid_return [array[untyped]]
     def where(input, property, target_value = nil)
-      ary = InputIterator.new(input, context)
+      filter_array(input, property, target_value) { |ary, &block| ary.select(&block) }
+    end
 
-      if ary.empty?
+    # @liquid_public_docs
-        []
+    # @liquid_type filter
-      elsif target_value.nil?
+    # @liquid_category array
-        ary.select do |item|
+    # @liquid_summary
-          item[property]
+    #   Filters an array to exclude items with a specific property value.
-        rescue TypeError
+    # @liquid_description
-          raise_property_error(property)
+    #   This requires you to provide both the property name and the associated value.
-        rescue NoMethodError
+    # @liquid_syntax array | reject: string, string
-          return nil unless item.respond_to?(:[])
+    # @liquid_return [array[untyped]]
-          raise
+    def reject(input, property, target_value = nil)
-        end
+      filter_array(input, property, target_value) { |ary, &block| ary.reject(&block) }
-      else
+    end
-        ary.select do |item|
+
-          item[property] == target_value
+    # @liquid_public_docs
-        rescue TypeError
+    # @liquid_type filter
-          raise_property_error(property)
+    # @liquid_category array
-        rescue NoMethodError
+    # @liquid_summary
-          return nil unless item.respond_to?(:[])
+    #   Tests if any item in an array has a specific property value.
-          raise
+    # @liquid_description
-        end
+    #   This requires you to provide both the property name and the associated value.
-      end
+    # @liquid_syntax array | has: string, string
+    # @liquid_return [boolean]
+    def has(input, property, target_value = nil)
+      filter_array(input, property, target_value, false) { |ary, &block| ary.any?(&block) }
+    end
+
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category array
+    # @liquid_summary
+    #   Returns the first item in an array with a specific property value.
+    # @liquid_description
+    #   This requires you to provide both the property name and the associated value.
+    # @liquid_syntax array | find: string, string
+    # @liquid_return [untyped]
+    def find(input, property, target_value = nil)
+      filter_array(input, property, target_value, nil) { |ary, &block| ary.find(&block) }
+    end
+
+    # @liquid_public_docs
+    # @liquid_type filter
+    # @liquid_category array
+    # @liquid_summary
+    #   Returns the index of the first item in an array with a specific property value.
+    # @liquid_description
+    #   This requires you to provide both the property name and the associated value.
+    # @liquid_syntax array | find_index: string, string
+    # @liquid_return [number]
+    def find_index(input, property, target_value = nil)
+      filter_array(input, property, target_value, nil) { |ary, &block| ary.find_index(&block) }
     end
 
     # @liquid_public_docs
@@ -528,7 +582,10 @@ module Liquid
     # @liquid_syntax string | replace: string, string
     # @liquid_return [string]
     def replace(input, string, replacement = '')
-      input.to_s.gsub(string.to_s, replacement.to_s)
+      string = Utils.to_s(string)
+      replacement = Utils.to_s(replacement)
+      input = Utils.to_s(input)
+      input.gsub(string, replacement)
     end
 
     # @liquid_public_docs
@@ -539,7 +596,10 @@ module Liquid
     # @liquid_syntax string | replace_first: string, string
     # @liquid_return [string]
     def replace_first(input, string, replacement = '')
-      input.to_s.sub(string.to_s, replacement.to_s)
+      string = Utils.to_s(string)
+      replacement = Utils.to_s(replacement)
+      input = Utils.to_s(input)
+      input.sub(string, replacement)
     end
 
     # @liquid_public_docs
@@ -550,9 +610,9 @@ module Liquid
     # @liquid_syntax string | replace_last: string, string
     # @liquid_return [string]
     def replace_last(input, string, replacement)
-      input = input.to_s
+      input = Utils.to_s(input)
-      string = string.to_s
+      string = Utils.to_s(string)
-      replacement = replacement.to_s
+      replacement = Utils.to_s(replacement)
 
       start_index = input.rindex(string)
 
@@ -604,7 +664,9 @@ module Liquid
     # @liquid_syntax string | append: string
     # @liquid_return [string]
     def append(input, string)
-      input.to_s + string.to_s
+      input = Utils.to_s(input)
+      string = Utils.to_s(string)
+      input + string
     end
 
     # @liquid_public_docs
@@ -633,7 +695,9 @@ module Liquid
     # @liquid_syntax string | prepend: string
     # @liquid_return [string]
     def prepend(input, string)
-      string.to_s + input.to_s
+      input = Utils.to_s(input)
+      string = Utils.to_s(string)
+      string + input
     end
 
     # @liquid_public_docs
@@ -644,7 +708,8 @@ module Liquid
     # @liquid_syntax string | newline_to_br
     # @liquid_return [string]
     def newline_to_br(input)
-      input.to_s.gsub(/\r?\n/, "<br />\n")
+      input = Utils.to_s(input)
+      input.gsub(/\r?\n/, "<br />\n")
     end
 
     # Reformat a date using Ruby's core Time#strftime( string ) -> string
@@ -679,11 +744,12 @@ module Liquid
     #
     #   See also: http://www.ruby-doc.org/core/Time.html#method-i-strftime
     def date(input, format)
-      return input if format.to_s.empty?
+      str_format = Utils.to_s(format)
+      return input if str_format.empty?
 
       return input unless (date = Utils.to_date(input))
 
-      date.strftime(format.to_s)
+      date.strftime(str_format)
     end
 
     # @liquid_public_docs
@@ -862,7 +928,7 @@ module Liquid
     #   - [`nil`](/docs/api/liquid/basics#nil)
     # @liquid_syntax variable | default: variable
     # @liquid_return [untyped]
-    # @liquid_optional_param allow_false [boolean] Whether to use false values instead of the default.
+    # @liquid_optional_param allow_false: [boolean] Whether to use false values instead of the default.
     def default(input, default_value = '', options = {})
       options = {} unless options.is_a?(Hash)
       false_check = options['allow_false'] ? input.nil? : !Liquid::Utils.to_liquid_value(input)
@@ -892,15 +958,36 @@ module Liquid
         raise_property_error(property)
       end
 
-      InputIterator.new(values_for_sum, context).sum do |item|
+      result = InputIterator.new(values_for_sum, context).sum do |item|
         Utils.to_number(item)
       end
+
+      result.is_a?(BigDecimal) ? result.to_f : result
     end
 
     private
 
     attr_reader :context
 
+    def filter_array(input, property, target_value, default_value = [], &block)
+      ary = InputIterator.new(input, context)
+
+      return default_value if ary.empty?
+
+      block.call(ary) do |item|
+        if target_value.nil?
+          item[property]
+        else
+          item[property] == target_value
+        end
+      rescue TypeError
+        raise_property_error(property)
+      rescue NoMethodError
+        return nil unless item.respond_to?(:[])
+        raise
+      end
+    end
+
     def raise_property_error(property)
       raise Liquid::ArgumentError, "cannot select the property '#{property}'"
     end
@@ -927,6 +1014,8 @@ module Liquid
     def nil_safe_casecmp(a, b)
       if !a.nil? && !b.nil?
         a.to_s.casecmp(b.to_s)
+      elsif a.nil? && b.nil?
+        0
       else
         a.nil? ? 1 : -1
       end
@@ -949,7 +1038,18 @@ module Liquid
       end
 
       def join(glue)
-        to_a.join(glue.to_s)
+        first = true
+        output = +""
+        each do |item|
+          if first
+            first = false
+          else
+            output << glue
+          end
+
+          output << Liquid::Utils.to_s(item)
+        end
+        output
       end
 
       def concat(args)
@@ -982,6 +1082,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_filter(StandardFilters)
 end

lib/liquid/strainer_factory.rb

@@ -1,41 +0,0 @@
-# frozen_string_literal: true
-
-module Liquid
-  # StrainerFactory is the factory for the filters system.
-  module StrainerFactory
-    extend self
-
-    def add_global_filter(filter)
-      strainer_class_cache.clear
-      GlobalCache.add_filter(filter)
-    end
-
-    def create(context, filters = [])
-      strainer_from_cache(filters).new(context)
-    end
-
-    def global_filter_names
-      GlobalCache.filter_method_names
-    end
-
-    GlobalCache = Class.new(StrainerTemplate)
-
-    private
-
-    def strainer_from_cache(filters)
-      if filters.empty?
-        GlobalCache
-      else
-        strainer_class_cache[filters] ||= begin
-          klass = Class.new(GlobalCache)
-          filters.each { |f| klass.add_filter(f) }
-          klass
-        end
-      end
-    end
-
-    def strainer_class_cache
-      @strainer_class_cache ||= {}
-    end
-  end
-end

lib/liquid/tag.rb

@@ -1,5 +1,8 @@
 # frozen_string_literal: true
 
+require 'liquid/tag/disabler'
+require 'liquid/tag/disableable'
+
 module Liquid
   class Tag
     attr_reader :nodelist, :tag_name, :line_number, :parse_context
@@ -54,7 +57,8 @@ module Liquid
     # of the `render_to_output_buffer` method will become the default and the `render`
     # method will be removed.
     def render_to_output_buffer(context, output)
-      output << render(context)
+      render_result = render(context)
+      output << render_result if render_result
       output
     end
 

lib/liquid/tags.rb

@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+require_relative "tags/table_row"
+require_relative "tags/echo"
+require_relative "tags/if"
+require_relative "tags/break"
+require_relative "tags/inline_comment"
+require_relative "tags/for"
+require_relative "tags/assign"
+require_relative "tags/ifchanged"
+require_relative "tags/case"
+require_relative "tags/include"
+require_relative "tags/continue"
+require_relative "tags/capture"
+require_relative "tags/decrement"
+require_relative "tags/unless"
+require_relative "tags/increment"
+require_relative "tags/comment"
+require_relative "tags/raw"
+require_relative "tags/render"
+require_relative "tags/cycle"
+
+module Liquid
+  module Tags
+    STANDARD_TAGS = {
+      'cycle' => Cycle,
+      'render' => Render,
+      'raw' => Raw,
+      'comment' => Comment,
+      'increment' => Increment,
+      'unless' => Unless,
+      'decrement' => Decrement,
+      'capture' => Capture,
+      'continue' => Continue,
+      'include' => Include,
+      'case' => Case,
+      'ifchanged' => Ifchanged,
+      'assign' => Assign,
+      'for' => For,
+      '#' => InlineComment,
+      'break' => Break,
+      'if' => If,
+      'echo' => Echo,
+      'tablerow' => TableRow,
+    }.freeze
+  end
+end

lib/liquid/tags/assign.rb

@@ -72,6 +72,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_tag('assign', Assign)
 end

lib/liquid/tags/break.rb

@@ -26,6 +26,4 @@ module Liquid
       output
     end
   end
-
-  Template.register_tag('break', Break)
 end

lib/liquid/tags/capture.rb

@@ -39,6 +39,4 @@ module Liquid
       true
     end
   end
-
-  Template.register_tag('capture', Capture)
 end

lib/liquid/tags/case.rb

@@ -123,6 +123,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_tag('case', Case)
 end

lib/liquid/tags/comment.rb

@@ -25,7 +25,64 @@ module Liquid
     def blank?
       true
     end
-  end
 
-  Template.register_tag('comment', Comment)
+    private
+
+    def parse_body(body, tokenizer)
+      if parse_context.depth >= MAX_DEPTH
+        raise StackLevelError, "Nesting too deep"
+      end
+
+      parse_context.depth += 1
+      comment_tag_depth = 1
+
+      begin
+        # Consume tokens without creating child nodes.
+        # The children tag doesn't require to be a valid Liquid except the comment and raw tag.
+        # The child comment and raw tag must be closed.
+        while (token = tokenizer.send(:shift))
+          tag_name = if tokenizer.for_liquid_tag
+            next if token.empty? || token.match?(BlockBody::WhitespaceOrNothing)
+
+            tag_name_match = BlockBody::LiquidTagToken.match(token)
+
+            next if tag_name_match.nil?
+
+            tag_name_match[1]
+          else
+            token =~ BlockBody::FullToken
+            Regexp.last_match(2)
+          end
+
+          case tag_name
+          when "raw"
+            parse_raw_tag_body(tokenizer)
+          when "comment"
+            comment_tag_depth += 1
+          when "endcomment"
+            comment_tag_depth -= 1
+          end
+
+          if comment_tag_depth.zero?
+            parse_context.trim_whitespace = (token[-3] == WhitespaceControl) unless tokenizer.for_liquid_tag
+            return false
+          end
+        end
+
+        raise_tag_never_closed(block_name)
+      ensure
+        parse_context.depth -= 1
+      end
+
+      false
+    end
+
+    def parse_raw_tag_body(tokenizer)
+      while (token = tokenizer.send(:shift))
+        return if token =~ BlockBody::FullTokenPossiblyInvalid && "endraw" == Regexp.last_match(2)
+      end
+
+      raise_tag_never_closed("raw")
+    end
+  end
 end

lib/liquid/tags/continue.rb

@@ -17,6 +17,4 @@ module Liquid
       output
     end
   end
-
-  Template.register_tag('continue', Continue)
 end

lib/liquid/tags/cycle.rb

@@ -26,14 +26,20 @@ module Liquid
       when NamedSyntax
         @variables = variables_from_string(Regexp.last_match(2))
         @name      = parse_expression(Regexp.last_match(1))
+        @is_named = true
       when SimpleSyntax
         @variables = variables_from_string(markup)
         @name      = @variables.to_s
+        @is_named = !@name.match?(/\w+:0x\h{8}/)
       else
         raise SyntaxError, options[:locale].t("errors.syntax.cycle")
       end
     end
 
+    def named?
+      @is_named
+    end
+
     def render_to_output_buffer(context, output)
       context.registers[:cycle] ||= {}
 
@@ -62,7 +68,13 @@ module Liquid
     def variables_from_string(markup)
       markup.split(',').collect do |var|
         var =~ /\s*(#{QuotedFragment})\s*/o
-        Regexp.last_match(1) ? parse_expression(Regexp.last_match(1)) : nil
+        next unless Regexp.last_match(1)
+
+        # Expression Parser returns cached objects, and we need to dup them to
+        # start the cycle over for each new cycle call.
+        # Liquid-C does not have a cache, so we don't need to dup the object.
+        var = parse_expression(Regexp.last_match(1))
+        var.is_a?(VariableLookup) ? var.dup : var
       end.compact
     end
 
@@ -72,6 +84,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_tag('cycle', Cycle)
 end

lib/liquid/tags/decrement.rb

@@ -35,6 +35,4 @@ module Liquid
       output
     end
   end
-
-  Template.register_tag('decrement', Decrement)
 end

lib/liquid/tags/echo.rb

@@ -36,6 +36,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_tag('echo', Echo)
 end

lib/liquid/tags/for.rb

@@ -88,7 +88,7 @@ module Liquid
     end
 
     def strict_parse(markup)
-      p = Parser.new(markup)
+      p = @parse_context.new_parser(markup)
       @variable_name = p.consume(:id)
       raise SyntaxError, options[:locale].t("errors.syntax.for_invalid_in") unless p.id?('in')
 
@@ -201,6 +201,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_tag('for', For)
 end

lib/liquid/tags/if.rb

@@ -102,7 +102,7 @@ module Liquid
     end
 
     def strict_parse(markup)
-      p = Parser.new(markup)
+      p = @parse_context.new_parser(markup)
       condition = parse_binary_comparisons(p)
       p.consume(:end_of_string)
       condition
@@ -111,7 +111,7 @@ module Liquid
     def parse_binary_comparisons(p)
       condition = parse_comparison(p)
       first_condition = condition
-      while (op = (p.id?('and') || p.id?('or')))
+      while (op = p.id?('and') || p.id?('or'))
         child_condition = parse_comparison(p)
         condition.send(op, child_condition)
         condition = child_condition
@@ -135,6 +135,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_tag('if', If)
 end

lib/liquid/tags/ifchanged.rb

@@ -14,6 +14,4 @@ module Liquid
       output
     end
   end
-
-  Template.register_tag('ifchanged', Ifchanged)
 end

lib/liquid/tags/include.rb

@@ -110,6 +110,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_tag('include', Include)
 end

lib/liquid/tags/increment.rb

@@ -35,6 +35,4 @@ module Liquid
       output
     end
   end
-
-  Template.register_tag('increment', Increment)
 end

lib/liquid/tags/inline_comment.rb

@@ -25,6 +25,4 @@ module Liquid
       true
     end
   end
-
-  Template.register_tag('#', InlineComment)
 end

lib/liquid/tags/raw.rb

@@ -14,7 +14,6 @@ module Liquid
   # @liquid_syntax_keyword expression The expression to be output without being rendered.
   class Raw < Block
     Syntax = /\A\s*\z/
-    FullTokenPossiblyInvalid = /\A(.*)#{TagStart}#{WhitespaceControl}?\s*(\w+)\s*(.*)?#{WhitespaceControl}?#{TagEnd}\z/om
 
     def initialize(tag_name, markup, parse_context)
       super
@@ -25,7 +24,7 @@ module Liquid
     def parse(tokens)
       @body = +''
       while (token = tokens.shift)
-        if token =~ FullTokenPossiblyInvalid && block_delimiter == Regexp.last_match(2)
+        if token =~ BlockBody::FullTokenPossiblyInvalid && block_delimiter == Regexp.last_match(2)
           parse_context.trim_whitespace = (token[-3] == WhitespaceControl)
           @body << Regexp.last_match(1) if Regexp.last_match(1) != ""
           return
@@ -57,6 +56,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_tag('raw', Raw)
 end

lib/liquid/tags/render.rb

@@ -108,6 +108,4 @@ module Liquid
       end
     end
   end
-
-  Template.register_tag('render', Render)
 end

lib/liquid/tags/table_row.rb

@@ -65,6 +65,12 @@ module Liquid
           super
           output << '</td>'
 
+          # Handle any interrupts if they exist.
+          if context.interrupt?
+            interrupt = context.pop_interrupt
+            break if interrupt.is_a?(BreakInterrupt)
+          end
+
           if tablerowloop.col_last && !tablerowloop.last
             output << "</tr>\n<tr class=\"row#{tablerowloop.row + 1}\">"
           end
@@ -91,6 +97,4 @@ module Liquid
       raise Liquid::ArgumentError, "invalid integer"
     end
   end
-
-  Template.register_tag('tablerow', TableRow)
 end

lib/liquid/tags/unless.rb

@@ -44,6 +44,4 @@ module Liquid
       output
     end
   end
-
-  Template.register_tag('unless', Unless)
 end

lib/liquid/template.rb

@@ -18,42 +18,6 @@ module Liquid
     attr_accessor :root, :name
     attr_reader :resource_limits, :warnings
 
-    class TagRegistry
-      include Enumerable
-
-      def initialize
-        @tags  = {}
-        @cache = {}
-      end
-
-      def [](tag_name)
-        return nil unless @tags.key?(tag_name)
-        return @cache[tag_name] if Liquid.cache_classes
-
-        lookup_class(@tags[tag_name]).tap { |o| @cache[tag_name] = o }
-      end
-
-      def []=(tag_name, klass)
-        @tags[tag_name]  = klass.name
-        @cache[tag_name] = klass
-      end
-
-      def delete(tag_name)
-        @tags.delete(tag_name)
-        @cache.delete(tag_name)
-      end
-
-      def each(&block)
-        @tags.each(&block)
-      end
-
-      private
-
-      def lookup_class(name)
-        Object.const_get(name)
-      end
-    end
-
     attr_reader :profiler
 
     class << self
@@ -61,52 +25,83 @@ 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_accessor :error_mode
+      def error_mode=(mode)
-      Template.error_mode = :lax
+        Deprecations.warn("Template.error_mode=", "Environment#error_mode=")
-
+        Environment.default.error_mode = mode
-      attr_accessor :default_exception_renderer
-      Template.default_exception_renderer = lambda do |exception|
-        exception
       end
 
-      attr_accessor :file_system
+      def error_mode
-      Template.file_system = BlankFileSystem.new
+        Environment.default.error_mode
+      end
 
-      attr_accessor :tags
+      def default_exception_renderer=(renderer)
-      Template.tags = TagRegistry.new
+        Deprecations.warn("Template.default_exception_renderer=", "Environment#exception_renderer=")
-      private :tags=
+        Environment.default.exception_renderer = renderer
+      end
+
+      def default_exception_renderer
+        Environment.default.exception_renderer
+      end
+
+      def file_system=(file_system)
+        Deprecations.warn("Template.file_system=", "Environment#file_system=")
+        Environment.default.file_system = file_system
+      end
+
+      def file_system
+        Environment.default.file_system
+      end
+
+      def tags
+        Environment.default.tags
+      end
 
       def register_tag(name, klass)
-        tags[name.to_s] = klass
+        Deprecations.warn("Template.register_tag", "Environment#register_tag")
+        Environment.default.register_tag(name, klass)
       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)
-        StrainerFactory.add_global_filter(mod)
+        Deprecations.warn("Template.register_filter", "Environment#register_filter")
+        Environment.default.register_filter(mod)
       end
 
-      attr_accessor :default_resource_limits
+      private def default_resource_limits=(limits)
-      Template.default_resource_limits = {}
+        Deprecations.warn("Template.default_resource_limits=", "Environment#default_resource_limits=")
-      private :default_resource_limits=
+        Environment.default.default_resource_limits = limits
+      end
+
+      def default_resource_limits
+        Environment.default.default_resource_limits
+      end
 
       # 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 = {})
-        new.parse(source, options)
+        environment = options[:environment] || Environment.default
+        new(environment: environment).parse(source, options)
       end
     end
 
-    def initialize
+    def initialize(environment: Environment.default)
+      @environment = environment
       @rethrow_errors  = false
-      @resource_limits = ResourceLimits.new(Template.default_resource_limits)
+      @resource_limits = ResourceLimits.new(environment.default_resource_limits)
     end
 
     # Parse source code.
     # Returns self for easy chaining
     def parse(source, options = {})
       parse_context = configure_options(options)
+      source = source.to_s.to_str
+
+      unless source.valid_encoding?
+        raise TemplateEncodingError, parse_context.locale.t("errors.syntax.invalid_template_encoding")
+      end
+
       tokenizer     = parse_context.new_tokenizer(source, start_line_number: @line_numbers && 1)
       @root         = Document.parse(tokenizer, parse_context)
       self
@@ -156,11 +151,11 @@ module Liquid
         c
       when Liquid::Drop
         drop         = args.shift
-        drop.context = Context.new([drop, assigns], instance_assigns, registers, @rethrow_errors, @resource_limits)
+        drop.context = Context.new([drop, assigns], instance_assigns, registers, @rethrow_errors, @resource_limits, {}, @environment)
       when Hash
-        Context.new([args.shift, assigns], instance_assigns, registers, @rethrow_errors, @resource_limits)
+        Context.new([args.shift, assigns], instance_assigns, registers, @rethrow_errors, @resource_limits, {}, @environment)
       when nil
-        Context.new(assigns, instance_assigns, registers, @rethrow_errors, @resource_limits)
+        Context.new(assigns, instance_assigns, registers, @rethrow_errors, @resource_limits, {}, @environment)
       else
         raise ArgumentError, "Expected Hash or Liquid::Context as parameter"
       end
@@ -220,8 +215,14 @@ module Liquid
       @options      = options
       @profiling    = profiling
       @line_numbers = options[:line_numbers] || @profiling
-      parse_context = options.is_a?(ParseContext) ? options : ParseContext.new(options)
+      parse_context = if options.is_a?(ParseContext)
-      @warnings     = parse_context.warnings
+        options
+      else
+        opts = options.key?(:environment) ? options : options.merge(environment: @environment)
+        ParseContext.new(opts)
+      end
+
+      @warnings = parse_context.warnings
       parse_context
     end
 

lib/liquid/tokenizer.rb

@@ -1,20 +1,43 @@
 # frozen_string_literal: true
 
+require "strscan"
+
 module Liquid
   class Tokenizer
     attr_reader :line_number, :for_liquid_tag
 
-    def initialize(source, line_numbers = false, line_number: nil, for_liquid_tag: false)
+    TAG_END = /%\}/
-      @source         = source.to_s.to_str
+    TAG_OR_VARIABLE_START = /\{[\{\%]/
-      @line_number    = line_number || (line_numbers ? 1 : nil)
+    NEWLINE = /\n/
+
+    OPEN_CURLEY = "{".ord
+    CLOSE_CURLEY = "}".ord
+    PERCENTAGE = "%".ord
+
+    def initialize(
+      source:,
+      string_scanner:,
+      line_numbers: false,
+      line_number: nil,
+      for_liquid_tag: false
+    )
+      @line_number = line_number || (line_numbers ? 1 : nil)
       @for_liquid_tag = for_liquid_tag
-      @offset         = 0
+      @source = source.to_s.to_str
-      @tokens         = tokenize
+      @offset = 0
+      @tokens = []
+
+      if @source
+        @ss = string_scanner
+        @ss.string = @source
+        tokenize
+      end
     end
 
     def shift
       token = @tokens[@offset]
-      return nil unless token
+
+      return unless token
 
       @offset += 1
 
@@ -28,18 +51,111 @@ module Liquid
     private
 
     def tokenize
-      return [] if @source.empty?
+      if @for_liquid_tag
-
+        @tokens = @source.split("\n")
-      return @source.split("\n") if @for_liquid_tag
+      else
-
+        @tokens << shift_normal until @ss.eos?
-      tokens = @source.split(TemplateParser)
-
-      # removes the rogue empty element at the beginning of the array
-      if tokens[0]&.empty?
-        @offset += 1
       end
 
-      tokens
+      @source = nil
+      @ss = nil
+    end
+
+    def shift_normal
+      token = next_token
+
+      return unless token
+
+      token
+    end
+
+    def next_token
+      # possible states: :text, :tag, :variable
+      byte_a = @ss.peek_byte
+
+      if byte_a == OPEN_CURLEY
+        @ss.scan_byte
+
+        byte_b = @ss.peek_byte
+
+        if byte_b == PERCENTAGE
+          @ss.scan_byte
+          return next_tag_token
+        elsif byte_b == OPEN_CURLEY
+          @ss.scan_byte
+          return next_variable_token
+        end
+
+        @ss.pos -= 1
+      end
+
+      next_text_token
+    end
+
+    def next_text_token
+      start = @ss.pos
+
+      unless @ss.skip_until(TAG_OR_VARIABLE_START)
+        token = @ss.rest
+        @ss.terminate
+        return token
+      end
+
+      pos = @ss.pos -= 2
+      @source.byteslice(start, pos - start)
+    rescue ::ArgumentError => e
+      if e.message == "invalid byte sequence in #{@ss.string.encoding}"
+        raise SyntaxError, "Invalid byte sequence in #{@ss.string.encoding}"
+      else
+        raise
+      end
+    end
+
+    def next_variable_token
+      start = @ss.pos - 2
+
+      byte_a = byte_b = @ss.scan_byte
+
+      while byte_b
+        byte_a = @ss.scan_byte while byte_a && (byte_a != CLOSE_CURLEY && byte_a != OPEN_CURLEY)
+
+        break unless byte_a
+
+        if @ss.eos?
+          return byte_a == CLOSE_CURLEY ? @source.byteslice(start, @ss.pos - start) : "{{"
+        end
+
+        byte_b = @ss.scan_byte
+
+        if byte_a == CLOSE_CURLEY
+          if byte_b == CLOSE_CURLEY
+            return @source.byteslice(start, @ss.pos - start)
+          elsif byte_b != CLOSE_CURLEY
+            @ss.pos -= 1
+            return @source.byteslice(start, @ss.pos - start)
+          end
+        elsif byte_a == OPEN_CURLEY && byte_b == PERCENTAGE
+          return next_tag_token_with_start(start)
+        end
+
+        byte_a = byte_b
+      end
+
+      "{{"
+    end
+
+    def next_tag_token
+      start = @ss.pos - 2
+      if (len = @ss.skip_until(TAG_END))
+        @source.byteslice(start, len + 2)
+      else
+        "{%"
+      end
+    end
+
+    def next_tag_token_with_start(start)
+      @ss.skip_until(TAG_END)
+      @source.byteslice(start, @ss.pos - start)
     end
   end
 end

lib/liquid/utils.rb

@@ -89,5 +89,101 @@ module Liquid
       # Otherwise return the object itself
       obj
     end
+
+    def self.to_s(obj, seen = {})
+      case obj
+      when Hash
+        # If the custom hash implementation overrides `#to_s`, use their
+        # custom implementation. Otherwise we use Liquid's default
+        # implementation.
+        if obj.class.instance_method(:to_s) == HASH_TO_S_METHOD
+          hash_inspect(obj, seen)
+        else
+          obj.to_s
+        end
+      when Array
+        array_inspect(obj, seen)
+      else
+        obj.to_s
+      end
+    end
+
+    def self.inspect(obj, seen = {})
+      case obj
+      when Hash
+        # If the custom hash implementation overrides `#inspect`, use their
+        # custom implementation. Otherwise we use Liquid's default
+        # implementation.
+        if obj.class.instance_method(:inspect) == HASH_INSPECT_METHOD
+          hash_inspect(obj, seen)
+        else
+          obj.inspect
+        end
+      when Array
+        array_inspect(obj, seen)
+      else
+        obj.inspect
+      end
+    end
+
+    def self.array_inspect(arr, seen = {})
+      if seen[arr.object_id]
+        return "[...]"
+      end
+
+      seen[arr.object_id] = true
+      str = +"["
+      cursor = 0
+      len = arr.length
+
+      while cursor < len
+        if cursor > 0
+          str << ", "
+        end
+
+        item_str = inspect(arr[cursor], seen)
+        str << item_str
+        cursor += 1
+      end
+
+      str << "]"
+      str
+    ensure
+      seen.delete(arr.object_id)
+    end
+
+    def self.hash_inspect(hash, seen = {})
+      if seen[hash.object_id]
+        return "{...}"
+      end
+      seen[hash.object_id] = true
+
+      str = +"{"
+      first = true
+      hash.each do |key, value|
+        if first
+          first = false
+        else
+          str << ", "
+        end
+
+        key_str = inspect(key, seen)
+        str << key_str
+        str << "=>"
+
+        value_str = inspect(value, seen)
+        str << value_str
+      end
+      str << "}"
+      str
+    ensure
+      seen.delete(hash.object_id)
+    end
+
+    HASH_TO_S_METHOD = Hash.instance_method(:to_s)
+    private_constant :HASH_TO_S_METHOD
+
+    HASH_INSPECT_METHOD = Hash.instance_method(:inspect)
+    private_constant :HASH_INSPECT_METHOD
   end
 end

lib/liquid/variable.rb

@@ -61,14 +61,14 @@ module Liquid
 
     def strict_parse(markup)
       @filters = []
-      p = Parser.new(markup)
+      p = @parse_context.new_parser(markup)
 
       return if p.look(:end_of_string)
 
       @name = parse_context.parse_expression(p.expression)
       while p.consume?(:pipe)
         filtername = p.consume(:id)
-        filterargs = p.consume?(:colon) ? parse_filterargs(p) : []
+        filterargs = p.consume?(:colon) ? parse_filterargs(p) : Const::EMPTY_ARRAY
         @filters << parse_filter_expressions(filtername, filterargs)
       end
       p.consume(:end_of_string)
@@ -95,17 +95,23 @@ module Liquid
 
     def render_to_output_buffer(context, output)
       obj = render(context)
-
+      render_obj_to_output(obj, output)
-      if obj.is_a?(Array)
-        output << obj.join
-      elsif obj.nil?
-      else
-        output << obj.to_s
-      end
-
       output
     end
 
+    def render_obj_to_output(obj, output)
+      case obj
+      when NilClass
+        # Do nothing
+      when Array
+        obj.each do |o|
+          render_obj_to_output(o, output)
+        end
+      else
+        output << Liquid::Utils.to_s(obj)
+      end
+    end
+
     def disabled?(_context)
       false
     end

lib/liquid/variable_lookup.rb

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

lib/liquid/version.rb

@@ -2,5 +2,5 @@
 # frozen_string_literal: true
 
 module Liquid
-  VERSION = "5.4.0"
+  VERSION = "5.7.3"
 end

liquid.gemspec

@@ -13,11 +13,11 @@ Gem::Specification.new do |s|
   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.homepage    = "https://shopify.github.io/liquid/"
   s.license     = "MIT"
   # s.description = "A secure, non-evaling end user template engine with aesthetic markup."
 
-  s.required_ruby_version     = ">= 2.7.0"
+  s.required_ruby_version     = ">= 3.0.0"
   s.required_rubygems_version = ">= 1.3.7"
 
   s.metadata['allowed_push_host'] = 'https://rubygems.org'
@@ -28,6 +28,9 @@ Gem::Specification.new do |s|
 
   s.require_path = "lib"
 
+  s.add_dependency("strscan", ">= 3.1.1")
+  s.add_dependency("bigdecimal")
+
   s.add_development_dependency('rake', '~> 13.0')
   s.add_development_dependency('minitest')
 end

performance/benchmark.rb

@@ -3,18 +3,23 @@
 require 'benchmark/ips'
 require_relative 'theme_runner'
 
-Liquid::Template.error_mode = ARGV.first.to_sym if ARGV.first
+RubyVM::YJIT.enable if defined?(RubyVM::YJIT)
+Liquid::Environment.default.error_mode = ARGV.first.to_sym if ARGV.first
+
 profiler = ThemeRunner.new
 
 Benchmark.ips do |x|
-  x.time   = 10
+  x.time   = 20
-  x.warmup = 5
+  x.warmup = 10
 
   puts
   puts "Running benchmark for #{x.time} seconds (with #{x.warmup} seconds warmup)."
   puts
 
-  x.report("parse:") { profiler.compile }
+  phase = ENV["PHASE"] || "all"
-  x.report("render:") { profiler.render }
+
-  x.report("parse & render:") { profiler.run }
+  x.report("tokenize:") { profiler.tokenize } if phase == "all" || phase == "tokenize"
+  x.report("parse:") { profiler.compile } if phase == "all" || phase == "parse"
+  x.report("render:") { profiler.render } if phase == "all" || phase == "render"
+  x.report("parse & render:") { profiler.run } if phase == "all" || phase == "run"
 end

performance/shopify/liquid.rb

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

performance/theme_runner.rb

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

performance/unit/expression_benchmark.rb

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

performance/unit/lexer_benchmark.rb

@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+require "benchmark/ips"
+
+# benchmark liquid lexing
+
+require 'liquid'
+
+RubyVM::YJIT.enable
+
+EXPRESSIONS = [
+  "foo[1..2].baz",
+  "12.0",
+  "foo.bar.based",
+  "21 - 62",
+  "foo.bar.baz",
+  "foo > 12",
+  "foo < 12",
+  "foo <= 12",
+  "foo >= 12",
+  "foo <> 12",
+  "foo == 12",
+  "foo != 12",
+  "foo contains 12",
+  "foo contains 'bar'",
+  "foo != 'bar'",
+  "'foo' contains 'bar'",
+  '234089',
+  "foo | default: -1",
+]
+
+Benchmark.ips do |x|
+  x.config(time: 10, warmup: 5)
+
+  x.report("Liquid::Lexer#tokenize") do
+    EXPRESSIONS.each do |expr|
+      l = Liquid::Lexer.new(expr)
+      l.tokenize
+    end
+  end
+
+  x.compare!
+end

test/integration/context_test.rb

@@ -36,6 +36,24 @@ class Category
   end
 end
 
+class ProductsDrop < Liquid::Drop
+  def initialize(products)
+    @products = products
+  end
+
+  def size
+    @products.size
+  end
+
+  def to_liquid
+    if @context["forloop"]
+      @products.first(@context["forloop"].length)
+    else
+      @products
+    end
+  end
+end
+
 class CategoryDrop < Liquid::Drop
   attr_accessor :category, :context
 
@@ -635,6 +653,40 @@ class ContextTest < Minitest::Test
     assert_equal(:my_value, c.registers[:my_register])
   end
 
+  def test_variable_to_liquid_returns_contextual_drop
+    context = {
+      "products" => ProductsDrop.new(["A", "B", "C", "D", "E"]),
+    }
+
+    template = Liquid::Template.parse(<<~LIQUID)
+      {%- for i in (1..3) -%}
+        for_loop_products_count: {{ products | size }}
+      {% endfor %}
+
+      unscoped_products_count: {{ products | size }}
+    LIQUID
+
+    result = template.render(context)
+
+    assert_includes(result, "for_loop_products_count: 3")
+    assert_includes(result, "unscoped_products_count: 5")
+  end
+
+  def test_new_isolated_context_inherits_parent_environment
+    global_environment = Liquid::Environment.build(tags: {})
+    context = Context.build(environment: global_environment)
+
+    subcontext = context.new_isolated_subcontext
+    assert_equal(global_environment, subcontext.environment)
+  end
+
+  def test_newly_built_context_inherits_parent_environment
+    global_environment = Liquid::Environment.build(tags: {})
+    context = Context.build(environment: global_environment)
+    assert_equal(global_environment, context.environment)
+    assert(context.environment.tags.each.to_a.empty?)
+  end
+
   private
 
   def assert_no_object_allocations

test/integration/error_handling_test.rb

@@ -203,20 +203,34 @@ class ErrorHandlingTest < Minitest::Test
   end
 
   def test_setting_default_exception_renderer
-    old_exception_renderer = Liquid::Template.default_exception_renderer
     exceptions = []
-    Liquid::Template.default_exception_renderer = ->(e) {
+    default_exception_renderer = ->(e) {
       exceptions << e
       ''
     }
-    template = Liquid::Template.parse('This is a runtime error: {{ errors.argument_error }}')
+
+    env = Liquid::Environment.build(exception_renderer: default_exception_renderer)
+    template = Liquid::Template.parse('This is a runtime error: {{ errors.argument_error }}', environment: env)
 
     output = template.render('errors' => ErrorDrop.new)
 
     assert_equal('This is a runtime error: ', output)
     assert_equal([Liquid::ArgumentError], template.errors.map(&:class))
-  ensure
+  end
-    Liquid::Template.default_exception_renderer = old_exception_renderer if old_exception_renderer
+
+  def test_setting_exception_renderer_on_environment
+    exceptions = []
+    exception_renderer = ->(e) do
+      exceptions << e
+      ''
+    end
+
+    environment = Liquid::Environment.build(exception_renderer: exception_renderer)
+    template = Liquid::Template.parse('This is a runtime error: {{ errors.argument_error }}', environment: environment)
+    output = template.render('errors' => ErrorDrop.new)
+
+    assert_equal('This is a runtime error: ', output)
+    assert_equal([Liquid::ArgumentError], template.errors.map(&:class))
   end
 
   def test_exception_renderer_exposing_non_liquid_error
@@ -242,16 +256,10 @@ class ErrorHandlingTest < Minitest::Test
   end
 
   def test_included_template_name_with_line_numbers
-    old_file_system = Liquid::Template.file_system
+    environment = Liquid::Environment.build(file_system: TestFileSystem.new)
+    template = Liquid::Template.parse("Argument error:\n{% include 'product' %}", line_numbers: true, environment: environment)
+    page     = template.render('errors' => ErrorDrop.new)
 
-    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)
-    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)
   end

test/integration/expression_test.rb

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

test/integration/hash_rendering_test.rb

@@ -0,0 +1,106 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class HashRenderingTest < Minitest::Test
+  def test_render_empty_hash
+    assert_template_result("{}", "{{ my_hash }}", { "my_hash" => {} })
+  end
+
+  def test_render_hash_with_string_keys_and_values
+    assert_template_result("{\"key1\"=>\"value1\", \"key2\"=>\"value2\"}", "{{ my_hash }}", { "my_hash" => { "key1" => "value1", "key2" => "value2" } })
+  end
+
+  def test_render_hash_with_symbol_keys_and_integer_values
+    assert_template_result("{:key1=>1, :key2=>2}", "{{ my_hash }}", { "my_hash" => { key1: 1, key2: 2 } })
+  end
+
+  def test_render_nested_hash
+    assert_template_result("{\"outer\"=>{\"inner\"=>\"value\"}}", "{{ my_hash }}", { "my_hash" => { "outer" => { "inner" => "value" } } })
+  end
+
+  def test_render_hash_with_array_values
+    assert_template_result("{\"numbers\"=>[1, 2, 3]}", "{{ my_hash }}", { "my_hash" => { "numbers" => [1, 2, 3] } })
+  end
+
+  def test_render_recursive_hash
+    recursive_hash = { "self" => {} }
+    recursive_hash["self"]["self"] = recursive_hash
+    assert_template_result("{\"self\"=>{\"self\"=>{...}}}", "{{ my_hash }}", { "my_hash" => recursive_hash })
+  end
+
+  def test_hash_with_downcase_filter
+    assert_template_result("{\"key\"=>\"value\", \"anotherkey\"=>\"anothervalue\"}", "{{ my_hash | downcase }}", { "my_hash" => { "Key" => "Value", "AnotherKey" => "AnotherValue" } })
+  end
+
+  def test_hash_with_upcase_filter
+    assert_template_result("{\"KEY\"=>\"VALUE\", \"ANOTHERKEY\"=>\"ANOTHERVALUE\"}", "{{ my_hash | upcase }}", { "my_hash" => { "Key" => "Value", "AnotherKey" => "AnotherValue" } })
+  end
+
+  def test_hash_with_strip_filter
+    assert_template_result("{\"Key\"=>\"Value\", \"AnotherKey\"=>\"AnotherValue\"}", "{{ my_hash | strip }}", { "my_hash" => { "Key" => "Value", "AnotherKey" => "AnotherValue" } })
+  end
+
+  def test_hash_with_escape_filter
+    assert_template_result("{&quot;Key&quot;=&gt;&quot;Value&quot;, &quot;AnotherKey&quot;=&gt;&quot;AnotherValue&quot;}", "{{ my_hash | escape }}", { "my_hash" => { "Key" => "Value", "AnotherKey" => "AnotherValue" } })
+  end
+
+  def test_hash_with_url_encode_filter
+    assert_template_result("%7B%22Key%22%3D%3E%22Value%22%2C+%22AnotherKey%22%3D%3E%22AnotherValue%22%7D", "{{ my_hash | url_encode }}", { "my_hash" => { "Key" => "Value", "AnotherKey" => "AnotherValue" } })
+  end
+
+  def test_hash_with_strip_html_filter
+    assert_template_result("{\"Key\"=>\"Value\", \"AnotherKey\"=>\"AnotherValue\"}", "{{ my_hash | strip_html }}", { "my_hash" => { "Key" => "Value", "AnotherKey" => "AnotherValue" } })
+  end
+
+  def test_hash_with_truncate__20_filter
+    assert_template_result("{\"Key\"=>\"Value\", ...", "{{ my_hash | truncate: 20 }}", { "my_hash" => { "Key" => "Value", "AnotherKey" => "AnotherValue" } })
+  end
+
+  def test_hash_with_replace___key____replaced_key__filter
+    assert_template_result("{\"Key\"=>\"Value\", \"AnotherKey\"=>\"AnotherValue\"}", "{{ my_hash | replace: 'key', 'replaced_key' }}", { "my_hash" => { "Key" => "Value", "AnotherKey" => "AnotherValue" } })
+  end
+
+  def test_hash_with_append____appended_text__filter
+    assert_template_result("{\"Key\"=>\"Value\", \"AnotherKey\"=>\"AnotherValue\"} appended text", "{{ my_hash | append: ' appended text' }}", { "my_hash" => { "Key" => "Value", "AnotherKey" => "AnotherValue" } })
+  end
+
+  def test_hash_with_prepend___prepended_text___filter
+    assert_template_result("prepended text {\"Key\"=>\"Value\", \"AnotherKey\"=>\"AnotherValue\"}", "{{ my_hash | prepend: 'prepended text ' }}", { "my_hash" => { "Key" => "Value", "AnotherKey" => "AnotherValue" } })
+  end
+
+  def test_render_hash_with_array_values_empty
+    assert_template_result("{\"numbers\"=>[]}", "{{ my_hash }}", { "my_hash" => { "numbers" => [] } })
+  end
+
+  def test_render_hash_with_array_values_hash
+    assert_template_result("{\"numbers\"=>[{:foo=>42}]}", "{{ my_hash }}", { "my_hash" => { "numbers" => [{ foo: 42 }] } })
+  end
+
+  def test_join_filter_with_hash
+    array = [{ "key1" => "value1" }, { "key2" => "value2" }]
+    glue = { "lol" => "wut" }
+    assert_template_result("{\"key1\"=>\"value1\"}{\"lol\"=>\"wut\"}{\"key2\"=>\"value2\"}", "{{ my_array | join: glue }}", { "my_array" => array, "glue" => glue })
+  end
+
+  def test_render_hash_with_hash_key
+    assert_template_result("{{\"foo\"=>\"bar\"}=>42}", "{{ my_hash }}", { "my_hash" => { Hash["foo" => "bar"] => 42 } })
+  end
+
+  def test_rendering_hash_with_custom_to_s_method_uses_custom_to_s
+    my_hash = Class.new(Hash) do
+      def to_s
+        "kewl"
+      end
+    end.new
+
+    assert_template_result("kewl", "{{ my_hash }}", { "my_hash" => my_hash })
+  end
+
+  def test_rendering_hash_without_custom_to_s_uses_default_inspect
+    my_hash = Class.new(Hash).new
+    my_hash[:foo] = :bar
+
+    assert_template_result("{:foo=>:bar}", "{{ my_hash }}", { "my_hash" => my_hash })
+  end
+end

test/integration/parsing_quirks_test.rb

@@ -131,4 +131,24 @@ class ParsingQuirksTest < Minitest::Test
   def test_contains_in_id
     assert_template_result(' YES ', '{% if containsallshipments == true %} YES {% endif %}', { 'containsallshipments' => true })
   end
+
+  def test_incomplete_expression
+    with_error_mode(:lax) do
+      assert_template_result("false", "{{ false - }}")
+      assert_template_result("false", "{{ false > }}")
+      assert_template_result("false", "{{ false < }}")
+      assert_template_result("false", "{{ false = }}")
+      assert_template_result("false", "{{ false ! }}")
+      assert_template_result("false", "{{ false 1 }}")
+      assert_template_result("false", "{{ false a }}")
+
+      assert_template_result("false", "{% liquid assign foo = false -\n%}{{ foo }}")
+      assert_template_result("false", "{% liquid assign foo = false >\n%}{{ foo }}")
+      assert_template_result("false", "{% liquid assign foo = false <\n%}{{ foo }}")
+      assert_template_result("false", "{% liquid assign foo = false =\n%}{{ foo }}")
+      assert_template_result("false", "{% liquid assign foo = false !\n%}{{ foo }}")
+      assert_template_result("false", "{% liquid assign foo = false 1\n%}{{ foo }}")
+      assert_template_result("false", "{% liquid assign foo = false a\n%}{{ foo }}")
+    end
+  end
 end # ParsingQuirksTest

test/integration/profiler_test.rb

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

test/integration/standard_filter_test.rb

@@ -32,7 +32,7 @@ class TestDrop < Liquid::Drop
   attr_reader :value
 
   def registers
-    { @value => @context.registers[@value] }
+    "{#{@value.inspect}=>#{@context.registers[@value].inspect}}"
   end
 end
 
@@ -133,6 +133,18 @@ class StandardFiltersTest < Minitest::Test
     assert_equal([], @filters.slice(input, -(1 << 63), 6))
   end
 
+  def test_find_on_empty_array
+    assert_nil(@filters.find([], 'foo', 'bar'))
+  end
+
+  def test_find_index_on_empty_array
+    assert_nil(@filters.find_index([], 'foo', 'bar'))
+  end
+
+  def test_has_on_empty_array
+    refute(@filters.has([], 'foo', 'bar'))
+  end
+
   def test_truncate
     assert_equal('1234...', @filters.truncate('1234567890', 7))
     assert_equal('1234567890', @filters.truncate('1234567890', 20))
@@ -176,7 +188,17 @@ class StandardFiltersTest < Minitest::Test
   end
 
   def test_base64_decode
-    assert_equal('one two three', @filters.base64_decode('b25lIHR3byB0aHJlZQ=='))
+    decoded = @filters.base64_decode('b25lIHR3byB0aHJlZQ==')
+    assert_equal('one two three', decoded)
+    assert_equal(Encoding::UTF_8, decoded.encoding)
+
+    decoded = @filters.base64_decode('4pyF')
+    assert_equal('✅', decoded)
+    assert_equal(Encoding::UTF_8, decoded.encoding)
+
+    decoded = @filters.base64_decode("/w==")
+    assert_equal(Encoding::ASCII_8BIT, decoded.encoding)
+    assert_equal((+"\xFF").force_encoding(Encoding::ASCII_8BIT), decoded)
 
     exception = assert_raises(Liquid::ArgumentError) do
       @filters.base64_decode("invalidbase64")
@@ -194,10 +216,21 @@ class StandardFiltersTest < Minitest::Test
   end
 
   def test_base64_url_safe_decode
+    decoded = @filters.base64_url_safe_decode('YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXogQUJDREVGR0hJSktMTU5PUFFSU1RVVldYWVogMTIzNDU2Nzg5MCAhQCMkJV4mKigpLT1fKy8_Ljo7W117fVx8')
     assert_equal(
       'abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ 1234567890 !@#$%^&*()-=_+/?.:;[]{}\|',
-      @filters.base64_url_safe_decode('YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXogQUJDREVGR0hJSktMTU5PUFFSU1RVVldYWVogMTIzNDU2Nzg5MCAhQCMkJV4mKigpLT1fKy8_Ljo7W117fVx8'),
+      decoded,
     )
+    assert_equal(Encoding::UTF_8, decoded.encoding)
+
+    decoded = @filters.base64_url_safe_decode('4pyF')
+    assert_equal('✅', decoded)
+    assert_equal(Encoding::UTF_8, decoded.encoding)
+
+    decoded = @filters.base64_url_safe_decode("_w==")
+    assert_equal(Encoding::ASCII_8BIT, decoded.encoding)
+    assert_equal((+"\xFF").force_encoding(Encoding::ASCII_8BIT), decoded)
+
     exception = assert_raises(Liquid::ArgumentError) do
       @filters.base64_url_safe_decode("invalidbase64")
     end
@@ -260,6 +293,16 @@ class StandardFiltersTest < Minitest::Test
     assert_equal('1121314', @filters.join([1, 2, 3, 4], 1))
   end
 
+  def test_join_calls_to_liquid_on_each_element
+    drop = Class.new(Liquid::Drop) do
+      def to_liquid
+        'i did it'
+      end
+    end
+
+    assert_equal('i did it, i did it', @filters.join([drop.new, drop.new], ", "))
+  end
+
   def test_sort
     assert_equal([1, 2, 3, 4], @filters.sort([4, 3, 2, 1]))
     assert_equal([{ "a" => 1 }, { "a" => 2 }, { "a" => 3 }, { "a" => 4 }], @filters.sort([{ "a" => 4 }, { "a" => 3 }, { "a" => 1 }, { "a" => 2 }], "a"))
@@ -310,8 +353,8 @@ class StandardFiltersTest < Minitest::Test
       { "price" => "1", "handle" => "gamma" },
       { "price" => 2, "handle" => "epsilon" },
       { "price" => "4", "handle" => "alpha" },
-      { "handle" => "delta" },
       { "handle" => "beta" },
+      { "handle" => "delta" },
     ]
     assert_equal(expectation, @filters.sort_natural(input, "price"))
   end
@@ -806,21 +849,216 @@ class StandardFiltersTest < Minitest::Test
     assert_template_result('abc', "{{ 'abc' | date: '%D' }}")
   end
 
-  def test_where
+  def test_reject
-    input = [
+    array = [
       { "handle" => "alpha", "ok" => true },
       { "handle" => "beta", "ok" => false },
       { "handle" => "gamma", "ok" => false },
       { "handle" => "delta", "ok" => true },
     ]
 
-    expectation = [
+    template = "{{ array | reject: 'ok' | map: 'handle' | join: ' ' }}"
+    expected_output = "beta gamma"
+
+    assert_template_result(expected_output, template, { "array" => array })
+  end
+
+  def test_reject_with_value
+    array = [
       { "handle" => "alpha", "ok" => true },
+      { "handle" => "beta", "ok" => false },
+      { "handle" => "gamma", "ok" => false },
       { "handle" => "delta", "ok" => true },
     ]
 
-    assert_equal(expectation, @filters.where(input, "ok", true))
+    template = "{{ array | reject: 'ok', true | map: 'handle' | join: ' ' }}"
-    assert_equal(expectation, @filters.where(input, "ok"))
+    expected_output = "beta gamma"
+
+    assert_template_result(expected_output, template, { "array" => array })
+  end
+
+  def test_reject_with_false_value
+    array = [
+      { "handle" => "alpha", "ok" => true },
+      { "handle" => "beta", "ok" => false },
+      { "handle" => "gamma", "ok" => false },
+      { "handle" => "delta", "ok" => true },
+    ]
+
+    template = "{{ array | reject: 'ok', false | map: 'handle' | join: ' ' }}"
+    expected_output = "alpha delta"
+
+    assert_template_result(expected_output, template, { "array" => array })
+  end
+
+  def test_has
+    array = [
+      { "handle" => "alpha", "ok" => true },
+      { "handle" => "beta", "ok" => false },
+      { "handle" => "gamma", "ok" => false },
+      { "handle" => "delta", "ok" => false },
+    ]
+
+    expected_output = "true"
+
+    assert_template_result(expected_output, "{{ array | has: 'ok' }}", { "array" => array })
+    assert_template_result(expected_output, "{{ array | has: 'ok', true }}", { "array" => array })
+  end
+
+  def test_has_when_does_not_have_it
+    array = [
+      { "handle" => "alpha", "ok" => false },
+      { "handle" => "beta", "ok" => false },
+      { "handle" => "gamma", "ok" => false },
+      { "handle" => "delta", "ok" => false },
+    ]
+
+    expected_output = "false"
+
+    assert_template_result(expected_output, "{{ array | has: 'ok' }}", { "array" => array })
+    assert_template_result(expected_output, "{{ array | has: 'ok', true }}", { "array" => array })
+  end
+
+  def test_has_with_empty_arrays
+    template = <<~LIQUID
+      {%- assign has_product = products | has: 'title.content', 'Not found' -%}
+      {%- unless has_product -%}
+        Product not found.
+      {%- endunless -%}
+    LIQUID
+    expected_output = "Product not found."
+
+    assert_template_result(expected_output, template, { "products" => [] })
+  end
+
+  def test_has_with_false_value
+    array = [
+      { "handle" => "alpha", "ok" => true },
+      { "handle" => "beta", "ok" => false },
+      { "handle" => "gamma", "ok" => false },
+      { "handle" => "delta", "ok" => true },
+    ]
+
+    template = "{{ array | has: 'ok', false }}"
+    expected_output = "true"
+
+    assert_template_result(expected_output, template, { "array" => array })
+  end
+
+  def test_has_with_false_value_when_does_not_have_it
+    array = [
+      { "handle" => "alpha", "ok" => true },
+      { "handle" => "beta", "ok" => true },
+      { "handle" => "gamma", "ok" => true },
+      { "handle" => "delta", "ok" => true },
+    ]
+
+    template = "{{ array | has: 'ok', false }}"
+    expected_output = "false"
+
+    assert_template_result(expected_output, template, { "array" => array })
+  end
+
+  def test_find_with_value
+    products = [
+      { "title" => "Pro goggles",    "price" => 1299 },
+      { "title" => "Thermal gloves", "price" => 1499 },
+      { "title" => "Alpine jacket",  "price" => 3999 },
+      { "title" => "Mountain boots", "price" => 3899 },
+      { "title" => "Safety helmet",  "price" => 1999 }
+    ]
+
+    template = <<~LIQUID
+      {%- assign product = products | find: 'price', 3999 -%}
+      {{- product.title -}}
+    LIQUID
+    expected_output = "Alpine jacket"
+
+    assert_template_result(expected_output, template, { "products" => products })
+  end
+
+  def test_find_with_empty_arrays
+    template = <<~LIQUID
+      {%- assign product = products | find: 'title.content', 'Not found' -%}
+      {%- unless product -%}
+        Product not found.
+      {%- endunless -%}
+    LIQUID
+    expected_output = "Product not found."
+
+    assert_template_result(expected_output, template, { "products" => [] })
+  end
+
+  def test_find_index_with_value
+    products = [
+      { "title" => "Pro goggles",    "price" => 1299 },
+      { "title" => "Thermal gloves", "price" => 1499 },
+      { "title" => "Alpine jacket",  "price" => 3999 },
+      { "title" => "Mountain boots", "price" => 3899 },
+      { "title" => "Safety helmet",  "price" => 1999 }
+    ]
+
+    template = <<~LIQUID
+      {%- assign index = products | find_index: 'price', 3999 -%}
+      {{- index -}}
+    LIQUID
+    expected_output = "2"
+
+    assert_template_result(expected_output, template, { "products" => products })
+  end
+
+  def test_find_index_with_empty_arrays
+    template = <<~LIQUID
+      {%- assign index = products | find_index: 'title.content', 'Not found' -%}
+      {%- unless index -%}
+        Index not found.
+      {%- endunless -%}
+    LIQUID
+    expected_output = "Index not found."
+
+    assert_template_result(expected_output, template, { "products" => [] })
+  end
+
+  def test_where
+    array = [
+      { "handle" => "alpha", "ok" => true },
+      { "handle" => "beta", "ok" => false },
+      { "handle" => "gamma", "ok" => false },
+      { "handle" => "delta", "ok" => true },
+    ]
+
+    template = "{{ array | where: 'ok' | map: 'handle' | join: ' ' }}"
+    expected_output = "alpha delta"
+
+    assert_template_result(expected_output, template, { "array" => array })
+  end
+
+  def test_where_with_value
+    array = [
+      { "handle" => "alpha", "ok" => true },
+      { "handle" => "beta", "ok" => false },
+      { "handle" => "gamma", "ok" => false },
+      { "handle" => "delta", "ok" => true },
+    ]
+
+    template = "{{ array | where: 'ok', true | map: 'handle' | join: ' ' }}"
+    expected_output = "alpha delta"
+
+    assert_template_result(expected_output, template, { "array" => array })
+  end
+
+  def test_where_with_false_value
+    array = [
+      { "handle" => "alpha", "ok" => true },
+      { "handle" => "beta", "ok" => false },
+      { "handle" => "gamma", "ok" => false },
+      { "handle" => "delta", "ok" => true },
+    ]
+
+    template = "{{ array | where: 'ok', false | map: 'handle' | join: ' ' }}"
+    expected_output = "beta gamma"
+
+    assert_template_result(expected_output, template, { "array" => array })
   end
 
   def test_where_string_keys
@@ -994,6 +1232,42 @@ class StandardFiltersTest < Minitest::Test
     assert(t.foo > 0)
   end
 
+  def test_sum_of_floats
+    input = [0.1, 0.2, 0.3]
+    assert_equal(0.6, @filters.sum(input))
+    assert_template_result("0.6", "{{ input | sum }}", { "input" => input })
+  end
+
+  def test_sum_of_negative_floats
+    input = [0.1, 0.2, -0.3]
+    assert_equal(0.0, @filters.sum(input))
+    assert_template_result("0.0", "{{ input | sum }}", { "input" => input })
+  end
+
+  def test_sum_with_float_strings
+    input = [0.1, "0.2", "0.3"]
+    assert_equal(0.6, @filters.sum(input))
+    assert_template_result("0.6", "{{ input | sum }}", { "input" => input })
+  end
+
+  def test_sum_resulting_in_negative_float
+    input = [0.1, -0.2, -0.3]
+    assert_equal(-0.4, @filters.sum(input))
+    assert_template_result("-0.4", "{{ input | sum }}", { "input" => input })
+  end
+
+  def test_sum_with_floats_and_indexable_map_values
+    input = [{ "quantity" => 1 }, { "quantity" => 0.2, "weight" => -0.3 }, { "weight" => 0.4 }]
+    assert_equal(0.0, @filters.sum(input))
+    assert_equal(1.2, @filters.sum(input, "quantity"))
+    assert_equal(0.1, @filters.sum(input, "weight"))
+    assert_equal(0.0, @filters.sum(input, "subtotal"))
+    assert_template_result("0", "{{ input | sum }}", { "input" => input })
+    assert_template_result("1.2", "{{ input | sum: 'quantity' }}", { "input" => input })
+    assert_template_result("0.1", "{{ input | sum: 'weight' }}", { "input" => input })
+    assert_template_result("0", "{{ input | sum: 'subtotal' }}", { "input" => input })
+  end
+
   private
 
   def with_timezone(tz)

test/integration/tags/cycle_tag_test.rb

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

test/integration/tags/include_tag_test.rb

@@ -49,14 +49,6 @@ end
 class IncludeTagTest < Minitest::Test
   include Liquid
 
-  def setup
-    @default_file_system = Liquid::Template.file_system
-  end
-
-  def teardown
-    Liquid::Template.file_system = @default_file_system
-  end
-
   def test_include_tag_looks_for_file_system_in_registers_first
     assert_equal(
       'from OtherFileSystem',
@@ -182,10 +174,10 @@ class IncludeTagTest < Minitest::Test
       end
     end
 
-    Liquid::Template.file_system = infinite_file_system.new
+    env = Liquid::Environment.build(file_system: infinite_file_system.new)
 
     assert_raises(Liquid::StackLevelError) do
-      Template.parse("{% include 'loop' %}").render!
+      Template.parse("{% include 'loop' %}", environment: env).render!
     end
   end
 
@@ -214,9 +206,10 @@ class IncludeTagTest < Minitest::Test
 
   def test_include_tag_caches_second_read_of_same_partial
     file_system = CountingFileSystem.new
+    environment = Liquid::Environment.build(file_system: file_system)
     assert_equal(
       'from CountingFileSystemfrom CountingFileSystem',
-      Template.parse("{% include 'pick_a_source' %}{% include 'pick_a_source' %}").render!({}, registers: { file_system: file_system }),
+      Template.parse("{% include 'pick_a_source' %}{% include 'pick_a_source' %}", environment: environment).render!({}, registers: { file_system: file_system }),
     )
     assert_equal(1, file_system.count)
   end
@@ -271,26 +264,27 @@ class IncludeTagTest < Minitest::Test
   end
 
   def test_does_not_add_error_in_strict_mode_for_missing_variable
-    Liquid::Template.file_system = TestFileSystem.new
+    env = Liquid::Environment.build(file_system: TestFileSystem.new)
 
-    a = Liquid::Template.parse(' {% include "nested_template" %}')
+    a = Liquid::Template.parse(' {% include "nested_template" %}', environment: env)
     a.render!
     assert_empty(a.errors)
   end
 
   def test_passing_options_to_included_templates
-    Liquid::Template.file_system = TestFileSystem.new
+    env = Liquid::Environment.build(file_system: TestFileSystem.new)
+
     assert_raises(Liquid::SyntaxError) do
-      Template.parse("{% include template %}", error_mode: :strict).render!("template" => '{{ "X" || downcase }}')
+      Template.parse("{% include template %}", error_mode: :strict, environment: env).render!("template" => '{{ "X" || downcase }}')
     end
     with_error_mode(:lax) do
-      assert_equal('x', Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: true).render!("template" => '{{ "X" || downcase }}'))
+      assert_equal('x', Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: true, environment: env).render!("template" => '{{ "X" || downcase }}'))
     end
     assert_raises(Liquid::SyntaxError) do
-      Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: [:locale]).render!("template" => '{{ "X" || downcase }}')
+      Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: [:locale], environment: env).render!("template" => '{{ "X" || downcase }}')
     end
     with_error_mode(:lax) do
-      assert_equal('x', Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: [:error_mode]).render!("template" => '{{ "X" || downcase }}'))
+      assert_equal('x', Template.parse("{% include template %}", error_mode: :strict, include_options_blacklist: [:error_mode], environment: env).render!("template" => '{{ "X" || downcase }}'))
     end
   end
 
@@ -341,8 +335,11 @@ class IncludeTagTest < Minitest::Test
   end
 
   def test_including_with_strict_variables
-    Liquid::Template.file_system = StubFileSystem.new({ "simple" => "simple" })
+    env = Liquid::Environment.build(
-    template = Liquid::Template.parse("{% include 'simple' %}", error_mode: :warn)
+      file_system: StubFileSystem.new('simple' => 'simple'),
+    )
+
+    template = Liquid::Template.parse("{% include 'simple' %}", error_mode: :warn, environment: env)
     template.render(nil, strict_variables: true)
 
     assert_equal([], template.errors)

test/integration/tags/raw_tag_test.rb

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

test/integration/tags/render_tag_test.rb

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

test/integration/tags/table_row_test.rb

@@ -207,4 +207,52 @@ class TableRowTest < Minitest::Test
       render_errors: true,
     )
   end
+
+  def test_table_row_handles_interrupts
+    assert_template_result(
+      "<tr class=\"row1\">\n<td class=\"col1\"> 1 </td></tr>\n",
+      '{% tablerow n in (1...3) cols:2 %} {{n}} {% break %} {{n}} {% endtablerow %}',
+    )
+
+    assert_template_result(
+      "<tr class=\"row1\">\n<td class=\"col1\"> 1 </td><td class=\"col2\"> 2 </td></tr>\n<tr class=\"row2\"><td class=\"col1\"> 3 </td></tr>\n",
+      '{% tablerow n in (1...3) cols:2 %} {{n}} {% continue %} {{n}} {% endtablerow %}',
+    )
+  end
+
+  def test_table_row_does_not_leak_interrupts
+    template = <<~LIQUID
+      {% for i in (1..2) -%}
+      {% for j in (1..2) -%}
+      {% tablerow k in (1..3) %}{% break %}{% endtablerow -%}
+      loop j={{ j }}
+      {% endfor -%}
+      loop i={{ i }}
+      {% endfor -%}
+      after loop
+    LIQUID
+
+    expected = <<~STR
+      <tr class="row1">
+      <td class="col1"></td></tr>
+      loop j=1
+      <tr class="row1">
+      <td class="col1"></td></tr>
+      loop j=2
+      loop i=1
+      <tr class="row1">
+      <td class="col1"></td></tr>
+      loop j=1
+      <tr class="row1">
+      <td class="col1"></td></tr>
+      loop j=2
+      loop i=2
+      after loop
+    STR
+
+    assert_template_result(
+      expected,
+      template,
+    )
+  end
 end

test/integration/template_test.rb

@@ -337,4 +337,22 @@ class TemplateTest < Minitest::Test
     assert_equal("x=2", output)
     assert_instance_of(String, output)
   end
+
+  def test_raises_error_with_invalid_utf8
+    e = assert_raises(TemplateEncodingError) do
+      Template.parse(<<~LIQUID)
+        {% comment %}
+          \xC0
+        {% endcomment %}
+      LIQUID
+    end
+
+    assert_equal('Liquid error: Invalid template encoding', e.message)
+  end
+
+  def test_allows_non_string_values_as_source
+    assert_equal('', Template.parse(nil).render)
+    assert_equal('1', Template.parse(1).render)
+    assert_equal('true', Template.parse(true).render)
+  end
 end

test/integration/variable_test.rb

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

test/test_helper.rb

@@ -13,12 +13,7 @@ if (env_mode = ENV['LIQUID_PARSER_MODE'])
   puts "-- #{env_mode.upcase} ERROR MODE"
   mode = env_mode.to_sym
 end
-Liquid::Template.error_mode = mode
+Liquid::Environment.default.error_mode = mode
-
-if ENV['LIQUID_C'] == '1'
-  puts "-- LIQUID C"
-  require 'liquid/c'
-end
 
 if Minitest.const_defined?('Test')
   # We're on Minitest 5+. Nothing to do here.
@@ -42,10 +37,11 @@ module Minitest
       message: nil, partials: nil, error_mode: nil, render_errors: false,
       template_factory: nil
     )
-      template = Liquid::Template.parse(template, line_numbers: true, error_mode: error_mode&.to_sym)
       file_system = StubFileSystem.new(partials || {})
+      environment = Liquid::Environment.build(file_system: file_system)
+      template = Liquid::Template.parse(template, line_numbers: true, error_mode: error_mode&.to_sym, environment: environment)
       registers = Liquid::Registers.new(file_system: file_system, template_factory: template_factory)
-      context = Liquid::Context.build(static_environments: assigns, rethrow_errors: !render_errors, registers: registers)
+      context = Liquid::Context.build(static_environments: assigns, rethrow_errors: !render_errors, registers: registers, environment: environment)
       output = template.render(context)
       assert_equal(expected, output, message)
     end
@@ -78,44 +74,27 @@ module Minitest
       assert_equal(times, calls, "Number of calls to Usage.increment with #{name.inspect}")
     end
 
-    def with_global_filter(*globals)
+    def with_global_filter(*globals, &blk)
-      original_global_cache = Liquid::StrainerFactory::GlobalCache
+      environment = Liquid::Environment.build do |w|
-      Liquid::StrainerFactory.send(:remove_const, :GlobalCache)
+        w.register_filters(globals)
-      Liquid::StrainerFactory.const_set(:GlobalCache, Class.new(Liquid::StrainerTemplate))
+      end
 
-      globals.each do |global|
+      Environment.dangerously_override(environment, &blk)
-        Liquid::Template.register_filter(global)
-      end
-      Liquid::StrainerFactory.send(:strainer_class_cache).clear
-      begin
-        yield
-      ensure
-        Liquid::StrainerFactory.send(:remove_const, :GlobalCache)
-        Liquid::StrainerFactory.const_set(:GlobalCache, original_global_cache)
-        Liquid::StrainerFactory.send(:strainer_class_cache).clear
-      end
     end
 
     def with_error_mode(mode)
-      old_mode = Liquid::Template.error_mode
+      old_mode = Liquid::Environment.default.error_mode
-      Liquid::Template.error_mode = mode
+      Liquid::Environment.default.error_mode = mode
       yield
     ensure
-      Liquid::Template.error_mode = old_mode
+      Liquid::Environment.default.error_mode = old_mode
     end
 
-    def with_custom_tag(tag_name, tag_class)
+    def with_custom_tag(tag_name, tag_class, &block)
-      old_tag = Liquid::Template.tags[tag_name]
+      environment = Liquid::Environment.default.dup
-      begin
+      environment.register_tag(tag_name, tag_class)
-        Liquid::Template.register_tag(tag_name, tag_class)
+
-        yield
+      Environment.dangerously_override(environment, &block)
-      ensure
-        if old_tag
-          Liquid::Template.tags[tag_name] = old_tag
-        else
-          Liquid::Template.tags.delete(tag_name)
-        end
-      end
     end
   end
 end

test/unit/block_unit_test.rb

@@ -32,6 +32,12 @@ class BlockUnitTest < Minitest::Test
     assert_equal(String, template.root.nodelist[2].class)
   end
 
+  def test_variable_with_multibyte_character
+    template = Liquid::Template.parse("{{ '❤️' }}")
+    assert_equal(1, template.root.nodelist.size)
+    assert_equal(Variable, template.root.nodelist[0].class)
+  end
+
   def test_variable_many_embedded_fragments
     template = Liquid::Template.parse("  {{funk}} {{so}} {{brother}} ")
     assert_equal(7, template.root.nodelist.size)

test/unit/condition_unit_test.rb

@@ -55,6 +55,11 @@ class ConditionUnitTest < Minitest::Test
     assert_evaluates_false('bob', 'contains', '---')
   end
 
+  def test_contains_binary_encoding_compatibility_with_utf8
+    assert_evaluates_true('🙈'.b, 'contains', '🙈')
+    assert_evaluates_true('🙈', 'contains', '🙈'.b)
+  end
+
   def test_invalid_comparation_operator
     assert_evaluates_argument_error(1, '~~', 0)
   end
@@ -166,14 +171,14 @@ class ConditionUnitTest < Minitest::Test
   def assert_evaluates_true(left, op, right)
     assert(
       Condition.new(left, op, right).evaluate(@context),
-      "Evaluated false: #{left} #{op} #{right}",
+      "Evaluated false: #{left.inspect} #{op} #{right.inspect}",
     )
   end
 
   def assert_evaluates_false(left, op, right)
     assert(
       !Condition.new(left, op, right).evaluate(@context),
-      "Evaluated true: #{left} #{op} #{right}",
+      "Evaluated true: #{left.inspect} #{op} #{right.inspect}",
     )
   end
 

test/unit/environment_filter_test.rb

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

test/unit/lexer_unit_test.rb

@@ -6,48 +6,144 @@ class LexerUnitTest < Minitest::Test
   include Liquid
 
   def test_strings
-    tokens = Lexer.new(%( 'this is a test""' "wat 'lol'")).tokenize
+    assert_equal(
-    assert_equal([[:string, %('this is a test""')], [:string, %("wat 'lol'")], [:end_of_string]], tokens)
+      [[:string, %('this is a test""')], [:string, %("wat 'lol'")], [:end_of_string]],
+      tokenize(%( 'this is a test""' "wat 'lol'")),
+    )
   end
 
   def test_integer
-    tokens = Lexer.new('hi 50').tokenize
+    assert_equal(
-    assert_equal([[:id, 'hi'], [:number, '50'], [:end_of_string]], tokens)
+      [[:id, 'hi'], [:number, '50'], [:end_of_string]],
+      tokenize('hi 50'),
+    )
   end
 
   def test_float
-    tokens = Lexer.new('hi 5.0').tokenize
+    assert_equal(
-    assert_equal([[:id, 'hi'], [:number, '5.0'], [:end_of_string]], tokens)
+      [[:id, 'hi'], [:number, '5.0'], [:end_of_string]],
+      tokenize('hi 5.0'),
+    )
   end
 
   def test_comparison
-    tokens = Lexer.new('== <> contains ').tokenize
+    assert_equal(
-    assert_equal([[:comparison, '=='], [:comparison, '<>'], [:comparison, 'contains'], [:end_of_string]], tokens)
+      [[:comparison, '=='], [:comparison, '<>'], [:comparison, 'contains'], [:end_of_string]],
+      tokenize('== <> contains '),
+    )
+  end
+
+  def test_comparison_without_whitespace
+    assert_equal(
+      [[:number, '1'], [:comparison, '>'], [:number, '0'], [:end_of_string]],
+      tokenize('1>0'),
+    )
+  end
+
+  def test_comparison_with_negative_number
+    assert_equal(
+      [[:number, '1'], [:comparison, '>'], [:number, '-1'], [:end_of_string]],
+      tokenize('1>-1'),
+    )
+  end
+
+  def test_raise_for_invalid_comparison
+    assert_raises(SyntaxError) do
+      tokenize('1>!1')
+    end
+
+    assert_raises(SyntaxError) do
+      tokenize('1=<1')
+    end
+
+    assert_raises(SyntaxError) do
+      tokenize('1!!1')
+    end
   end
 
   def test_specials
-    tokens = Lexer.new('| .:').tokenize
+    assert_equal(
-    assert_equal([[:pipe, '|'], [:dot, '.'], [:colon, ':'], [:end_of_string]], tokens)
+      [[:pipe, '|'], [:dot, '.'], [:colon, ':'], [:end_of_string]],
-    tokens = Lexer.new('[,]').tokenize
+      tokenize('| .:'),
-    assert_equal([[:open_square, '['], [:comma, ','], [:close_square, ']'], [:end_of_string]], tokens)
+    )
+
+    assert_equal(
+      [[:open_square, '['], [:comma, ','], [:close_square, ']'], [:end_of_string]],
+      tokenize('[,]'),
+    )
   end
 
   def test_fancy_identifiers
-    tokens = Lexer.new('hi five?').tokenize
+    assert_equal([[:id, 'hi'], [:id, 'five?'], [:end_of_string]], tokenize('hi five?'))
-    assert_equal([[:id, 'hi'], [:id, 'five?'], [:end_of_string]], tokens)
 
-    tokens = Lexer.new('2foo').tokenize
+    assert_equal([[:number, '2'], [:id, 'foo'], [:end_of_string]], tokenize('2foo'))
-    assert_equal([[:number, '2'], [:id, 'foo'], [:end_of_string]], tokens)
   end
 
   def test_whitespace
-    tokens = Lexer.new("five|\n\t ==").tokenize
+    assert_equal(
-    assert_equal([[:id, 'five'], [:pipe, '|'], [:comparison, '=='], [:end_of_string]], tokens)
+      [[:id, 'five'], [:pipe, '|'], [:comparison, '=='], [:end_of_string]],
+      tokenize("five|\n\t =="),
+    )
   end
 
   def test_unexpected_character
     assert_raises(SyntaxError) do
-      Lexer.new("%").tokenize
+      tokenize("%")
     end
   end
+
+  def test_negative_numbers
+    assert_equal(
+      [[:id, 'foo'], [:pipe, '|'], [:id, 'default'], [:colon, ":"], [:number, '-1'], [:end_of_string]],
+      tokenize("foo | default: -1"),
+    )
+  end
+
+  def test_greater_than_two_digits
+    assert_equal(
+      [[:id, 'foo'], [:comparison, '>'], [:number, '12'], [:end_of_string]],
+      tokenize("foo > 12"),
+    )
+  end
+
+  def test_error_with_utf8_character
+    error = assert_raises(SyntaxError) do
+      tokenize("1 < 1Ø")
+    end
+
+    assert_equal(
+      'Liquid syntax error: Unexpected character Ø',
+      error.message,
+    )
+  end
+
+  def test_contains_as_attribute_name
+    assert_equal(
+      [[:id, "a"], [:dot, "."], [:id, "contains"], [:dot, "."], [:id, "b"], [:end_of_string]],
+      tokenize("a.contains.b"),
+    )
+  end
+
+  def test_tokenize_incomplete_expression
+    assert_equal([[:id, "false"], [:dash, "-"], [:end_of_string]], tokenize("false -"))
+    assert_equal([[:id, "false"], [:comparison, "<"], [:end_of_string]], tokenize("false <"))
+    assert_equal([[:id, "false"], [:comparison, ">"], [:end_of_string]], tokenize("false >"))
+    assert_equal([[:id, "false"], [:number, "1"], [:end_of_string]], tokenize("false 1"))
+  end
+
+  def test_error_with_invalid_utf8
+    error = assert_raises(SyntaxError) do
+      tokenize("\x00\xff")
+    end
+    assert_equal(
+      'Liquid syntax error: Invalid byte sequence in UTF-8',
+      error.message,
+    )
+  end
+
+  private
+
+  def tokenize(input)
+    Lexer.tokenize(StringScanner.new(input))
+  end
 end

test/unit/parser_unit_test.rb

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

test/unit/strainer_template_unit_test.rb

@@ -25,11 +25,13 @@ class StrainerTemplateUnitTest < Minitest::Test
   end
 
   def test_add_filter_raises_when_module_privately_overrides_registered_public_methods
-    strainer = Context.new.strainer
-
     error = assert_raises(Liquid::MethodOverrideError) do
-      strainer.class.add_filter(PrivateMethodOverrideFilter)
+      Liquid::Environment.build do |env|
+        env.register_filter(PublicMethodOverrideFilter)
+        env.register_filter(PrivateMethodOverrideFilter)
+      end
     end
+
     assert_equal('Liquid error: Filter overrides registered public methods as non public: public_filter', error.message)
   end
 
@@ -42,11 +44,13 @@ class StrainerTemplateUnitTest < Minitest::Test
   end
 
   def test_add_filter_raises_when_module_overrides_registered_public_method_as_protected
-    strainer = Context.new.strainer
-
     error = assert_raises(Liquid::MethodOverrideError) do
-      strainer.class.add_filter(ProtectedMethodOverrideFilter)
+      Liquid::Environment.build do |env|
+        env.register_filter(PublicMethodOverrideFilter)
+        env.register_filter(ProtectedMethodOverrideFilter)
+      end
     end
+
     assert_equal('Liquid error: Filter overrides registered public methods as non public: public_filter', error.message)
   end
 
@@ -58,8 +62,9 @@ class StrainerTemplateUnitTest < Minitest::Test
 
   def test_add_filter_does_not_raise_when_module_overrides_previously_registered_method
     with_global_filter do
-      strainer = Context.new.strainer
+      context = Context.new
-      strainer.class.add_filter(PublicMethodOverrideFilter)
+      context.add_filters([PublicMethodOverrideFilter])
+      strainer = context.strainer
       assert(strainer.class.send(:filter_methods).include?('public_filter'))
     end
   end

test/unit/tag_unit_test.rb

@@ -6,18 +6,36 @@ class TagUnitTest < Minitest::Test
   include Liquid
 
   def test_tag
-    tag = Tag.parse('tag', "", Tokenizer.new(""), ParseContext.new)
+    tag = Tag.parse('tag', "", new_tokenizer, ParseContext.new)
     assert_equal('liquid::tag', tag.name)
     assert_equal('', tag.render(Context.new))
   end
 
   def test_return_raw_text_of_tag
-    tag = Tag.parse("long_tag", "param1, param2, param3", Tokenizer.new(""), ParseContext.new)
+    tag = Tag.parse("long_tag", "param1, param2, param3", new_tokenizer, ParseContext.new)
     assert_equal("long_tag param1, param2, param3", tag.raw)
   end
 
   def test_tag_name_should_return_name_of_the_tag
-    tag = Tag.parse("some_tag", "", Tokenizer.new(""), ParseContext.new)
+    tag = Tag.parse("some_tag", "", new_tokenizer, ParseContext.new)
     assert_equal('some_tag', tag.tag_name)
   end
+
+  class CustomTag < Liquid::Tag
+    def render(_context); end
+  end
+
+  def test_tag_render_to_output_buffer_nil_value
+    custom_tag = CustomTag.parse("some_tag", "", new_tokenizer, ParseContext.new)
+    assert_equal('some string', custom_tag.render_to_output_buffer(Context.new, "some string"))
+  end
+
+  private
+
+  def new_tokenizer
+    Tokenizer.new(
+      source: "",
+      string_scanner: StringScanner.new(""),
+    )
+  end
 end

test/unit/tags/comment_tag_unit_test.rb

@@ -0,0 +1,202 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class CommentTagUnitTest < Minitest::Test
+  def test_comment_inside_liquid_tag
+    assert_template_result("", <<~LIQUID.chomp)
+      {% liquid
+        if 1 != 1
+        comment
+        else
+          echo 123
+        endcomment
+        endif
+      %}
+    LIQUID
+  end
+
+  def test_does_not_parse_nodes_inside_a_comment
+    assert_template_result("", <<~LIQUID.chomp)
+      {% comment %}
+        {% if true %}
+        {% if ... %}
+        {%- for ? -%}
+        {% while true %}
+        {%
+          unless if
+        %}
+        {% endcase %}
+      {% endcomment %}
+    LIQUID
+  end
+
+  def test_allows_unclosed_tags
+    assert_template_result('', <<~LIQUID.chomp)
+      {% comment %}
+        {% if true %}
+      {% endcomment %}
+    LIQUID
+  end
+
+  def test_open_tags_in_comment
+    assert_template_result('', <<~LIQUID.chomp)
+      {% comment %}
+        {% assign a = 123 {% comment %}
+      {% endcomment %}
+    LIQUID
+
+    assert_raises(Liquid::SyntaxError) do
+      assert_template_result("", <<~LIQUID.chomp)
+        {% comment %}
+          {% assign foo = "1"
+        {% endcomment %}
+      LIQUID
+    end
+
+    assert_raises(Liquid::SyntaxError) do
+      assert_template_result("", <<~LIQUID.chomp)
+        {% comment %}
+          {% comment %}
+            {% invalid
+          {% endcomment %}
+        {% endcomment %}
+      LIQUID
+    end
+
+    assert_raises(Liquid::SyntaxError) do
+      assert_template_result("", <<~LIQUID.chomp)
+        {% comment %}
+        {% {{ {%- endcomment %}
+      LIQUID
+    end
+  end
+
+  def test_child_comment_tags_need_to_be_closed
+    assert_template_result("", <<~LIQUID.chomp)
+      {% comment %}
+        {% comment %}
+          {% comment %}{%    endcomment     %}
+        {% endcomment %}
+      {% endcomment %}
+    LIQUID
+
+    assert_raises(Liquid::SyntaxError) do
+      assert_template_result("", <<~LIQUID.chomp)
+        {% comment %}
+          {% comment %}
+            {% comment %}
+          {% endcomment %}
+        {% endcomment %}
+      LIQUID
+    end
+  end
+
+  def test_child_raw_tags_need_to_be_closed
+    assert_template_result("", <<~LIQUID.chomp)
+      {% comment %}
+        {% raw %}
+          {% endcomment %}
+        {% endraw %}
+      {% endcomment %}
+    LIQUID
+
+    assert_raises(Liquid::SyntaxError) do
+      Liquid::Template.parse(<<~LIQUID.chomp)
+        {% comment %}
+          {% raw %}
+          {% endcomment %}
+        {% endcomment %}
+      LIQUID
+    end
+  end
+
+  def test_error_line_number_is_correct
+    template = Liquid::Template.parse(<<~LIQUID.chomp, line_numbers: true)
+      {% comment %}
+        {% if true %}
+      {% endcomment %}
+      {{ errors.standard_error }}
+    LIQUID
+
+    output = template.render('errors' => ErrorDrop.new)
+    expected = <<~TEXT.chomp
+
+      Liquid error (line 4): standard error
+    TEXT
+
+    assert_equal(expected, output)
+  end
+
+  def test_comment_tag_delimiter_with_extra_strings
+    assert_template_result(
+      '',
+      <<~LIQUID.chomp,
+        {% comment %}
+          {% comment %}
+          {% endcomment
+          {% if true %}
+          {% endif %}
+        {% endcomment %}
+      LIQUID
+    )
+  end
+
+  def test_nested_comment_tag_with_extra_strings
+    assert_template_result(
+      '',
+      <<~LIQUID.chomp,
+        {% comment %}
+          {% comment
+            {% assign foo = 1 %}
+          {% endcomment
+          {% assign foo = 1 %}
+        {% endcomment %}
+      LIQUID
+    )
+  end
+
+  def test_ignores_delimiter_with_extra_strings
+    assert_template_result(
+      '',
+      <<~LIQUID.chomp,
+        {% if true %}
+          {% comment %}
+            {% commentXXXXX %}wut{% endcommentXXXXX %}
+          {% endcomment %}
+        {% endif %}
+      LIQUID
+    )
+  end
+
+  def test_delimiter_can_have_extra_strings
+    assert_template_result('', "{% comment %}123{% endcomment xyz %}")
+    assert_template_result('', "{% comment %}123{% endcomment\txyz %}")
+    assert_template_result('', "{% comment %}123{% endcomment\nxyz %}")
+    assert_template_result('', "{% comment %}123{% endcomment\n   xyz  endcomment %}")
+    assert_template_result('', "{%comment}{% assign a = 1 %}{%endcomment}{% endif %}")
+  end
+
+  def test_with_whitespace_control
+    assert_template_result("Hello!", "      {%- comment -%}123{%- endcomment -%}Hello!")
+    assert_template_result("Hello!", "{%- comment -%}123{%- endcomment -%}     Hello!")
+    assert_template_result("Hello!", "      {%- comment -%}123{%- endcomment -%}     Hello!")
+
+    assert_template_result("Hello!", <<~LIQUID.chomp)
+      {%- comment %}Whitespace control!{% endcomment -%}
+      Hello!
+    LIQUID
+  end
+
+  def test_dont_override_liquid_tag_whitespace_control
+    assert_template_result("Hello!World!", <<~LIQUID.chomp)
+      Hello!
+      {%- liquid
+        comment
+         this is inside a liquid tag
+        endcomment
+      -%}
+      World!
+    LIQUID
+  end
+end

test/unit/template_unit_test.rb

@@ -20,62 +20,13 @@ class TemplateUnitTest < Minitest::Test
     assert_equal(fixture("en_locale.yml"), locale.path)
   end
 
-  def test_with_cache_classes_tags_returns_the_same_class
-    original_cache_setting = Liquid.cache_classes
-    Liquid.cache_classes   = true
-
-    original_klass = Class.new
-    Object.send(:const_set, :CustomTag, original_klass)
-    Template.register_tag('custom', CustomTag)
-
-    Object.send(:remove_const, :CustomTag)
-
-    new_klass = Class.new
-    Object.send(:const_set, :CustomTag, new_klass)
-
-    assert(Template.tags['custom'].equal?(original_klass))
-  ensure
-    Object.send(:remove_const, :CustomTag)
-    Template.tags.delete('custom')
-    Liquid.cache_classes = original_cache_setting
-  end
-
-  def test_without_cache_classes_tags_reloads_the_class
-    original_cache_setting = Liquid.cache_classes
-    Liquid.cache_classes   = false
-
-    original_klass = Class.new
-    Object.send(:const_set, :CustomTag, original_klass)
-    Template.register_tag('custom', CustomTag)
-
-    Object.send(:remove_const, :CustomTag)
-
-    new_klass = Class.new
-    Object.send(:const_set, :CustomTag, new_klass)
-
-    assert(Template.tags['custom'].equal?(new_klass))
-  ensure
-    Object.send(:remove_const, :CustomTag)
-    Template.tags.delete('custom')
-    Liquid.cache_classes = original_cache_setting
-  end
-
   class FakeTag; end
 
-  def test_tags_delete
-    Template.register_tag('fake', FakeTag)
-    assert_equal(FakeTag, Template.tags['fake'])
-
-    Template.tags.delete('fake')
-    assert_nil(Template.tags['fake'])
-  end
-
   def test_tags_can_be_looped_over
-    Template.register_tag('fake', FakeTag)
+    with_custom_tag('fake', FakeTag) do
-    result = Template.tags.map { |name, klass| [name, klass] }
+      result = Template.tags.map { |name, klass| [name, klass] }
-    assert(result.include?(["fake", "TemplateUnitTest::FakeTag"]))
+      assert(result.include?(["fake", TemplateUnitTest::FakeTag]))
-  ensure
+    end
-    Template.tags.delete('fake')
   end
 
   class TemplateSubclass < Liquid::Template
@@ -84,4 +35,15 @@ class TemplateUnitTest < Minitest::Test
   def test_template_inheritance
     assert_equal("foo", TemplateSubclass.parse("foo").render)
   end
+
+  def test_invalid_utf8
+    input = "\xff\x00"
+    error = assert_raises(SyntaxError) do
+      Liquid::Tokenizer.new(source: input, string_scanner: StringScanner.new(input))
+    end
+    assert_equal(
+      'Liquid syntax error: Invalid byte sequence in UTF-8',
+      error.message,
+    )
+  end
 end

test/unit/tokenizer_unit_test.rb

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