Refactor the Optimizer class no visit the AST

Just takes care of Variables for now.

Increases performance.

README.md

@@ -80,24 +80,22 @@ It is also recommended that you use it in the template editors of existing apps
 
 By default, the renderer doesn't raise or in any other way notify you if some variables or filters are missing, i.e. not passed to the `render` method.
 You can improve this situation by passing `strict_variables: true` and/or `strict_filters: true` options to the `render` method.
-When one of these options is set to true, all errors about undefined variables and undefined filters will be stored in an `errors` array on the `Liquid::Context` instance used for rendering.
+When one of these options is set to true, all errors about undefined variables and undefined filters will be stored in `errors` array of a `Liquid::Template` instance.
 Here are some examples:
 
 ```ruby
 template = Liquid::Template.parse("{{x}} {{y}} {{z.a}} {{z.b}}")
-context = Liquid::Context.new({ 'x' => 1, 'z' => { 'a' => 2 } })
-template.render(context, { strict_variables: true })
+template.render({ 'x' => 1, 'z' => { 'a' => 2 } }, { strict_variables: true })
 #=> '1  2 ' # when a variable is undefined, it's rendered as nil
-context.errors
+template.errors
 #=> [#<Liquid::UndefinedVariable: Liquid error: undefined variable y>, #<Liquid::UndefinedVariable: Liquid error: undefined variable b>]
 ```
 
 ```ruby
 template = Liquid::Template.parse("{{x | filter1 | upcase}}")
-context = Liquid::Context.new({ 'x' => 'foo' })
-template.render(context, { strict_filters: true })
+template.render({ 'x' => 'foo' }, { strict_filters: true })
 #=> '' # when at least one filter in the filter chain is undefined, a whole expression is rendered as nil
-context.errors
+template.errors
 #=> [#<Liquid::UndefinedFilter: Liquid error: undefined filter filter1>]
 ```
 
@@ -113,4 +111,4 @@ template.render!({ 'x' => 1}, { strict_variables: true })
 
 To help track usages of a feature or code path in production, we have released opt-in usage tracking. To enable this, we provide an empty `Liquid:: Usage.increment` method which you can customize to your needs. The feature is well suited to https://github.com/Shopify/statsd-instrument. However, the choice of implementation is up to you.
 
-Once you have enabled usage tracking, we recommend reporting any events through Github Issues that your system may be logging. It is highly likely this event has been added to consider deprecating or improving code specific to this event, so please raise any concerns.
+Once you have enabled usage tracking, we recommend reporting any events through Github Issues that your system may be logging. It is highly likely this event has been added to consider deprecating or improving code specific to this event, so please raise any concerns.

lib/liquid.rb

@@ -63,6 +63,8 @@ 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'
@@ -82,8 +84,8 @@ require 'liquid/usage'
 require 'liquid/register'
 require 'liquid/static_registers'
 require 'liquid/template_factory'
+require 'liquid/optimizer'
 
 # Load all the tags of the standard library
 #
 Dir["#{__dir__}/liquid/tags/*.rb"].each { |f| require f }
-Dir["#{__dir__}/liquid/registers/*.rb"].each { |f| require f }

lib/liquid/block.rb

@@ -10,7 +10,7 @@ module Liquid
     end
 
     def parse(tokens)
-      @body = BlockBody.new
+      @body = new_body
       while parse_body(@body, tokens)
       end
     end
@@ -28,7 +28,12 @@ module Liquid
       @body.nodelist
     end
 
-    def unknown_tag(tag, _params, _tokens)
+    def unknown_tag(tag_name, _markup, _tokenizer)
+      Block.raise_unknown_tag(tag_name, block_name, block_delimiter, parse_context)
+    end
+
+    # @api private
+    def self.raise_unknown_tag(tag, block_name, block_delimiter, parse_context)
       if tag == 'else'
         raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_else",
           block_name: block_name)
@@ -42,6 +47,10 @@ module Liquid
       end
     end
 
+    def raise_tag_never_closed(block_name)
+      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed", block_name: block_name)
+    end
+
     def block_name
       @tag_name
     end
@@ -50,8 +59,14 @@ module Liquid
       @block_delimiter ||= "end#{block_name}"
     end
 
-    protected
+    private
 
+    # @api public
+    def new_body
+      parse_context.new_block_body
+    end
+
+    # @api public
     def parse_body(body, tokens)
       if parse_context.depth >= MAX_DEPTH
         raise StackLevelError, "Nesting too deep"
@@ -62,9 +77,7 @@ module Liquid
           @blank &&= body.blank?
 
           return false if end_tag_name == block_delimiter
-          unless end_tag_name
-            raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed", block_name: block_name)
-          end
+          raise_tag_never_closed(block_name) unless end_tag_name
 
           # this tag is not registered with the system
           # pass it to the current block for special handling or error reporting

lib/liquid/block_body.rb

@@ -54,28 +54,60 @@ module Liquid
     end
 
     # @api private
-    def self.unknown_tag_in_liquid_tag(end_tag_name, end_tag_markup)
-      yield end_tag_name, end_tag_markup
-    ensure
-      Usage.increment("liquid_tag_contains_outer_tag") unless $ERROR_INFO.is_a?(SyntaxError)
+    def self.unknown_tag_in_liquid_tag(tag, parse_context)
+      Block.raise_unknown_tag(tag, 'liquid', '%}', parse_context)
     end
 
-    private def parse_liquid_tag(markup, parse_context, &block)
-      liquid_tag_tokenizer = Tokenizer.new(markup, line_number: parse_context.line_number, for_liquid_tag: true)
-      parse_for_liquid_tag(liquid_tag_tokenizer, parse_context) do |end_tag_name, end_tag_markup|
-        next unless end_tag_name
-        self.class.unknown_tag_in_liquid_tag(end_tag_name, end_tag_markup, &block)
+    # @api private
+    def self.raise_missing_tag_terminator(token, parse_context)
+      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_termination", token: token, tag_end: TagEnd.inspect)
+    end
+
+    # @api private
+    def self.raise_missing_variable_terminator(token, parse_context)
+      raise SyntaxError, parse_context.locale.t("errors.syntax.variable_termination", token: token, tag_end: VariableEnd.inspect)
+    end
+
+    # @api private
+    def self.render_node(context, output, node)
+      node.render_to_output_buffer(context, output)
+    rescue => exc
+      blank_tag = !node.instance_of?(Variable) && node.blank?
+      rescue_render_node(context, output, node.line_number, exc, blank_tag)
+    end
+
+    # @api private
+    def self.rescue_render_node(context, output, line_number, exc, blank_tag)
+      case exc
+      when MemoryError
+        raise
+      when UndefinedVariable, UndefinedDropMethod, UndefinedFilter
+        context.handle_error(exc, line_number)
+      else
+        error_message = context.handle_error(exc, line_number)
+        unless blank_tag # conditional for backwards compatibility
+          output << error_message
+        end
       end
     end
 
-    private def parse_for_document(tokenizer, parse_context, &block)
+    private def parse_liquid_tag(markup, parse_context)
+      liquid_tag_tokenizer = Tokenizer.new(markup, line_number: parse_context.line_number, for_liquid_tag: true)
+      parse_for_liquid_tag(liquid_tag_tokenizer, parse_context) do |end_tag_name, _end_tag_markup|
+        if end_tag_name
+          BlockBody.unknown_tag_in_liquid_tag(end_tag_name, parse_context)
+        end
+      end
+    end
+
+    private def parse_for_document(tokenizer, parse_context)
       while (token = tokenizer.shift)
         next if token.empty?
         case
         when token.start_with?(TAGSTART)
           whitespace_handler(token, parse_context)
           unless token =~ FullToken
-            raise_missing_tag_terminator(token, parse_context)
+            BlockBody.raise_missing_tag_terminator(token, parse_context)
           end
           tag_name = Regexp.last_match(2)
           markup   = Regexp.last_match(4)
@@ -87,7 +119,7 @@ module Liquid
           end
 
           if tag_name == 'liquid'
-            parse_liquid_tag(markup, parse_context, &block)
+            parse_liquid_tag(markup, parse_context)
             next
           end
 
@@ -121,7 +153,11 @@ module Liquid
       if token[2] == WhitespaceControl
         previous_token = @nodelist.last
         if previous_token.is_a?(String)
+          first_byte = previous_token.getbyte(0)
           previous_token.rstrip!
+          if previous_token.empty? && parse_context[:bug_compatible_whitespace_trimming] && first_byte
+            previous_token << first_byte
+          end
         end
       end
       parse_context.trim_whitespace = (token[-3] == WhitespaceControl)
@@ -131,38 +167,47 @@ module Liquid
       @blank
     end
 
+    # Remove blank strings in the block body for a control flow tag (e.g. `if`, `for`, `case`, `unless`)
+    # with a blank body.
+    #
+    # For example, in a conditional assignment like the following
+    #
+    # ```
+    # {% if size > max_size %}
+    #   {% assign size = max_size %}
+    # {% endif %}
+    # ```
+    #
+    # we assume the intention wasn't to output the blank spaces in the `if` tag's block body, so this method
+    # will remove them to reduce the render output size.
+    #
+    # Note that it is now preferred to use the `liquid` tag for this use case.
+    def remove_blank_strings
+      raise "remove_blank_strings only support being called on a blank block body" unless @blank
+      @nodelist.reject! { |node| node.instance_of?(String) }
+    end
+
     def render(context)
       render_to_output_buffer(context, +'')
     end
 
     def render_to_output_buffer(context, output)
-      context.resource_limits.render_score += @nodelist.length
+      context.resource_limits.increment_render_score(@nodelist.length)
 
       idx = 0
       while (node = @nodelist[idx])
-        previous_output_size = output.bytesize
-
-        case node
-        when String
+        if node.instance_of?(String)
           output << node
-        when Variable
+        else
           render_node(context, output, node)
-        when Block
-          render_node(context, node.blank? ? +'' : output, node)
-          break if context.interrupt? # might have happened in a for-block
-        when Continue, Break
           # If we get an Interrupt that means the block must stop processing. An
           # Interrupt is any command that stops block execution such as {% break %}
-          # or {% continue %}
-          context.push_interrupt(node.interrupt)
-          break
-        else # Other non-Block tags
-          render_node(context, output, node)
-          break if context.interrupt? # might have happened through an include
+          # or {% continue %}. These tags may also occur through Block or Include tags.
+          break if context.interrupt? # might have happened in a for-block
         end
         idx += 1
 
-        raise_if_resource_limits_reached(context, output.bytesize - previous_output_size)
+        context.resource_limits.increment_write_score(output)
       end
 
       output
@@ -171,29 +216,7 @@ module Liquid
     private
 
     def render_node(context, output, node)
-      if node.disabled?(context)
-        output << node.disabled_error_message
-        return
-      end
-      disable_tags(context, node.disabled_tags) do
-        node.render_to_output_buffer(context, output)
-      end
-    rescue UndefinedVariable, UndefinedDropMethod, UndefinedFilter => e
-      context.handle_error(e, node.line_number)
-    rescue ::StandardError => e
-      line_number = node.is_a?(String) ? nil : node.line_number
-      output << context.handle_error(e, line_number)
-    end
-
-    def disable_tags(context, tags, &block)
-      return yield if tags.empty?
-      context.registers[:disabled_tags].disable(tags, &block)
-    end
-
-    def raise_if_resource_limits_reached(context, length)
-      context.resource_limits.render_length += length
-      return unless context.resource_limits.reached?
-      raise MemoryError, "Memory limits exceeded"
+      BlockBody.render_node(context, output, node)
     end
 
     def create_variable(token, parse_context)
@@ -201,15 +224,17 @@ module Liquid
         markup = content.first
         return Variable.new(markup, parse_context)
       end
-      raise_missing_variable_terminator(token, parse_context)
+      BlockBody.raise_missing_variable_terminator(token, parse_context)
     end
 
+    # @deprecated Use {.raise_missing_tag_terminator} instead
     def raise_missing_tag_terminator(token, parse_context)
-      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_termination", token: token, tag_end: TagEnd.inspect)
+      BlockBody.raise_missing_tag_terminator(token, parse_context)
     end
 
+    # @deprecated Use {.raise_missing_variable_terminator} instead
     def raise_missing_variable_terminator(token, parse_context)
-      raise SyntaxError, parse_context.locale.t("errors.syntax.variable_termination", token: token, tag_end: VariableEnd.inspect)
+      BlockBody.raise_missing_variable_terminator(token, parse_context)
     end
 
     def registered_tags

lib/liquid/condition.rb

@@ -27,10 +27,28 @@ module Liquid
       end,
     }
 
+    class MethodLiteral
+      attr_reader :method_name, :to_s
+
+      def initialize(method_name, to_s)
+        @method_name = method_name
+        @to_s = to_s
+      end
+    end
+
+    @@method_literals = {
+      'blank' => MethodLiteral.new(:blank?, '').freeze,
+      'empty' => MethodLiteral.new(:empty?, '').freeze,
+    }
+
     def self.operators
       @@operators
     end
 
+    def self.parse_expression(markup)
+      @@method_literals[markup] || Expression.parse(markup)
+    end
+
     attr_reader :attachment, :child_condition
     attr_accessor :left, :operator, :right
 
@@ -91,7 +109,7 @@ module Liquid
     private
 
     def equal_variables(left, right)
-      if left.is_a?(Liquid::Expression::MethodLiteral)
+      if left.is_a?(MethodLiteral)
         if right.respond_to?(left.method_name)
           return right.send(left.method_name)
         else
@@ -99,7 +117,7 @@ module Liquid
         end
       end
 
-      if right.is_a?(Liquid::Expression::MethodLiteral)
+      if right.is_a?(MethodLiteral)
         if left.respond_to?(right.method_name)
           return left.send(right.method_name)
         else

lib/liquid/context.rb

@@ -34,15 +34,18 @@ module Liquid
       @strict_variables    = false
       @resource_limits     = resource_limits || ResourceLimits.new(Template.default_resource_limits)
       @base_scope_depth    = 0
+      @interrupts          = []
+      @filters             = []
+      @global_filter       = nil
+      @disabled_tags       = {}
 
       self.exception_renderer = Template.default_exception_renderer
       if rethrow_errors
         self.exception_renderer = ->(_e) { raise }
       end
 
-      @interrupts    = []
-      @filters       = []
-      @global_filter = nil
+      # Do this last, since it could result in this object being passed to a Proc in the environment
+      squash_instance_assigns_with_environments
     end
     # rubocop:enable Metrics/ParameterLists
 
@@ -143,6 +146,7 @@ module Liquid
         subcontext.strainer = nil
         subcontext.errors   = errors
         subcontext.warnings = warnings
+        subcontext.disabled_tags = @disabled_tags
       end
     end
 
@@ -207,9 +211,24 @@ module Liquid
       end
     end
 
+    def with_disabled_tags(tag_names)
+      tag_names.each do |name|
+        @disabled_tags[name] = @disabled_tags.fetch(name, 0) + 1
+      end
+      yield
+    ensure
+      tag_names.each do |name|
+        @disabled_tags[name] -= 1
+      end
+    end
+
+    def tag_disabled?(tag_name)
+      @disabled_tags.fetch(tag_name, 0) > 0
+    end
+
     protected
 
-    attr_writer :base_scope_depth, :warnings, :errors, :strainer, :filters
+    attr_writer :base_scope_depth, :warnings, :errors, :strainer, :filters, :disabled_tags
 
     private
 
@@ -245,5 +264,16 @@ module Liquid
     rescue Liquid::InternalError => exc
       exc
     end
+
+    def squash_instance_assigns_with_environments
+      @scopes.last.each_key do |k|
+        @environments.each do |env|
+          if env.key?(k)
+            scopes.last[k] = lookup_and_evaluate(env, k)
+            break
+          end
+        end
+      end
+    end # squash_instance_assigns_with_environments
   end # Context
 end # Liquid

lib/liquid/document.rb

@@ -1,23 +1,33 @@
 # frozen_string_literal: true
 
 module Liquid
-  class Document < BlockBody
+  class Document
     def self.parse(tokens, parse_context)
-      doc = new
+      doc = new(parse_context)
       doc.parse(tokens, parse_context)
       doc
     end
 
-    def parse(tokens, parse_context)
-      super do |end_tag_name, _end_tag_params|
-        unknown_tag(end_tag_name, parse_context) if end_tag_name
+    attr_reader :parse_context, :body
+
+    def initialize(parse_context)
+      @parse_context = parse_context
+      @body = new_body
+    end
+
+    def nodelist
+      @body.nodelist
+    end
+
+    def parse(tokenizer, parse_context)
+      while parse_body(tokenizer)
       end
     rescue SyntaxError => e
       e.line_number ||= parse_context.line_number
       raise
     end
 
-    def unknown_tag(tag, parse_context)
+    def unknown_tag(tag, _markup, _tokenizer)
       case tag
       when 'else', 'end'
         raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_outer_tag", tag: tag)
@@ -25,5 +35,30 @@ module Liquid
         raise SyntaxError, parse_context.locale.t("errors.syntax.unknown_tag", tag: tag)
       end
     end
+
+    def render_to_output_buffer(context, output)
+      @body.render_to_output_buffer(context, output)
+    end
+
+    def render(context)
+      @body.render(context)
+    end
+
+    private
+
+    def new_body
+      parse_context.new_block_body
+    end
+
+    def parse_body(tokenizer)
+      @body.parse(tokenizer, parse_context) do |unknown_tag_name, unknown_tag_markup|
+        if unknown_tag_name
+          unknown_tag(unknown_tag_name, unknown_tag_markup, tokenizer)
+          true
+        else
+          false
+        end
+      end
+    end
   end
 end

lib/liquid/errors.rb

@@ -53,5 +53,6 @@ module Liquid
   UndefinedDropMethod = Class.new(Error)
   UndefinedFilter     = Class.new(Error)
   MethodOverrideError = Class.new(Error)
+  DisabledError       = Class.new(Error)
   InternalError       = Class.new(Error)
 end

lib/liquid/expression.rb

@@ -2,25 +2,12 @@
 
 module Liquid
   class Expression
-    class MethodLiteral
-      attr_reader :method_name, :to_s
-
-      def initialize(method_name, to_s)
-        @method_name = method_name
-        @to_s = to_s
-      end
-
-      def to_liquid
-        to_s
-      end
-    end
-
     LITERALS = {
       nil => nil, 'nil' => nil, 'null' => nil, '' => nil,
       'true' => true,
       'false' => false,
-      'blank' => MethodLiteral.new(:blank?, '').freeze,
-      'empty' => MethodLiteral.new(:empty?, '').freeze
+      'blank' => '',
+      'empty' => ''
     }.freeze
 
     SINGLE_QUOTED_STRING = /\A'(.*)'\z/m

lib/liquid/optimizer.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+module Liquid
+  class Optimizer
+    class << self
+      attr_accessor :enabled
+
+      def optimize_variable(node)
+        return unless enabled
+
+        # Turn chained `| append: "..."| append: "..."`, into a single `append_all: [...]`
+        if node.filters.size > 1 && node.filters.all? { |f, _| f == "append" }
+          node.filters = [["append_all", node.filters.map { |f, (arg)| arg }]]
+        end
+      end
+    end
+    self.enabled = true
+  end
+end

lib/liquid/parse_context.rb

@@ -19,6 +19,10 @@ module Liquid
       @options[option_key]
     end
 
+    def new_block_body
+      Liquid::BlockBody.new
+    end
+
     def partial=(value)
       @partial = value
       @options = value ? partial_options : @template_options

lib/liquid/profiler/hooks.rb

@@ -1,25 +1,21 @@
 # frozen_string_literal: true
 
 module Liquid
-  class BlockBody
-    def render_node_with_profiling(context, output, node)
+  module BlockBodyProfilingHook
+    def render_node(context, output, node)
       Profiler.profile_node_render(node) do
-        render_node_without_profiling(context, output, node)
+        super
       end
     end
-
-    alias_method :render_node_without_profiling, :render_node
-    alias_method :render_node, :render_node_with_profiling
   end
+  BlockBody.prepend(BlockBodyProfilingHook)
 
-  class Include < Tag
-    def render_to_output_buffer_with_profiling(context, output)
+  module IncludeProfilingHook
+    def render_to_output_buffer(context, output)
       Profiler.profile_children(context.evaluate(@template_name_expr).to_s) do
-        render_to_output_buffer_without_profiling(context, output)
+        super
       end
     end
-
-    alias_method :render_to_output_buffer_without_profiling, :render_to_output_buffer
-    alias_method :render_to_output_buffer, :render_to_output_buffer_with_profiling
   end
+  Include.prepend(IncludeProfilingHook)
 end

lib/liquid/registers/disabled_tags.rb

@@ -1,32 +0,0 @@
-# frozen_string_literal: true
-module Liquid
-  class DisabledTags < Register
-    def initialize
-      @disabled_tags = {}
-    end
-
-    def disabled?(tag)
-      @disabled_tags.key?(tag) && @disabled_tags[tag] > 0
-    end
-
-    def disable(tags)
-      tags.each(&method(:increment))
-      yield
-    ensure
-      tags.each(&method(:decrement))
-    end
-
-    private
-
-    def increment(tag)
-      @disabled_tags[tag] ||= 0
-      @disabled_tags[tag]  += 1
-    end
-
-    def decrement(tag)
-      @disabled_tags[tag] -= 1
-    end
-  end
-
-  Template.add_register(:disabled_tags, DisabledTags.new)
-end

lib/liquid/resource_limits.rb

@@ -2,8 +2,8 @@
 
 module Liquid
   class ResourceLimits
-    attr_accessor :render_length, :render_score, :assign_score,
-      :render_length_limit, :render_score_limit, :assign_score_limit
+    attr_accessor :render_length_limit, :render_score_limit, :assign_score_limit
+    attr_reader :render_score, :assign_score
 
     def initialize(limits)
       @render_length_limit = limits[:render_length_limit]
@@ -12,14 +12,51 @@ module Liquid
       reset
     end
 
+    def increment_render_score(amount)
+      @render_score += amount
+      raise_limits_reached if @render_score_limit && @render_score > @render_score_limit
+    end
+
+    def increment_assign_score(amount)
+      @assign_score += amount
+      raise_limits_reached if @assign_score_limit && @assign_score > @assign_score_limit
+    end
+
+    # update either render_length or assign_score based on whether or not the writes are captured
+    def increment_write_score(output)
+      if (last_captured = @last_capture_length)
+        captured = output.bytesize
+        increment = captured - last_captured
+        @last_capture_length = captured
+        increment_assign_score(increment)
+      elsif @render_length_limit && output.bytesize > @render_length_limit
+        raise_limits_reached
+      end
+    end
+
+    def raise_limits_reached
+      @reached_limit = true
+      raise MemoryError, "Memory limits exceeded"
+    end
+
     def reached?
-      (@render_length_limit && @render_length > @render_length_limit) ||
-        (@render_score_limit && @render_score > @render_score_limit) ||
-        (@assign_score_limit && @assign_score > @assign_score_limit)
+      @reached_limit
     end
 
     def reset
-      @render_length = @render_score = @assign_score = 0
+      @reached_limit = false
+      @last_capture_length = nil
+      @render_score = @assign_score = 0
+    end
+
+    def with_capture
+      old_capture_length = @last_capture_length
+      begin
+        @last_capture_length = 0
+        yield
+      ensure
+        @last_capture_length = old_capture_length
+      end
     end
   end
 end

lib/liquid/standardfilters.rb

@@ -281,6 +281,10 @@ module Liquid
       input.to_s + string.to_s
     end
 
+    def append_all(input, *items)
+      input.to_s + items.join
+    end
+
     def concat(input, array)
       unless array.respond_to?(:to_ary)
         raise ArgumentError, "concat filter requires an array argument"

lib/liquid/tag.rb

@@ -13,15 +13,13 @@ module Liquid
         tag
       end
 
-      def disable_tags(*tags)
-        disabled_tags.push(*tags)
+      def disable_tags(*tag_names)
+        @disabled_tags ||= []
+        @disabled_tags.concat(tag_names)
+        prepend(Disabler)
       end
 
       private :new
-
-      def disabled_tags
-        @disabled_tags ||= []
-      end
     end
 
     def initialize(tag_name, markup, parse_context)
@@ -46,14 +44,6 @@ module Liquid
       ''
     end
 
-    def disabled?(context)
-      context.registers[:disabled_tags].disabled?(tag_name)
-    end
-
-    def disabled_error_message
-      "#{tag_name} #{options[:locale].t('errors.disabled.tag')}"
-    end
-
     # For backwards compatibility with custom tags. In a future release, the semantics
     # of the `render_to_output_buffer` method will become the default and the `render`
     # method will be removed.
@@ -65,9 +55,5 @@ module Liquid
     def blank?
       false
     end
-
-    def disabled_tags
-      self.class.disabled_tags
-    end
   end
 end

lib/liquid/tag/disableable.rb

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

lib/liquid/tag/disabler.rb

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

lib/liquid/tags/assign.rb

@@ -27,7 +27,7 @@ module Liquid
     def render_to_output_buffer(context, output)
       val = @from.render(context)
       context.scopes.last[@to] = val
-      context.resource_limits.assign_score += assign_score_of(val)
+      context.resource_limits.increment_assign_score(assign_score_of(val))
       output
     end
 

lib/liquid/tags/break.rb

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

lib/liquid/tags/capture.rb

@@ -25,10 +25,10 @@ module Liquid
     end
 
     def render_to_output_buffer(context, output)
-      previous_output_size = output.bytesize
-      super
-      context.scopes.last[@to] = output
-      context.resource_limits.assign_score += (output.bytesize - previous_output_size)
+      context.resource_limits.with_capture do
+        capture_output = render(context)
+        context.scopes.last[@to] = capture_output
+      end
       output
     end
 

lib/liquid/tags/case.rb

@@ -19,8 +19,11 @@ module Liquid
     end
 
     def parse(tokens)
-      body = BlockBody.new
+      body = new_body
       body = @blocks.last.attachment while parse_body(body, tokens)
+      if blank?
+        @blocks.each { |condition| condition.attachment.remove_blank_strings }
+      end
     end
 
     def nodelist
@@ -56,7 +59,7 @@ module Liquid
     private
 
     def record_when_condition(markup)
-      body = BlockBody.new
+      body = new_body
 
       while markup
         unless markup =~ WhenSyntax
@@ -65,7 +68,7 @@ module Liquid
 
         markup = Regexp.last_match(2)
 
-        block = Condition.new(@left, '==', Expression.parse(Regexp.last_match(1)))
+        block = Condition.new(@left, '==', Condition.parse_expression(Regexp.last_match(1)))
         block.attach(body)
         @blocks << block
       end
@@ -77,7 +80,7 @@ module Liquid
       end
 
       block = ElseCondition.new
-      block.attach(BlockBody.new)
+      block.attach(new_body)
       @blocks << block
     end
 

lib/liquid/tags/continue.rb

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

lib/liquid/tags/for.rb

@@ -54,13 +54,18 @@ module Liquid
       super
       @from = @limit = nil
       parse_with_selected_parser(markup)
-      @for_block = BlockBody.new
+      @for_block = new_body
       @else_block = nil
     end
 
     def parse(tokens)
-      return unless parse_body(@for_block, tokens)
-      parse_body(@else_block, tokens)
+      if parse_body(@for_block, tokens)
+        parse_body(@else_block, tokens)
+      end
+      if blank?
+        @for_block.remove_blank_strings
+        @else_block&.remove_blank_strings
+      end
     end
 
     def nodelist
@@ -69,7 +74,7 @@ module Liquid
 
     def unknown_tag(tag, markup, tokens)
       return super unless tag == 'else'
-      @else_block = BlockBody.new
+      @else_block = new_body
     end
 
     def render_to_output_buffer(context, output)

lib/liquid/tags/if.rb

@@ -31,6 +31,9 @@ module Liquid
     def parse(tokens)
       while parse_body(@blocks.last.attachment, tokens)
       end
+      if blank?
+        @blocks.each { |condition| condition.attachment.remove_blank_strings }
+      end
     end
 
     def unknown_tag(tag, markup, tokens)
@@ -61,21 +64,25 @@ module Liquid
       end
 
       @blocks.push(block)
-      block.attach(BlockBody.new)
+      block.attach(new_body)
+    end
+
+    def parse_expression(markup)
+      Condition.parse_expression(markup)
     end
 
     def lax_parse(markup)
       expressions = markup.scan(ExpressionsAndOperators)
       raise SyntaxError, options[:locale].t("errors.syntax.if") unless expressions.pop =~ Syntax
 
-      condition = Condition.new(Expression.parse(Regexp.last_match(1)), Regexp.last_match(2), Expression.parse(Regexp.last_match(3)))
+      condition = Condition.new(parse_expression(Regexp.last_match(1)), Regexp.last_match(2), parse_expression(Regexp.last_match(3)))
 
       until expressions.empty?
         operator = expressions.pop.to_s.strip
 
         raise SyntaxError, options[:locale].t("errors.syntax.if") unless expressions.pop.to_s =~ Syntax
 
-        new_condition = Condition.new(Expression.parse(Regexp.last_match(1)), Regexp.last_match(2), Expression.parse(Regexp.last_match(3)))
+        new_condition = Condition.new(parse_expression(Regexp.last_match(1)), Regexp.last_match(2), parse_expression(Regexp.last_match(3)))
         raise SyntaxError, options[:locale].t("errors.syntax.if") unless BOOLEAN_OPERATORS.include?(operator)
         new_condition.send(operator, condition)
         condition = new_condition
@@ -103,9 +110,9 @@ module Liquid
     end
 
     def parse_comparison(p)
-      a = Expression.parse(p.expression)
+      a = parse_expression(p.expression)
       if (op = p.consume?(:comparison))
-        b = Expression.parse(p.expression)
+        b = parse_expression(p.expression)
         Condition.new(a, op, b)
       else
         Condition.new(a)

lib/liquid/tags/include.rb

@@ -16,6 +16,8 @@ module Liquid
   #   {% include 'product' for products %}
   #
   class Include < Tag
+    prepend Tag::Disableable
+
     SYNTAX = /(#{QuotedFragment}+)(\s+(?:with|for)\s+(#{QuotedFragment}+))?(\s+(?:as)\s+(#{VariableSegment}+))?/o
     Syntax = SYNTAX
 

lib/liquid/tags/raw.rb

@@ -14,14 +14,14 @@ module Liquid
     def parse(tokens)
       @body = +''
       while (token = tokens.shift)
-        if token =~ FullTokenPossiblyInvalid
+        if token =~ FullTokenPossiblyInvalid && block_delimiter == Regexp.last_match(2)
           @body << Regexp.last_match(1) if Regexp.last_match(1) != ""
-          return if block_delimiter == Regexp.last_match(2)
+          return
         end
         @body << token unless token.empty?
       end
 
-      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed", block_name: block_name)
+      raise_tag_never_closed(block_name)
     end
 
     def render_to_output_buffer(_context, output)

lib/liquid/template.rb

@@ -16,7 +16,7 @@ module Liquid
   #
   class Template
     attr_accessor :root
-    attr_reader :warnings
+    attr_reader :resource_limits, :warnings
 
     class TagRegistry
       include Enumerable
@@ -80,14 +80,6 @@ module Liquid
         tags[name.to_s] = klass
       end
 
-      attr_accessor :registers
-      Template.registers = {}
-      private :registers=
-
-      def add_register(name, klass)
-        registers[name.to_sym] = 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)
@@ -106,6 +98,11 @@ module Liquid
       end
     end
 
+    def initialize
+      @rethrow_errors  = false
+      @resource_limits = ResourceLimits.new(Template.default_resource_limits)
+    end
+
     # Parse source code.
     # Returns self for easy chaining
     def parse(source, options = {})
@@ -118,6 +115,22 @@ module Liquid
       self
     end
 
+    def registers
+      @registers ||= {}
+    end
+
+    def assigns
+      @assigns ||= {}
+    end
+
+    def instance_assigns
+      @instance_assigns ||= {}
+    end
+
+    def errors
+      @errors ||= []
+    end
+
     # Render takes a hash with local variables.
     #
     # if you use the same filters over and over again consider registering them globally
@@ -132,18 +145,37 @@ module Liquid
     #  * <tt>registers</tt> : hash with register variables. Those can be accessed from
     #    filters and tags and might be useful to integrate liquid more with its host application
     #
-    def render(assigns_or_context = nil, options = nil)
+    def render(*args)
       return '' if @root.nil?
 
-      context = coerce_context(assigns_or_context)
+      context = case args.first
+      when Liquid::Context
+        c = args.shift
+
+        if @rethrow_errors
+          c.exception_renderer = ->(_e) { raise }
+        end
+
+        c
+      when Liquid::Drop
+        drop         = args.shift
+        drop.context = Context.new([drop, assigns], instance_assigns, registers, @rethrow_errors, @resource_limits)
+      when Hash
+        Context.new([args.shift, assigns], instance_assigns, registers, @rethrow_errors, @resource_limits)
+      when nil
+        Context.new(assigns, instance_assigns, registers, @rethrow_errors, @resource_limits)
+      else
+        raise ArgumentError, "Expected Hash or Liquid::Context as parameter"
+      end
 
       output = nil
 
       context_register = context.registers.is_a?(StaticRegisters) ? context.registers.static : context.registers
 
-      case options
+      case args.last
       when Hash
-        output = options[:output] if options[:output]
+        options = args.pop
+        output  = options[:output] if options[:output]
 
         options[:registers]&.each do |key, register|
           context_register[key] = register
@@ -151,11 +183,7 @@ module Liquid
 
         apply_options_to_context(context, options)
       when Module, Array
-        context.add_filters(options)
-      end
-
-      Template.registers.each do |key, register|
-        context_register[key] = register unless context_register.key?(key)
+        context.add_filters(args.pop)
       end
 
       # Retrying a render resets resource usage
@@ -169,15 +197,14 @@ module Liquid
         end
       rescue Liquid::MemoryError => e
         context.handle_error(e)
+      ensure
+        @errors = context.errors
       end
     end
 
-    def render!(assigns_or_context = nil, options = nil)
-      context = coerce_context(assigns_or_context)
-      # rethrow errors
-      context.exception_renderer = ->(_e) { raise }
-
-      render(context, options)
+    def render!(*args)
+      @rethrow_errors = true
+      render(*args)
     end
 
     def render_to_output_buffer(context, output)
@@ -186,22 +213,6 @@ module Liquid
 
     private
 
-    def coerce_context(assigns_or_context)
-      case assigns_or_context
-      when Liquid::Context
-        assigns_or_context
-      when Liquid::Drop
-        drop = assigns_or_context
-        drop.context = Context.build(environments: [drop])
-      when Hash
-        Context.build(environments: [assigns_or_context])
-      when nil
-        Context.build
-      else
-        raise ArgumentError, "Expected Hash or Liquid::Context as parameter"
-      end
-    end
-
     def tokenize(source)
       Tokenizer.new(source, @line_numbers)
     end

lib/liquid/variable.rb

@@ -31,6 +31,8 @@ module Liquid
       @line_number   = parse_context.line_number
 
       parse_with_selected_parser(markup)
+
+      Optimizer.optimize_variable(self)
     end
 
     def raw

performance/theme_runner.rb

@@ -73,29 +73,26 @@ class ThemeRunner
 
   private
 
-  def compile_and_render(template, layout, assigns, page_template)
-    assigns = assigns.merge(
-      'page_title' => 'Page title',
-      'template' => page_template,
-    )
-    compiled_test = compile_test(template, layout, assigns)
+  def compile_and_render(template, layout, assigns, page_template, template_file)
+    compiled_test                 = compile_test(template, layout, assigns, page_template, template_file)
     assigns['content_for_layout'] = compiled_test[:tmpl].render!(assigns)
     compiled_test[:layout].render!(assigns) if layout
   end
 
   def compile_all_tests
     @compiled_tests = []
-    each_test do |liquid, layout, assigns, _page_template, _template_name|
-      @compiled_tests << compile_test(liquid, layout, assigns)
+    each_test do |liquid, layout, assigns, page_template, template_name|
+      @compiled_tests << compile_test(liquid, layout, assigns, page_template, template_name)
     end
     @compiled_tests
   end
 
-  def compile_test(template, layout, assigns)
-    parsed_template = Liquid::Template.parse(template).dup
+  def compile_test(template, layout, assigns, page_template, template_file)
+    tmpl            = init_template(page_template, template_file)
+    parsed_template = tmpl.parse(template).dup
 
     if layout
-      parsed_layout = Liquid::Template.parse(layout)
+      parsed_layout = tmpl.parse(layout)
       { tmpl: parsed_template, assigns: assigns, layout: parsed_layout }
     else
       { tmpl: parsed_template, assigns: assigns }
@@ -110,7 +107,16 @@ class ThemeRunner
     @tests.each do |test_hash|
       # Compute page_template outside of profiler run, uninteresting to profiler
       page_template = File.basename(test_hash[:template_name], File.extname(test_hash[:template_name]))
-      yield(test_hash[:liquid], test_hash[:layout], assigns, page_template)
+      yield(test_hash[:liquid], test_hash[:layout], assigns, page_template, test_hash[:template_name])
     end
   end
+
+  # set up a new Liquid::Template object for use in `compile_and_render` and `compile_test`
+  def init_template(page_template, template_file)
+    tmpl                         = Liquid::Template.new
+    tmpl.assigns['page_title']   = 'Page title'
+    tmpl.assigns['template']     = page_template
+    tmpl.registers[:file_system] = ThemeRunner::FileSystem.new(File.dirname(template_file))
+    tmpl
+  end
 end

test/integration/block_test.rb

@@ -11,4 +11,48 @@ class BlockTest < Minitest::Test
     end
     assert_equal(exc.message, "Liquid syntax error: 'endunless' is not a valid delimiter for if tags. use endif")
   end
+
+  def test_with_custom_tag
+    with_custom_tag('testtag', Block) do
+      assert Liquid::Template.parse("{% testtag %} {% endtesttag %}")
+    end
+  end
+
+  def test_custom_block_tags_have_a_default_render_to_output_buffer_method_for_backwards_compatibility
+    klass1 = Class.new(Block) do
+      def render(*)
+        'hello'
+      end
+    end
+
+    with_custom_tag('blabla', klass1) do
+      template = Liquid::Template.parse("{% blabla %} bla {% endblabla %}")
+
+      assert_equal 'hello', template.render
+
+      buf    = +''
+      output = template.render({}, output: buf)
+      assert_equal 'hello', output
+      assert_equal 'hello', buf
+      assert_equal buf.object_id, output.object_id
+    end
+
+    klass2 = Class.new(klass1) do
+      def render(*)
+        'foo' + super + 'bar'
+      end
+    end
+
+    with_custom_tag('blabla', klass2) do
+      template = Liquid::Template.parse("{% blabla %} foo {% endblabla %}")
+
+      assert_equal 'foohellobar', template.render
+
+      buf    = +''
+      output = template.render({}, output: buf)
+      assert_equal 'foohellobar', output
+      assert_equal 'foohellobar', buf
+      assert_equal buf.object_id, output.object_id
+    end
+  end
 end

test/integration/context_test

@@ -65,7 +65,7 @@ class ArrayLike
   end
 end
 
-class ContextUnitTest < Minitest::Test
+class ContextTest < Minitest::Test
   include Liquid
 
   def setup
@@ -563,6 +563,35 @@ class ContextUnitTest < Minitest::Test
     assert_equal('my filter result', template.render(subcontext))
   end
 
+  def test_disables_tag_specified
+    context = Context.new
+    context.with_disabled_tags(%w(foo bar)) do
+      assert_equal true, context.tag_disabled?("foo")
+      assert_equal true, context.tag_disabled?("bar")
+      assert_equal false, context.tag_disabled?("unknown")
+    end
+  end
+
+  def test_disables_nested_tags
+    context = Context.new
+    context.with_disabled_tags(["foo"]) do
+      context.with_disabled_tags(["foo"]) do
+        assert_equal true, context.tag_disabled?("foo")
+        assert_equal false, context.tag_disabled?("bar")
+      end
+      context.with_disabled_tags(["bar"]) do
+        assert_equal true, context.tag_disabled?("foo")
+        assert_equal true, context.tag_disabled?("bar")
+        context.with_disabled_tags(["foo"]) do
+          assert_equal true, context.tag_disabled?("foo")
+          assert_equal true, context.tag_disabled?("bar")
+        end
+      end
+      assert_equal true, context.tag_disabled?("foo")
+      assert_equal false, context.tag_disabled?("bar")
+    end
+  end
+
   private
 
   def assert_no_object_allocations

test/integration/context_test.rb

@@ -2,9 +2,596 @@
 
 require 'test_helper'
 
+class HundredCentes
+  def to_liquid
+    100
+  end
+end
+
+class CentsDrop < Liquid::Drop
+  def amount
+    HundredCentes.new
+  end
+
+  def non_zero?
+    true
+  end
+end
+
+class ContextSensitiveDrop < Liquid::Drop
+  def test
+    @context['test']
+  end
+end
+
+class Category < Liquid::Drop
+  attr_accessor :name
+
+  def initialize(name)
+    @name = name
+  end
+
+  def to_liquid
+    CategoryDrop.new(self)
+  end
+end
+
+class CategoryDrop
+  attr_accessor :category, :context
+  def initialize(category)
+    @category = category
+  end
+end
+
+class CounterDrop < Liquid::Drop
+  def count
+    @count ||= 0
+    @count  += 1
+  end
+end
+
+class ArrayLike
+  def fetch(index)
+  end
+
+  def [](index)
+    @counts        ||= []
+    @counts[index] ||= 0
+    @counts[index]  += 1
+  end
+
+  def to_liquid
+    self
+  end
+end
+
 class ContextTest < Minitest::Test
   include Liquid
 
+  def setup
+    @context = Liquid::Context.new
+  end
+
+  def test_variables
+    @context['string'] = 'string'
+    assert_equal('string', @context['string'])
+
+    @context['num'] = 5
+    assert_equal(5, @context['num'])
+
+    @context['time'] = Time.parse('2006-06-06 12:00:00')
+    assert_equal(Time.parse('2006-06-06 12:00:00'), @context['time'])
+
+    @context['date'] = Date.today
+    assert_equal(Date.today, @context['date'])
+
+    now = Time.now
+    @context['datetime'] = now
+    assert_equal(now, @context['datetime'])
+
+    @context['bool'] = true
+    assert_equal(true, @context['bool'])
+
+    @context['bool'] = false
+    assert_equal(false, @context['bool'])
+
+    @context['nil'] = nil
+    assert_nil(@context['nil'])
+    assert_nil(@context['nil'])
+  end
+
+  def test_variables_not_existing
+    assert_nil(@context['does_not_exist'])
+  end
+
+  def test_scoping
+    @context.push
+    @context.pop
+
+    assert_raises(Liquid::ContextError) do
+      @context.pop
+    end
+
+    assert_raises(Liquid::ContextError) do
+      @context.push
+      @context.pop
+      @context.pop
+    end
+  end
+
+  def test_length_query
+    @context['numbers'] = [1, 2, 3, 4]
+
+    assert_equal(4, @context['numbers.size'])
+
+    @context['numbers'] = { 1 => 1, 2 => 2, 3 => 3, 4 => 4 }
+
+    assert_equal(4, @context['numbers.size'])
+
+    @context['numbers'] = { 1 => 1, 2 => 2, 3 => 3, 4 => 4, 'size' => 1000 }
+
+    assert_equal(1000, @context['numbers.size'])
+  end
+
+  def test_hyphenated_variable
+    @context['oh-my'] = 'godz'
+    assert_equal('godz', @context['oh-my'])
+  end
+
+  def test_add_filter
+    filter = Module.new do
+      def hi(output)
+        output + ' hi!'
+      end
+    end
+
+    context = Context.new
+    context.add_filters(filter)
+    assert_equal('hi? hi!', context.invoke(:hi, 'hi?'))
+
+    context = Context.new
+    assert_equal('hi?', context.invoke(:hi, 'hi?'))
+
+    context.add_filters(filter)
+    assert_equal('hi? hi!', context.invoke(:hi, 'hi?'))
+  end
+
+  def test_only_intended_filters_make_it_there
+    filter = Module.new do
+      def hi(output)
+        output + ' hi!'
+      end
+    end
+
+    context = Context.new
+    assert_equal("Wookie", context.invoke("hi", "Wookie"))
+
+    context.add_filters(filter)
+    assert_equal("Wookie hi!", context.invoke("hi", "Wookie"))
+  end
+
+  def test_add_item_in_outer_scope
+    @context['test'] = 'test'
+    @context.push
+    assert_equal('test', @context['test'])
+    @context.pop
+    assert_equal('test', @context['test'])
+  end
+
+  def test_add_item_in_inner_scope
+    @context.push
+    @context['test'] = 'test'
+    assert_equal('test', @context['test'])
+    @context.pop
+    assert_nil(@context['test'])
+  end
+
+  def test_hierachical_data
+    @context['hash'] = { "name" => 'tobi' }
+    assert_equal('tobi', @context['hash.name'])
+    assert_equal('tobi', @context['hash["name"]'])
+  end
+
+  def test_keywords
+    assert_equal(true, @context['true'])
+    assert_equal(false, @context['false'])
+  end
+
+  def test_digits
+    assert_equal(100, @context['100'])
+    assert_equal(100.00, @context['100.00'])
+  end
+
+  def test_strings
+    assert_equal("hello!", @context['"hello!"'])
+    assert_equal("hello!", @context["'hello!'"])
+  end
+
+  def test_merge
+    @context.merge("test" => "test")
+    assert_equal('test', @context['test'])
+    @context.merge("test" => "newvalue", "foo" => "bar")
+    assert_equal('newvalue', @context['test'])
+    assert_equal('bar', @context['foo'])
+  end
+
+  def test_array_notation
+    @context['test'] = [1, 2, 3, 4, 5]
+
+    assert_equal(1, @context['test[0]'])
+    assert_equal(2, @context['test[1]'])
+    assert_equal(3, @context['test[2]'])
+    assert_equal(4, @context['test[3]'])
+    assert_equal(5, @context['test[4]'])
+  end
+
+  def test_recoursive_array_notation
+    @context['test'] = { 'test' => [1, 2, 3, 4, 5] }
+
+    assert_equal(1, @context['test.test[0]'])
+
+    @context['test'] = [{ 'test' => 'worked' }]
+
+    assert_equal('worked', @context['test[0].test'])
+  end
+
+  def test_hash_to_array_transition
+    @context['colors'] = {
+      'Blue' => ['003366', '336699', '6699CC', '99CCFF'],
+      'Green' => ['003300', '336633', '669966', '99CC99'],
+      'Yellow' => ['CC9900', 'FFCC00', 'FFFF99', 'FFFFCC'],
+      'Red' => ['660000', '993333', 'CC6666', 'FF9999'],
+    }
+
+    assert_equal('003366', @context['colors.Blue[0]'])
+    assert_equal('FF9999', @context['colors.Red[3]'])
+  end
+
+  def test_try_first
+    @context['test'] = [1, 2, 3, 4, 5]
+
+    assert_equal(1, @context['test.first'])
+    assert_equal(5, @context['test.last'])
+
+    @context['test'] = { 'test' => [1, 2, 3, 4, 5] }
+
+    assert_equal(1, @context['test.test.first'])
+    assert_equal(5, @context['test.test.last'])
+
+    @context['test'] = [1]
+    assert_equal(1, @context['test.first'])
+    assert_equal(1, @context['test.last'])
+  end
+
+  def test_access_hashes_with_hash_notation
+    @context['products'] = { 'count' => 5, 'tags' => ['deepsnow', 'freestyle'] }
+    @context['product']  = { 'variants' => [{ 'title' => 'draft151cm' }, { 'title' => 'element151cm' }] }
+
+    assert_equal(5, @context['products["count"]'])
+    assert_equal('deepsnow', @context['products["tags"][0]'])
+    assert_equal('deepsnow', @context['products["tags"].first'])
+    assert_equal('draft151cm', @context['product["variants"][0]["title"]'])
+    assert_equal('element151cm', @context['product["variants"][1]["title"]'])
+    assert_equal('draft151cm', @context['product["variants"][0]["title"]'])
+    assert_equal('element151cm', @context['product["variants"].last["title"]'])
+  end
+
+  def test_access_variable_with_hash_notation
+    @context['foo'] = 'baz'
+    @context['bar'] = 'foo'
+
+    assert_equal('baz', @context['["foo"]'])
+    assert_equal('baz', @context['[bar]'])
+  end
+
+  def test_access_hashes_with_hash_access_variables
+    @context['var']      = 'tags'
+    @context['nested']   = { 'var' => 'tags' }
+    @context['products'] = { 'count' => 5, 'tags' => ['deepsnow', 'freestyle'] }
+
+    assert_equal('deepsnow', @context['products[var].first'])
+    assert_equal('freestyle', @context['products[nested.var].last'])
+  end
+
+  def test_hash_notation_only_for_hash_access
+    @context['array'] = [1, 2, 3, 4, 5]
+    @context['hash']  = { 'first' => 'Hello' }
+
+    assert_equal(1, @context['array.first'])
+    assert_nil(@context['array["first"]'])
+    assert_equal('Hello', @context['hash["first"]'])
+  end
+
+  def test_first_can_appear_in_middle_of_callchain
+    @context['product'] = { 'variants' => [{ 'title' => 'draft151cm' }, { 'title' => 'element151cm' }] }
+
+    assert_equal('draft151cm', @context['product.variants[0].title'])
+    assert_equal('element151cm', @context['product.variants[1].title'])
+    assert_equal('draft151cm', @context['product.variants.first.title'])
+    assert_equal('element151cm', @context['product.variants.last.title'])
+  end
+
+  def test_cents
+    @context.merge("cents" => HundredCentes.new)
+    assert_equal(100, @context['cents'])
+  end
+
+  def test_nested_cents
+    @context.merge("cents" => { 'amount' => HundredCentes.new })
+    assert_equal(100, @context['cents.amount'])
+
+    @context.merge("cents" => { 'cents' => { 'amount' => HundredCentes.new } })
+    assert_equal(100, @context['cents.cents.amount'])
+  end
+
+  def test_cents_through_drop
+    @context.merge("cents" => CentsDrop.new)
+    assert_equal(100, @context['cents.amount'])
+  end
+
+  def test_nested_cents_through_drop
+    @context.merge("vars" => { "cents" => CentsDrop.new })
+    assert_equal(100, @context['vars.cents.amount'])
+  end
+
+  def test_drop_methods_with_question_marks
+    @context.merge("cents" => CentsDrop.new)
+    assert(@context['cents.non_zero?'])
+  end
+
+  def test_context_from_within_drop
+    @context.merge("test" => '123', "vars" => ContextSensitiveDrop.new)
+    assert_equal('123', @context['vars.test'])
+  end
+
+  def test_nested_context_from_within_drop
+    @context.merge("test" => '123', "vars" => { "local" => ContextSensitiveDrop.new })
+    assert_equal('123', @context['vars.local.test'])
+  end
+
+  def test_ranges
+    @context.merge("test" => '5')
+    assert_equal((1..5), @context['(1..5)'])
+    assert_equal((1..5), @context['(1..test)'])
+    assert_equal((5..5), @context['(test..test)'])
+  end
+
+  def test_cents_through_drop_nestedly
+    @context.merge("cents" => { "cents" => CentsDrop.new })
+    assert_equal(100, @context['cents.cents.amount'])
+
+    @context.merge("cents" => { "cents" => { "cents" => CentsDrop.new } })
+    assert_equal(100, @context['cents.cents.cents.amount'])
+  end
+
+  def test_drop_with_variable_called_only_once
+    @context['counter'] = CounterDrop.new
+
+    assert_equal(1, @context['counter.count'])
+    assert_equal(2, @context['counter.count'])
+    assert_equal(3, @context['counter.count'])
+  end
+
+  def test_drop_with_key_called_only_once
+    @context['counter'] = CounterDrop.new
+
+    assert_equal(1, @context['counter["count"]'])
+    assert_equal(2, @context['counter["count"]'])
+    assert_equal(3, @context['counter["count"]'])
+  end
+
+  def test_proc_as_variable
+    @context['dynamic'] = proc { 'Hello' }
+
+    assert_equal('Hello', @context['dynamic'])
+  end
+
+  def test_lambda_as_variable
+    @context['dynamic'] = proc { 'Hello' }
+
+    assert_equal('Hello', @context['dynamic'])
+  end
+
+  def test_nested_lambda_as_variable
+    @context['dynamic'] = { "lambda" => proc { 'Hello' } }
+
+    assert_equal('Hello', @context['dynamic.lambda'])
+  end
+
+  def test_array_containing_lambda_as_variable
+    @context['dynamic'] = [1, 2, proc { 'Hello' }, 4, 5]
+
+    assert_equal('Hello', @context['dynamic[2]'])
+  end
+
+  def test_lambda_is_called_once
+    @context['callcount'] = proc {
+      @global ||= 0
+      @global  += 1
+      @global.to_s
+    }
+
+    assert_equal('1', @context['callcount'])
+    assert_equal('1', @context['callcount'])
+    assert_equal('1', @context['callcount'])
+
+    @global = nil
+  end
+
+  def test_nested_lambda_is_called_once
+    @context['callcount'] = { "lambda" => proc {
+                                            @global ||= 0
+                                            @global  += 1
+                                            @global.to_s
+                                          } }
+
+    assert_equal('1', @context['callcount.lambda'])
+    assert_equal('1', @context['callcount.lambda'])
+    assert_equal('1', @context['callcount.lambda'])
+
+    @global = nil
+  end
+
+  def test_lambda_in_array_is_called_once
+    @context['callcount'] = [1, 2, proc {
+                                     @global ||= 0
+                                     @global  += 1
+                                     @global.to_s
+                                   }, 4, 5]
+
+    assert_equal('1', @context['callcount[2]'])
+    assert_equal('1', @context['callcount[2]'])
+    assert_equal('1', @context['callcount[2]'])
+
+    @global = nil
+  end
+
+  def test_access_to_context_from_proc
+    @context.registers[:magic] = 345392
+
+    @context['magic'] = proc { @context.registers[:magic] }
+
+    assert_equal(345392, @context['magic'])
+  end
+
+  def test_to_liquid_and_context_at_first_level
+    @context['category'] = Category.new("foobar")
+    assert_kind_of(CategoryDrop, @context['category'])
+    assert_equal(@context, @context['category'].context)
+  end
+
+  def test_interrupt_avoids_object_allocations
+    assert_no_object_allocations do
+      @context.interrupt?
+    end
+  end
+
+  def test_context_initialization_with_a_proc_in_environment
+    contx = Context.new([test: ->(c) { c['poutine'] }], test: :foo)
+
+    assert(contx)
+    assert_nil(contx['poutine'])
+  end
+
+  def test_apply_global_filter
+    global_filter_proc = ->(output) { "#{output} filtered" }
+
+    context = Context.new
+    context.global_filter = global_filter_proc
+
+    assert_equal('hi filtered', context.apply_global_filter('hi'))
+  end
+
+  def test_static_environments_are_read_with_lower_priority_than_environments
+    context = Context.build(
+      static_environments: { 'shadowed' => 'static', 'unshadowed' => 'static' },
+      environments: { 'shadowed' => 'dynamic' }
+    )
+
+    assert_equal('dynamic', context['shadowed'])
+    assert_equal('static', context['unshadowed'])
+  end
+
+  def test_apply_global_filter_when_no_global_filter_exist
+    context = Context.new
+    assert_equal('hi', context.apply_global_filter('hi'))
+  end
+
+  def test_new_isolated_subcontext_does_not_inherit_variables
+    super_context = Context.new
+    super_context['my_variable'] = 'some value'
+    subcontext = super_context.new_isolated_subcontext
+
+    assert_nil(subcontext['my_variable'])
+  end
+
+  def test_new_isolated_subcontext_inherits_static_environment
+    super_context = Context.build(static_environments: { 'my_environment_value' => 'my value' })
+    subcontext    = super_context.new_isolated_subcontext
+
+    assert_equal('my value', subcontext['my_environment_value'])
+  end
+
+  def test_new_isolated_subcontext_inherits_resource_limits
+    resource_limits = ResourceLimits.new({})
+    super_context   = Context.new({}, {}, {}, false, resource_limits)
+    subcontext      = super_context.new_isolated_subcontext
+    assert_equal(resource_limits, subcontext.resource_limits)
+  end
+
+  def test_new_isolated_subcontext_inherits_exception_renderer
+    super_context = Context.new
+    super_context.exception_renderer = ->(_e) { 'my exception message' }
+    subcontext = super_context.new_isolated_subcontext
+    assert_equal('my exception message', subcontext.handle_error(Liquid::Error.new))
+  end
+
+  def test_new_isolated_subcontext_does_not_inherit_non_static_registers
+    registers = {
+      my_register: :my_value,
+    }
+    super_context = Context.new({}, {}, StaticRegisters.new(registers))
+    super_context.registers[:my_register] = :my_alt_value
+    subcontext                            = super_context.new_isolated_subcontext
+    assert_equal(:my_value, subcontext.registers[:my_register])
+  end
+
+  def test_new_isolated_subcontext_inherits_static_registers
+    super_context = Context.build(registers: { my_register: :my_value })
+    subcontext    = super_context.new_isolated_subcontext
+    assert_equal(:my_value, subcontext.registers[:my_register])
+  end
+
+  def test_new_isolated_subcontext_registers_do_not_pollute_context
+    super_context                      = Context.build(registers: { my_register: :my_value })
+    subcontext                         = super_context.new_isolated_subcontext
+    subcontext.registers[:my_register] = :my_alt_value
+    assert_equal(:my_value, super_context.registers[:my_register])
+  end
+
+  def test_new_isolated_subcontext_inherits_filters
+    my_filter = Module.new do
+      def my_filter(*)
+        'my filter result'
+      end
+    end
+
+    super_context = Context.new
+    super_context.add_filters([my_filter])
+    subcontext    = super_context.new_isolated_subcontext
+    template      = Template.parse('{{ 123 | my_filter }}')
+    assert_equal('my filter result', template.render(subcontext))
+  end
+
+  def test_disables_tag_specified
+    context = Context.new
+    context.with_disabled_tags(%w(foo bar)) do
+      assert_equal true, context.tag_disabled?("foo")
+      assert_equal true, context.tag_disabled?("bar")
+      assert_equal false, context.tag_disabled?("unknown")
+    end
+  end
+
+  def test_disables_nested_tags
+    context = Context.new
+    context.with_disabled_tags(["foo"]) do
+      context.with_disabled_tags(["foo"]) do
+        assert_equal true, context.tag_disabled?("foo")
+        assert_equal false, context.tag_disabled?("bar")
+      end
+      context.with_disabled_tags(["bar"]) do
+        assert_equal true, context.tag_disabled?("foo")
+        assert_equal true, context.tag_disabled?("bar")
+        context.with_disabled_tags(["foo"]) do
+          assert_equal true, context.tag_disabled?("foo")
+          assert_equal true, context.tag_disabled?("bar")
+        end
+      end
+      assert_equal true, context.tag_disabled?("foo")
+      assert_equal false, context.tag_disabled?("bar")
+    end
+  end
+
   def test_override_global_filter
     global = Module.new do
       def notice(output)
@@ -31,4 +618,18 @@ class ContextTest < Minitest::Test
       assert_empty context.errors
     end
   end
-end
+
+  private
+
+  def assert_no_object_allocations
+    unless RUBY_ENGINE == 'ruby'
+      skip("stackprof needed to count object allocations")
+    end
+    require 'stackprof'
+
+    profile = StackProf.run(mode: :object) do
+      yield
+    end
+    assert_equal(0, profile[:samples])
+  end
+end # ContextTest

test/integration/error_handling_test.rb

@@ -40,29 +40,26 @@ class ErrorHandlingTest < Minitest::Test
 
   def test_standard_error
     template = Liquid::Template.parse(' {{ errors.standard_error }} ')
-    context = Liquid::Context.new('errors' => ErrorDrop.new)
-    assert_equal(' Liquid error: standard error ', template.render(context))
+    assert_equal(' Liquid error: standard error ', template.render('errors' => ErrorDrop.new))
 
-    assert_equal(1, context.errors.size)
-    assert_equal(StandardError, context.errors.first.class)
+    assert_equal(1, template.errors.size)
+    assert_equal(StandardError, template.errors.first.class)
   end
 
   def test_syntax
     template = Liquid::Template.parse(' {{ errors.syntax_error }} ')
-    context = Liquid::Context.new('errors' => ErrorDrop.new)
-    assert_equal(' Liquid syntax error: syntax error ', template.render(context))
+    assert_equal(' Liquid syntax error: syntax error ', template.render('errors' => ErrorDrop.new))
 
-    assert_equal(1, context.errors.size)
-    assert_equal(SyntaxError, context.errors.first.class)
+    assert_equal(1, template.errors.size)
+    assert_equal(SyntaxError, template.errors.first.class)
   end
 
   def test_argument
     template = Liquid::Template.parse(' {{ errors.argument_error }} ')
-    context = Liquid::Context.new('errors' => ErrorDrop.new)
-    assert_equal(' Liquid error: argument error ', template.render(context))
+    assert_equal(' Liquid error: argument error ', template.render('errors' => ErrorDrop.new))
 
-    assert_equal(1, context.errors.size)
-    assert_equal(ArgumentError, context.errors.first.class)
+    assert_equal(1, template.errors.size)
+    assert_equal(ArgumentError, template.errors.first.class)
   end
 
   def test_missing_endtag_parse_time_error
@@ -81,10 +78,9 @@ class ErrorHandlingTest < Minitest::Test
 
   def test_lax_unrecognized_operator
     template = Liquid::Template.parse(' {% if 1 =! 2 %}ok{% endif %} ', error_mode: :lax)
-    context = Liquid::Context.new('errors' => ErrorDrop.new)
-    assert_equal(' Liquid error: Unknown operator =! ', template.render(context))
-    assert_equal(1, context.errors.size)
-    assert_equal(Liquid::ArgumentError, context.errors.first.class)
+    assert_equal(' Liquid error: Unknown operator =! ', template.render)
+    assert_equal(1, template.errors.size)
+    assert_equal(Liquid::ArgumentError, template.errors.first.class)
   end
 
   def test_with_line_numbers_adds_numbers_to_parser_errors
@@ -206,11 +202,10 @@ class ErrorHandlingTest < Minitest::Test
   def test_default_exception_renderer_with_internal_error
     template = Liquid::Template.parse('This is a runtime error: {{ errors.runtime_error }}', line_numbers: true)
 
-    context = Liquid::Context.new('errors' => ErrorDrop.new)
-    output = template.render(context)
+    output = template.render('errors' => ErrorDrop.new)
 
     assert_equal('This is a runtime error: Liquid error (line 1): internal', output)
-    assert_equal([Liquid::InternalError], context.errors.map(&:class))
+    assert_equal([Liquid::InternalError], template.errors.map(&:class))
   end
 
   def test_setting_default_exception_renderer
@@ -222,11 +217,10 @@ class ErrorHandlingTest < Minitest::Test
     }
     template = Liquid::Template.parse('This is a runtime error: {{ errors.argument_error }}')
 
-    context = Liquid::Context.new('errors' => ErrorDrop.new)
-    output = template.render(context)
+    output = template.render('errors' => ErrorDrop.new)
 
     assert_equal('This is a runtime error: ', output)
-    assert_equal([Liquid::ArgumentError], context.errors.map(&:class))
+    assert_equal([Liquid::ArgumentError], template.errors.map(&:class))
   ensure
     Liquid::Template.default_exception_renderer = old_exception_renderer if old_exception_renderer
   end
@@ -239,12 +233,11 @@ class ErrorHandlingTest < Minitest::Test
       e.cause
     }
 
-    context = Liquid::Context.new('errors' => ErrorDrop.new)
-    output = template.render(context, exception_renderer: handler)
+    output = template.render({ 'errors' => ErrorDrop.new }, exception_renderer: handler)
 
     assert_equal('This is a runtime error: runtime error', output)
     assert_equal([Liquid::InternalError], exceptions.map(&:class))
-    assert_equal(exceptions, context.errors)
+    assert_equal(exceptions, template.errors)
     assert_equal('#<RuntimeError: runtime error>', exceptions.first.cause.inspect)
   end
 
@@ -257,16 +250,23 @@ class ErrorHandlingTest < Minitest::Test
   def test_included_template_name_with_line_numbers
     old_file_system = Liquid::Template.file_system
 
-    context = Liquid::Context.new('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(context)
+      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", context.errors.first.template_name)
+    assert_equal("product", template.errors.first.template_name)
+  end
+
+  def test_bug_compatible_silencing_of_errors_in_blank_nodes
+    output = Liquid::Template.parse("{% assign x = 0 %}{% if 1 < '2' %}not blank{% assign x = 3 %}{% endif %}{{ x }}").render
+    assert_equal("Liquid error: comparison of Integer with String failed0", output)
+
+    output = Liquid::Template.parse("{% assign x = 0 %}{% if 1 < '2' %}{% assign x = 3 %}{% endif %}{{ x }}").render
+    assert_equal("0", output)
   end
 end

test/integration/registers/disabled_tags_test.rb

@@ -1,27 +0,0 @@
-# frozen_string_literal: true
-
-require 'test_helper'
-
-class DisabledTagsTest < Minitest::Test
-  include Liquid
-
-  class DisableRaw < Block
-    disable_tags "raw"
-  end
-
-  class DisableRawEcho < Block
-    disable_tags "raw", "echo"
-  end
-
-  def test_disables_raw
-    with_custom_tag('disable', DisableRaw) do
-      assert_template_result 'raw usage is not allowed in this contextfoo', '{% disable %}{% raw %}Foobar{% endraw %}{% echo "foo" %}{% enddisable %}'
-    end
-  end
-
-  def test_disables_echo_and_raw
-    with_custom_tag('disable', DisableRawEcho) do
-      assert_template_result 'raw usage is not allowed in this contextecho usage is not allowed in this context', '{% disable %}{% raw %}Foobar{% endraw %}{% echo "foo" %}{% enddisable %}'
-    end
-  end
-end

test/integration/security_test.rb

@@ -43,15 +43,22 @@ class SecurityTest < Minitest::Test
     assert_equal(expected, Template.parse(text).render!(@assigns, filters: SecurityFilter))
   end
 
-  def test_does_not_add_filters_to_symbol_table
+  def test_does_not_permanently_add_filters_to_symbol_table
     current_symbols = Symbol.all_symbols
 
-    test = %( {{ "some_string" | a_bad_filter }} )
+    # MRI imprecisely marks objects found on the C stack, which can result
+    # in uninitialized memory being marked. This can even result in the test failing
+    # deterministically for a given compilation of ruby. Using a separate thread will
+    # keep these writes of the symbol pointer on a separate stack that will be garbage
+    # collected after Thread#join.
+    Thread.new do
+      test = %( {{ "some_string" | a_bad_filter }} )
+      Template.parse(test).render!
+      nil
+    end.join
 
-    template = Template.parse(test)
-    assert_equal([], (Symbol.all_symbols - current_symbols))
+    GC.start
 
-    template.render!
     assert_equal([], (Symbol.all_symbols - current_symbols))
   end
 

test/integration/tag/disableable_test.rb

@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class TagDisableableTest < Minitest::Test
+  include Liquid
+
+  class DisableRaw < Block
+    disable_tags "raw"
+  end
+
+  class DisableRawEcho < Block
+    disable_tags "raw", "echo"
+  end
+
+  class DisableableRaw < Liquid::Raw
+    prepend Liquid::Tag::Disableable
+  end
+
+  class DisableableEcho < Liquid::Echo
+    prepend Liquid::Tag::Disableable
+  end
+
+  def test_disables_raw
+    with_disableable_tags do
+      with_custom_tag('disable', DisableRaw) do
+        output = Template.parse('{% disable %}{% raw %}Foobar{% endraw %}{% echo "foo" %}{% enddisable %}').render
+        assert_equal('Liquid error: raw usage is not allowed in this contextfoo', output)
+      end
+    end
+  end
+
+  def test_disables_echo_and_raw
+    with_disableable_tags do
+      with_custom_tag('disable', DisableRawEcho) do
+        output = Template.parse('{% disable %}{% raw %}Foobar{% endraw %}{% echo "foo" %}{% enddisable %}').render
+        assert_equal('Liquid error: raw usage is not allowed in this contextLiquid error: echo usage is not allowed in this context', output)
+      end
+    end
+  end
+
+  private
+
+  def with_disableable_tags
+    with_custom_tag('raw', DisableableRaw) do
+      with_custom_tag('echo', DisableableEcho) do
+        yield
+      end
+    end
+  end
+end

test/integration/tag_test.rb

@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class TagTest < Minitest::Test
+  include Liquid
+
+  def test_custom_tags_have_a_default_render_to_output_buffer_method_for_backwards_compatibility
+    klass1 = Class.new(Tag) do
+      def render(*)
+        'hello'
+      end
+    end
+
+    with_custom_tag('blabla', klass1) do
+      template = Liquid::Template.parse("{% blabla %}")
+
+      assert_equal 'hello', template.render
+
+      buf    = +''
+      output = template.render({}, output: buf)
+      assert_equal 'hello', output
+      assert_equal 'hello', buf
+      assert_equal buf.object_id, output.object_id
+    end
+
+    klass2 = Class.new(klass1) do
+      def render(*)
+        'foo' + super + 'bar'
+      end
+    end
+
+    with_custom_tag('blabla', klass2) do
+      template = Liquid::Template.parse("{% blabla %}")
+
+      assert_equal 'foohellobar', template.render
+
+      buf    = +''
+      output = template.render({}, output: buf)
+      assert_equal 'foohellobar', output
+      assert_equal 'foohellobar', buf
+      assert_equal buf.object_id, output.object_id
+    end
+  end
+end

test/integration/tags/include_tag_test.rb

@@ -217,9 +217,8 @@ class IncludeTagTest < Minitest::Test
     Liquid::Template.file_system = TestFileSystem.new
 
     a = Liquid::Template.parse(' {% include "nested_template" %}')
-    context = Liquid::Context.new
-    a.render!(context)
-    assert_empty(context.errors)
+    a.render!
+    assert_empty(a.errors)
   end
 
   def test_passing_options_to_included_templates
@@ -258,10 +257,9 @@ class IncludeTagTest < Minitest::Test
 
   def test_including_with_strict_variables
     template = Liquid::Template.parse("{% include 'simple' %}", error_mode: :warn)
-    context = Liquid::Context.new
-    template.render(context, strict_variables: true)
+    template.render(nil, strict_variables: true)
 
-    assert_equal([], context.errors)
+    assert_equal([], template.errors)
   end
 
   def test_break_through_include

test/integration/tags/liquid_tag_test.rb

@@ -82,15 +82,13 @@ class LiquidTagTest < Minitest::Test
   end
 
   def test_nested_liquid_tag
-    assert_usage_increment("liquid_tag_contains_outer_tag", times: 0) do
-      assert_template_result('good', <<~LIQUID)
-        {%- if true %}
-          {%- liquid
-            echo "good"
-          %}
-        {%- endif -%}
-      LIQUID
-    end
+    assert_template_result('good', <<~LIQUID)
+      {%- if true %}
+        {%- liquid
+          echo "good"
+        %}
+      {%- endif -%}
+    LIQUID
   end
 
   def test_cannot_open_blocks_living_past_a_liquid_tag
@@ -102,14 +100,12 @@ class LiquidTagTest < Minitest::Test
     LIQUID
   end
 
-  def test_quirk_can_close_blocks_created_before_a_liquid_tag
-    assert_usage_increment("liquid_tag_contains_outer_tag") do
-      assert_template_result("42", <<~LIQUID)
-        {%- if true -%}
-        42
-        {%- liquid endif -%}
-      LIQUID
-    end
+  def test_cannot_close_blocks_created_before_a_liquid_tag
+    assert_match_syntax_error("syntax error (line 3): 'endif' is not a valid delimiter for liquid tags. use %}", <<~LIQUID)
+      {%- if true -%}
+      42
+      {%- liquid endif -%}
+    LIQUID
   end
 
   def test_liquid_tag_in_raw

test/integration/tags/raw_tag_test.rb

@@ -23,6 +23,7 @@ class RawTagTest < Minitest::Test
     assert_template_result(' Foobar {% {% {% ', '{% raw %} Foobar {% {% {% {% endraw %}')
     assert_template_result(' test {% raw %} {% endraw %}', '{% raw %} test {% raw %} {% {% endraw %}endraw %}')
     assert_template_result(' Foobar {{ invalid 1', '{% raw %} Foobar {{ invalid {% endraw %}{{ 1 }}')
+    assert_template_result(' Foobar {% foo {% bar %}', '{% raw %} Foobar {% foo {% bar %}{% endraw %}')
   end
 
   def test_invalid_raw

test/integration/tags/render_tag_test.rb

@@ -127,7 +127,10 @@ class RenderTagTest < Minitest::Test
       'test_include' => '{% include "foo" %}'
     )
 
-    assert_template_result('include usage is not allowed in this context', '{% render "test_include" %}')
+    exc = assert_raises(Liquid::DisabledError) do
+      Liquid::Template.parse('{% render "test_include" %}').render!
+    end
+    assert_equal('Liquid error: include usage is not allowed in this context', exc.message)
   end
 
   def test_includes_will_not_render_inside_nested_sibling_tags
@@ -137,7 +140,8 @@ class RenderTagTest < Minitest::Test
       'test_include' => '{% include "foo" %}'
     )
 
-    assert_template_result('include usage is not allowed in this contextinclude usage is not allowed in this context', '{% render "nested_render_with_sibling_include" %}')
+    output = Liquid::Template.parse('{% render "nested_render_with_sibling_include" %}').render
+    assert_equal('Liquid error: include usage is not allowed in this contextLiquid error: include usage is not allowed in this context', output)
   end
 
   def test_render_tag_with

test/integration/template_test.rb

@@ -38,6 +38,12 @@ end
 class TemplateTest < Minitest::Test
   include Liquid
 
+  def test_instance_assigns_persist_on_same_template_object_between_parses
+    t = Template.new
+    assert_equal('from instance assigns', t.parse("{% assign foo = 'from instance assigns' %}{{ foo }}").render!)
+    assert_equal('from instance assigns', t.parse("{{ foo }}").render!)
+  end
+
   def test_warnings_is_not_exponential_time
     str = "false"
     100.times do
@@ -48,15 +54,43 @@ class TemplateTest < Minitest::Test
     assert_equal([], Timeout.timeout(1) { t.warnings })
   end
 
+  def test_instance_assigns_persist_on_same_template_parsing_between_renders
+    t = Template.new.parse("{{ foo }}{% assign foo = 'foo' %}{{ foo }}")
+    assert_equal('foo', t.render!)
+    assert_equal('foofoo', t.render!)
+  end
+
   def test_custom_assigns_do_not_persist_on_same_template
     t = Template.new
     assert_equal('from custom assigns', t.parse("{{ foo }}").render!('foo' => 'from custom assigns'))
     assert_equal('', t.parse("{{ foo }}").render!)
+  end
 
+  def test_custom_assigns_squash_instance_assigns
+    t = Template.new
     assert_equal('from instance assigns', t.parse("{% assign foo = 'from instance assigns' %}{{ foo }}").render!)
     assert_equal('from custom assigns', t.parse("{{ foo }}").render!('foo' => 'from custom assigns'))
   end
 
+  def test_persistent_assigns_squash_instance_assigns
+    t = Template.new
+    assert_equal('from instance assigns', t.parse("{% assign foo = 'from instance assigns' %}{{ foo }}").render!)
+    t.assigns['foo'] = 'from persistent assigns'
+    assert_equal('from persistent assigns', t.parse("{{ foo }}").render!)
+  end
+
+  def test_lambda_is_called_once_from_persistent_assigns_over_multiple_parses_and_renders
+    t = Template.new
+    t.assigns['number'] = -> {
+      @global ||= 0
+      @global  += 1
+    }
+    assert_equal('1', t.parse("{{number}}").render!)
+    assert_equal('1', t.parse("{{number}}").render!)
+    assert_equal('1', t.render!)
+    @global = nil
+  end
+
   def test_lambda_is_called_once_from_custom_assigns_over_multiple_parses_and_renders
     t = Template.new
     assigns = { 'number' => -> {
@@ -71,143 +105,125 @@ class TemplateTest < Minitest::Test
 
   def test_resource_limits_works_with_custom_length_method
     t = Template.parse("{% assign foo = bar %}")
-    context = Liquid::Context.new("bar" => SomethingWithLength.new)
-    context.resource_limits.render_length_limit = 42
-    assert_equal("", t.render!(context))
+    t.resource_limits.render_length_limit = 42
+    assert_equal("", t.render!("bar" => SomethingWithLength.new))
   end
 
   def test_resource_limits_render_length
     t = Template.parse("0123456789")
-    context = Liquid::Context.new
-    context.resource_limits.render_length_limit = 5
-    assert_equal("Liquid error: Memory limits exceeded", t.render(context))
-    assert(context.resource_limits.reached?)
+    t.resource_limits.render_length_limit = 9
+    assert_equal("Liquid error: Memory limits exceeded", t.render)
+    assert(t.resource_limits.reached?)
 
-    context.resource_limits.render_length_limit = 10
+    t.resource_limits.render_length_limit = 10
     assert_equal("0123456789", t.render!)
-    refute_nil(context.resource_limits.render_length)
   end
 
   def test_resource_limits_render_score
     t = Template.parse("{% for a in (1..10) %} {% for a in (1..10) %} foo {% endfor %} {% endfor %}")
-    context = Liquid::Context.new
-    context.resource_limits.render_score_limit = 50
-    assert_equal("Liquid error: Memory limits exceeded", t.render(context))
-    assert(context.resource_limits.reached?)
+    t.resource_limits.render_score_limit = 50
+    assert_equal("Liquid error: Memory limits exceeded", t.render)
+    assert(t.resource_limits.reached?)
 
     t = Template.parse("{% for a in (1..100) %} foo {% endfor %}")
-    context.resource_limits.render_score_limit = 50
-    assert_equal("Liquid error: Memory limits exceeded", t.render(context))
-    assert(context.resource_limits.reached?)
+    t.resource_limits.render_score_limit = 50
+    assert_equal("Liquid error: Memory limits exceeded", t.render)
+    assert(t.resource_limits.reached?)
 
-    context.resource_limits.render_score_limit = 200
-    assert_equal((" foo " * 100), t.render!(context))
-    refute_nil(context.resource_limits.render_score)
+    t.resource_limits.render_score_limit = 200
+    assert_equal((" foo " * 100), t.render!)
+    refute_nil(t.resource_limits.render_score)
   end
 
   def test_resource_limits_assign_score
     t = Template.parse("{% assign foo = 42 %}{% assign bar = 23 %}")
-    context = Liquid::Context.new
-    context.resource_limits.assign_score_limit = 1
-    assert_equal("Liquid error: Memory limits exceeded", t.render(context))
-    assert(context.resource_limits.reached?)
+    t.resource_limits.assign_score_limit = 1
+    assert_equal("Liquid error: Memory limits exceeded", t.render)
+    assert(t.resource_limits.reached?)
 
-    context.resource_limits.assign_score_limit = 2
-    assert_equal("", t.render!(context))
-    refute_nil(context.resource_limits.assign_score)
+    t.resource_limits.assign_score_limit = 2
+    assert_equal("", t.render!)
+    refute_nil(t.resource_limits.assign_score)
   end
 
   def test_resource_limits_assign_score_counts_bytes_not_characters
     t = Template.parse("{% assign foo = 'すごい' %}")
-    context = Liquid::Context.new
-    t.render(context)
-    assert_equal(9, context.resource_limits.assign_score)
+    t.render
+    assert_equal(9, t.resource_limits.assign_score)
 
     t = Template.parse("{% capture foo %}すごい{% endcapture %}")
-    t.render(context)
-    assert_equal(9, context.resource_limits.assign_score)
+    t.render
+    assert_equal(9, t.resource_limits.assign_score)
   end
 
   def test_resource_limits_assign_score_nested
     t = Template.parse("{% assign foo = 'aaaa' | reverse %}")
 
-    context = Liquid::Context.new
-    context.resource_limits.assign_score_limit = 3
-    assert_equal("Liquid error: Memory limits exceeded", t.render(context))
-    assert(context.resource_limits.reached?)
+    t.resource_limits.assign_score_limit = 3
+    assert_equal("Liquid error: Memory limits exceeded", t.render)
+    assert(t.resource_limits.reached?)
 
-    context.resource_limits.assign_score_limit = 5
-    assert_equal("", t.render!(context))
+    t.resource_limits.assign_score_limit = 5
+    assert_equal("", t.render!)
   end
 
   def test_resource_limits_aborts_rendering_after_first_error
     t = Template.parse("{% for a in (1..100) %} foo1 {% endfor %} bar {% for a in (1..100) %} foo2 {% endfor %}")
-    context = Liquid::Context.new
-    context.resource_limits.render_score_limit = 50
-    assert_equal("Liquid error: Memory limits exceeded", t.render(context))
-    assert(context.resource_limits.reached?)
+    t.resource_limits.render_score_limit = 50
+    assert_equal("Liquid error: Memory limits exceeded", t.render)
+    assert(t.resource_limits.reached?)
   end
 
   def test_resource_limits_hash_in_template_gets_updated_even_if_no_limits_are_set
-    t = Template.parse("{% for a in (1..100) %} {% assign foo = 1 %} {% endfor %}")
-    context = Liquid::Context.new
-    t.render!(context)
-    assert(context.resource_limits.assign_score > 0)
-    assert(context.resource_limits.render_score > 0)
-    assert(context.resource_limits.render_length > 0)
+    t = Template.parse("{% for a in (1..100) %}x{% assign foo = 1 %} {% endfor %}")
+    t.render!
+    assert(t.resource_limits.assign_score > 0)
+    assert(t.resource_limits.render_score > 0)
   end
 
   def test_render_length_persists_between_blocks
     t = Template.parse("{% if true %}aaaa{% endif %}")
-    context = Liquid::Context.new
-    context.resource_limits.render_length_limit = 7
-    assert_equal("Liquid error: Memory limits exceeded", t.render(context))
-    context.resource_limits.render_length_limit = 8
-    assert_equal("aaaa", t.render(context))
+    t.resource_limits.render_length_limit = 3
+    assert_equal("Liquid error: Memory limits exceeded", t.render)
+    t.resource_limits.render_length_limit = 4
+    assert_equal("aaaa", t.render)
 
     t = Template.parse("{% if true %}aaaa{% endif %}{% if true %}bbb{% endif %}")
-    context = Liquid::Context.new
-    context.resource_limits.render_length_limit = 13
-    assert_equal("Liquid error: Memory limits exceeded", t.render(context))
-    context.resource_limits.render_length_limit = 14
-    assert_equal("aaaabbb", t.render(context))
+    t.resource_limits.render_length_limit = 6
+    assert_equal("Liquid error: Memory limits exceeded", t.render)
+    t.resource_limits.render_length_limit = 7
+    assert_equal("aaaabbb", t.render)
 
     t = Template.parse("{% if true %}a{% endif %}{% if true %}b{% endif %}{% if true %}a{% endif %}{% if true %}b{% endif %}{% if true %}a{% endif %}{% if true %}b{% endif %}")
-    context = Liquid::Context.new
-    context.resource_limits.render_length_limit = 5
-    assert_equal("Liquid error: Memory limits exceeded", t.render(context))
-    context.resource_limits.render_length_limit = 11
-    assert_equal("Liquid error: Memory limits exceeded", t.render(context))
-    context.resource_limits.render_length_limit = 12
-    assert_equal("ababab", t.render(context))
+    t.resource_limits.render_length_limit = 5
+    assert_equal("Liquid error: Memory limits exceeded", t.render)
+    t.resource_limits.render_length_limit = 6
+    assert_equal("ababab", t.render)
   end
 
   def test_render_length_uses_number_of_bytes_not_characters
     t = Template.parse("{% if true %}すごい{% endif %}")
-    context = Liquid::Context.new
-    context.resource_limits.render_length_limit = 10
-    assert_equal("Liquid error: Memory limits exceeded", t.render(context))
-    context.resource_limits.render_length_limit = 18
-    assert_equal("すごい", t.render(context))
+    t.resource_limits.render_length_limit = 8
+    assert_equal("Liquid error: Memory limits exceeded", t.render)
+    t.resource_limits.render_length_limit = 9
+    assert_equal("すごい", t.render)
   end
 
   def test_default_resource_limits_unaffected_by_render_with_context
     context = Context.new
-    t = Template.parse("{% for a in (1..100) %} {% assign foo = 1 %} {% endfor %}")
+    t = Template.parse("{% for a in (1..100) %}x{% assign foo = 1 %} {% endfor %}")
     t.render!(context)
     assert(context.resource_limits.assign_score > 0)
     assert(context.resource_limits.render_score > 0)
-    assert(context.resource_limits.render_length > 0)
   end
 
   def test_can_use_drop_as_context
     t = Template.new
+    t.registers['lulz'] = 'haha'
     drop = TemplateContextDrop.new
-    context = Liquid::Context.build(environments: drop, registers: { 'lulz' => 'haha' })
-    drop.context = context
-    assert_equal('fizzbuzz', t.parse('{{foo}}').render!(context))
-    assert_equal('bar', t.parse('{{bar}}').render!(context))
-    assert_equal('haha', t.parse("{{baz}}").render!(context))
+    assert_equal('fizzbuzz', t.parse('{{foo}}').render!(drop))
+    assert_equal('bar', t.parse('{{bar}}').render!(drop))
+    assert_equal('haha', t.parse("{{baz}}").render!(drop))
   end
 
   def test_render_bang_force_rethrow_errors_on_passed_context
@@ -259,27 +275,25 @@ class TemplateTest < Minitest::Test
   end
 
   def test_undefined_variables
-    t = Template.parse("{{x}} {{y}} {{z.a}} {{z.b}} {{z.c.d}}")
-    context = Liquid::Context.new('x' => 33, 'z' => { 'a' => 32, 'c' => { 'e' => 31 } })
-    result = t.render(context, strict_variables: true)
+    t      = Template.parse("{{x}} {{y}} {{z.a}} {{z.b}} {{z.c.d}}")
+    result = t.render({ 'x' => 33, 'z' => { 'a' => 32, 'c' => { 'e' => 31 } } }, strict_variables: true)
 
     assert_equal('33  32  ', result)
-    assert_equal(3, context.errors.count)
-    assert_instance_of(Liquid::UndefinedVariable, context.errors[0])
-    assert_equal('Liquid error: undefined variable y', context.errors[0].message)
-    assert_instance_of(Liquid::UndefinedVariable, context.errors[1])
-    assert_equal('Liquid error: undefined variable b', context.errors[1].message)
-    assert_instance_of(Liquid::UndefinedVariable, context.errors[2])
-    assert_equal('Liquid error: undefined variable d', context.errors[2].message)
+    assert_equal(3, t.errors.count)
+    assert_instance_of(Liquid::UndefinedVariable, t.errors[0])
+    assert_equal('Liquid error: undefined variable y', t.errors[0].message)
+    assert_instance_of(Liquid::UndefinedVariable, t.errors[1])
+    assert_equal('Liquid error: undefined variable b', t.errors[1].message)
+    assert_instance_of(Liquid::UndefinedVariable, t.errors[2])
+    assert_equal('Liquid error: undefined variable d', t.errors[2].message)
   end
 
   def test_nil_value_does_not_raise
     Liquid::Template.error_mode = :strict
-    t = Template.parse("some{{x}}thing")
-    context = Liquid::Context.new('x' => nil)
-    result = t.render!(context, strict_variables: true)
+    t                           = Template.parse("some{{x}}thing")
+    result                      = t.render!({ 'x' => nil }, strict_variables: true)
 
-    assert_equal(0, context.errors.count)
+    assert_equal(0, t.errors.count)
     assert_equal('something', result)
   end
 
@@ -294,13 +308,11 @@ class TemplateTest < Minitest::Test
   def test_undefined_drop_methods
     d = DropWithUndefinedMethod.new
     t = Template.new.parse('{{ foo }} {{ woot }}')
-    context = Liquid::Context.new(d)
-    d.context = context
-    result = t.render(context, strict_variables: true)
+    result = t.render(d, strict_variables: true)
 
     assert_equal('foo ', result)
-    assert_equal(1, context.errors.count)
-    assert_instance_of(Liquid::UndefinedDropMethod, context.errors[0])
+    assert_equal(1, t.errors.count)
+    assert_instance_of(Liquid::UndefinedDropMethod, t.errors[0])
   end
 
   def test_undefined_drop_methods_raise
@@ -319,13 +331,12 @@ class TemplateTest < Minitest::Test
         "-#{v}-"
       end
     end
-    context = Liquid::Context.new('a' => 123, 'x' => 'foo')
-    result = t.render(context, filters: [filters], strict_filters: true)
+    result = t.render({ 'a' => 123, 'x' => 'foo' }, filters: [filters], strict_filters: true)
 
     assert_equal('123 ', result)
-    assert_equal(1, context.errors.count)
-    assert_instance_of(Liquid::UndefinedFilter, context.errors[0])
-    assert_equal('Liquid error: undefined filter somefilter1', context.errors[0].message)
+    assert_equal(1, t.errors.count)
+    assert_instance_of(Liquid::UndefinedFilter, t.errors[0])
+    assert_equal('Liquid error: undefined filter somefilter1', t.errors[0].message)
   end
 
   def test_undefined_filters_raise
@@ -345,48 +356,4 @@ class TemplateTest < Minitest::Test
     result = t.render('x' => 1, 'y' => 5)
     assert_equal('12345', result)
   end
-
-  def test_render_uses_correct_disabled_tags_instance
-    Liquid::Template.file_system = StubFileSystem.new(
-      'foo' => 'bar',
-      'test_include' => '{% include "foo" %}'
-    )
-
-    disabled_tags = DisabledTags.new
-    context = Context.build(registers: { disabled_tags: disabled_tags })
-
-    source = "{% render 'test_include' %}"
-    parse_context = Liquid::ParseContext.new(line_numbers: true, error_mode: :strict)
-    document = Document.parse(Liquid::Tokenizer.new(source, true), parse_context)
-
-    assert_equal("include usage is not allowed in this context", document.render(context))
-  end
-
-  def test_render_sets_context_static_register_when_register_key_does_exist
-    disabled_tags_for_test = DisabledTags.new
-    Template.add_register(:disabled_tags, disabled_tags_for_test)
-
-    t = Template.parse("{% if true %} Test Template {% endif %}")
-
-    context = Context.new
-    refute(context.registers.key?(:disabled_tags))
-
-    t.render(context)
-
-    assert(context.registers.key?(:disabled_tags))
-    assert_equal(disabled_tags_for_test, context.registers[:disabled_tags])
-  end
-
-  def test_render_does_not_override_context_static_register_when_register_key_exists
-    context = Context.new
-    context.registers[:random_register] = nil
-    Template.add_register(:random_register, {})
-
-    t = Template.parse("{% if true %} Test Template {% endif %}")
-
-    t.render(context)
-
-    assert_nil(context.registers[:random_register])
-    assert(context.registers.key?(:random_register))
-  end
 end

test/integration/trim_mode_test.rb

@@ -528,4 +528,32 @@ class TrimModeTest < Minitest::Test
     END_EXPECTED
     assert_template_result(expected, text)
   end
+
+  def test_pre_trim_blank_preceding_text
+    template = Liquid::Template.parse("\n{%- raw %}{% endraw %}")
+    assert_equal("", template.render)
+
+    template = Liquid::Template.parse("\n{%- if true %}{% endif %}")
+    assert_equal("", template.render)
+
+    template = Liquid::Template.parse("{{ 'B' }} \n{%- if true %}C{% endif %}")
+    assert_equal("BC", template.render)
+  end
+
+  def test_bug_compatible_pre_trim
+    template = Liquid::Template.parse("\n {%- raw %}{% endraw %}", bug_compatible_whitespace_trimming: true)
+    assert_equal("\n", template.render)
+
+    template = Liquid::Template.parse("\n {%- if true %}{% endif %}", bug_compatible_whitespace_trimming: true)
+    assert_equal("\n", template.render)
+
+    template = Liquid::Template.parse("{{ 'B' }} \n{%- if true %}C{% endif %}", bug_compatible_whitespace_trimming: true)
+    assert_equal("B C", template.render)
+
+    template = Liquid::Template.parse("B\n {%- raw %}{% endraw %}", bug_compatible_whitespace_trimming: true)
+    assert_equal("B", template.render)
+
+    template = Liquid::Template.parse("B\n {%- if true %}{% endif %}", bug_compatible_whitespace_trimming: true)
+    assert_equal("B", template.render)
+  end
 end # TrimModeTest

test/integration/variable_test.rb

@@ -51,10 +51,29 @@ class VariableTest < Minitest::Test
     assert_equal('cat', Template.parse("{{ nil | append: 'cat' }}").render!)
   end
 
+  def test_preset_assigns
+    template                 = Template.parse(%({{ test }}))
+    template.assigns['test'] = 'worked'
+    assert_equal('worked', template.render!)
+  end
+
   def test_reuse_parsed_template
-    template = Template.parse(%({{ greeting }} {{ name }}))
+    template                     = Template.parse(%({{ greeting }} {{ name }}))
+    template.assigns['greeting'] = 'Goodbye'
     assert_equal('Hello Tobi', template.render!('greeting' => 'Hello', 'name' => 'Tobi'))
-    assert_equal('Goodbye Brian', template.render!('greeting' => 'Goodbye', 'name' => 'Brian'))
+    assert_equal('Hello ', template.render!('greeting' => 'Hello', 'unknown' => 'Tobi'))
+    assert_equal('Hello Brian', template.render!('greeting' => 'Hello', 'name' => 'Brian'))
+    assert_equal('Goodbye Brian', template.render!('name' => 'Brian'))
+    assert_equal({ 'greeting' => 'Goodbye' }, template.assigns)
+  end
+
+  def test_assigns_not_polluted_from_template
+    template                 = Template.parse(%({{ test }}{% assign test = 'bar' %}{{ test }}))
+    template.assigns['test'] = 'baz'
+    assert_equal('bazbar', template.render!)
+    assert_equal('bazbar', template.render!)
+    assert_equal('foobar', template.render!('test' => 'foo'))
+    assert_equal('bazbar', template.render!)
   end
 
   def test_hash_with_default_proc

test/test_helper.rb

@@ -98,10 +98,17 @@ module Minitest
     end
 
     def with_custom_tag(tag_name, tag_class)
-      Liquid::Template.register_tag(tag_name, tag_class)
-      yield
-    ensure
-      Liquid::Template.tags.delete(tag_name)
+      old_tag = Liquid::Template.tags[tag_name]
+      begin
+        Liquid::Template.register_tag(tag_name, tag_class)
+        yield
+      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

@@ -45,53 +45,9 @@ class BlockUnitTest < Minitest::Test
     assert_equal(3, template.root.nodelist.size)
   end
 
-  def test_with_custom_tag
-    with_custom_tag('testtag', Block) do
-      assert Liquid::Template.parse("{% testtag %} {% endtesttag %}")
-    end
-  end
-
-  def test_custom_block_tags_have_a_default_render_to_output_buffer_method_for_backwards_compatibility
-    klass1 = Class.new(Block) do
-      def render(*)
-        'hello'
-      end
-    end
-
-    with_custom_tag('blabla', klass1) do
-      template = Liquid::Template.parse("{% blabla %} bla {% endblabla %}")
-
-      assert_equal 'hello', template.render
-
-      buf    = +''
-      output = template.render({}, output: buf)
-      assert_equal 'hello', output
-      assert_equal 'hello', buf
-      assert_equal buf.object_id, output.object_id
-    end
-
-    klass2 = Class.new(klass1) do
-      def render(*)
-        'foo' + super + 'bar'
-      end
-    end
-
-    with_custom_tag('blabla', klass2) do
-      template = Liquid::Template.parse("{% blabla %} foo {% endblabla %}")
-
-      assert_equal 'foohellobar', template.render
-
-      buf    = +''
-      output = template.render({}, output: buf)
-      assert_equal 'foohellobar', output
-      assert_equal 'foohellobar', buf
-      assert_equal buf.object_id, output.object_id
-    end
-  end
-
   private
 
   def block_types(nodelist)
     nodelist.collect(&:class)
   end
-end # VariableTest
+end

test/unit/optimizer_test.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class OptimizerUnitTest < Minitest::Test
+  include Liquid
+
+  def test_combines_append_filters
+    optimizer = Optimizer.new
+    var = Variable.new('hello | append: "a" | append: b', ParseContext.new)
+    var = optimizer.optimize(var)
+    assert_equal([
+      ['append_all', ["a", VariableLookup.new("b")]]
+    ], var.filters)
+  end
+end

test/unit/registers/disabled_tags_unit_test.rb

@@ -1,36 +0,0 @@
-# frozen_string_literal: true
-
-require 'test_helper'
-
-class DisabledTagsUnitTest < Minitest::Test
-  include Liquid
-
-  def test_disables_tag_specified
-    register = DisabledTags.new
-    register.disable(%w(foo bar)) do
-      assert_equal true, register.disabled?("foo")
-      assert_equal true, register.disabled?("bar")
-      assert_equal false, register.disabled?("unknown")
-    end
-  end
-
-  def test_disables_nested_tags
-    register = DisabledTags.new
-    register.disable(["foo"]) do
-      register.disable(["foo"]) do
-        assert_equal true, register.disabled?("foo")
-        assert_equal false, register.disabled?("bar")
-      end
-      register.disable(["bar"]) do
-        assert_equal true, register.disabled?("foo")
-        assert_equal true, register.disabled?("bar")
-        register.disable(["foo"]) do
-          assert_equal true, register.disabled?("foo")
-          assert_equal true, register.disabled?("bar")
-        end
-      end
-      assert_equal true, register.disabled?("foo")
-      assert_equal false, register.disabled?("bar")
-    end
-  end
-end

test/unit/tag_unit_test.rb

@@ -20,42 +20,4 @@ class TagUnitTest < Minitest::Test
     tag = Tag.parse("some_tag", "", Tokenizer.new(""), ParseContext.new)
     assert_equal('some_tag', tag.tag_name)
   end
-
-  def test_custom_tags_have_a_default_render_to_output_buffer_method_for_backwards_compatibility
-    klass1 = Class.new(Tag) do
-      def render(*)
-        'hello'
-      end
-    end
-
-    with_custom_tag('blabla', klass1) do
-      template = Liquid::Template.parse("{% blabla %}")
-
-      assert_equal 'hello', template.render
-
-      buf    = +''
-      output = template.render({}, output: buf)
-      assert_equal 'hello', output
-      assert_equal 'hello', buf
-      assert_equal buf.object_id, output.object_id
-    end
-
-    klass2 = Class.new(klass1) do
-      def render(*)
-        'foo' + super + 'bar'
-      end
-    end
-
-    with_custom_tag('blabla', klass2) do
-      template = Liquid::Template.parse("{% blabla %}")
-
-      assert_equal 'foohellobar', template.render
-
-      buf    = +''
-      output = template.render({}, output: buf)
-      assert_equal 'foohellobar', output
-      assert_equal 'foohellobar', buf
-      assert_equal buf.object_id, output.object_id
-    end
-  end
 end