Extract rescue code from BlockBody#render_node for re-use in liquid-c

since I would like to continue supporting these tests in liquid-c
in the foreseeable future.

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'
@@ -86,4 +88,3 @@ require 'liquid/template_factory'
 # 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)
@@ -50,8 +55,14 @@ 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"

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)
+    def self.unknown_tag_in_liquid_tag(tag, parse_context)
-      yield end_tag_name, end_tag_markup
+      Block.raise_unknown_tag(tag, 'liquid', '%}', parse_context)
-    ensure
-      Usage.increment("liquid_tag_contains_outer_tag") unless $ERROR_INFO.is_a?(SyntaxError)
     end
 
-    private def parse_liquid_tag(markup, parse_context, &block)
+    # @api private
-      liquid_tag_tokenizer = Tokenizer.new(markup, line_number: parse_context.line_number, for_liquid_tag: true)
+    def self.raise_missing_tag_terminator(token, parse_context)
-      parse_for_liquid_tag(liquid_tag_tokenizer, parse_context) do |end_tag_name, end_tag_markup|
+      raise SyntaxError, parse_context.locale.t("errors.syntax.tag_termination", token: token, tag_end: TagEnd.inspect)
-        next unless end_tag_name
+    end
-        self.class.unknown_tag_in_liquid_tag(end_tag_name, end_tag_markup, &block)
+
+    # @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
+        if node.instance_of?(String)
-
-        case node
-        when 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 %}
+          # or {% continue %}. These tags may also occur through Block or Include tags.
-          context.push_interrupt(node.interrupt)
+          break if context.interrupt? # might have happened in a for-block
-          break
-        else # Other non-Block tags
-          render_node(context, output, node)
-          break if context.interrupt? # might have happened through an include
         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)
+      BlockBody.render_node(context, output, node)
-        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"
     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

@@ -44,6 +44,7 @@ module Liquid
       @interrupts    = []
       @filters       = []
       @global_filter = nil
+      @disabled_tags = {}
     end
     # rubocop:enable Metrics/ParameterLists
 
@@ -144,6 +145,7 @@ module Liquid
         subcontext.strainer = nil
         subcontext.errors   = errors
         subcontext.warnings = warnings
+        subcontext.disabled_tags = @disabled_tags
       end
     end
 
@@ -208,9 +210,24 @@ 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
 

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)
+    attr_reader :parse_context, :body
-      super do |end_tag_name, _end_tag_params|
+
-        unknown_tag(end_tag_name, parse_context) if end_tag_name
+    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,
+      'blank' => '',
-      'empty' => MethodLiteral.new(:empty?, '').freeze
+      'empty' => ''
     }.freeze
 
     SINGLE_QUOTED_STRING = /\A'(.*)'\z/m

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
+  module BlockBodyProfilingHook
-    def render_node_with_profiling(context, output, node)
+    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
+  module IncludeProfilingHook
-    def render_to_output_buffer_with_profiling(context, output)
+    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,
+    attr_accessor :render_length_limit, :render_score_limit, :assign_score_limit
-      :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) ||
+      @reached_limit
-        (@render_score_limit && @render_score > @render_score_limit) ||
-        (@assign_score_limit && @assign_score > @assign_score_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/tag.rb

@@ -13,15 +13,13 @@ module Liquid
         tag
       end
 
-      def disable_tags(*tags)
+      def disable_tags(*tag_names)
-        disabled_tags.push(*tags)
+        @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
+    INTERRUPT = BreakInterrupt.new.freeze
-      BreakInterrupt.new
+
+    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
+      context.resource_limits.with_capture do
-      super
+        capture_output = render(context)
-      context.scopes.last[@to] = output
+        context.scopes.last[@to] = capture_output
-      context.resource_limits.assign_score += (output.bytesize - previous_output_size)
+      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
+    INTERRUPT = ContinueInterrupt.new.freeze
-      ContinueInterrupt.new
+
+    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)
+      if parse_body(@for_block, tokens)
-      parse_body(@else_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/template.rb

@@ -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)
@@ -194,10 +186,6 @@ module Liquid
         context.add_filters(args.pop)
       end
 
-      Template.registers.each do |key, register|
-        context_register[key] = register unless context_register.key?(key)
-      end
-
       # Retrying a render resets resource usage
       context.resource_limits.reset
 

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/error_handling_test.rb

@@ -261,4 +261,12 @@ class ErrorHandlingTest < Minitest::Test
     assert_equal("Argument error:\nLiquid error (product line 1): argument error", page)
     assert_equal("product", template.errors.first.template_name)
   end
+
+  def test_bug_compatible_silencing_of_errors_in_blank_nodes
+    output = Liquid::Template.parse("{% assign x = 0 %}{% if 1 < '2' %}not blank{% assign x = 3 %}{% endif %}{{ x }}").render
+    assert_equal("Liquid error: comparison of Integer with String failed0", output)
+
+    output = Liquid::Template.parse("{% assign x = 0 %}{% if 1 < '2' %}{% assign x = 3 %}{% endif %}{{ x }}").render
+    assert_equal("0", output)
+  end
 end

test/integration/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)
+    GC.start
-    assert_equal([], (Symbol.all_symbols - current_symbols))
 
-    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/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)
-      assert_template_result('good', <<~LIQUID)
+      {%- if true %}
-        {%- if true %}
+        {%- liquid
-          {%- liquid
+          echo "good"
-            echo "good"
+        %}
-          %}
+      {%- endif -%}
-        {%- endif -%}
+    LIQUID
-      LIQUID
-    end
   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
+  def test_cannot_close_blocks_created_before_a_liquid_tag
-    assert_usage_increment("liquid_tag_contains_outer_tag") do
+    assert_match_syntax_error("syntax error (line 3): 'endif' is not a valid delimiter for liquid tags. use %}", <<~LIQUID)
-      assert_template_result("42", <<~LIQUID)
+      {%- if true -%}
-        {%- if true -%}
+      42
-        42
+      {%- liquid endif -%}
-        {%- liquid endif -%}
+    LIQUID
-      LIQUID
-    end
   end
 
   def test_liquid_tag_in_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

@@ -111,13 +111,12 @@ class TemplateTest < Minitest::Test
 
   def test_resource_limits_render_length
     t = Template.parse("0123456789")
-    t.resource_limits.render_length_limit = 5
+    t.resource_limits.render_length_limit = 9
     assert_equal("Liquid error: Memory limits exceeded", t.render)
     assert(t.resource_limits.reached?)
 
     t.resource_limits.render_length_limit = 10
     assert_equal("0123456789", t.render!)
-    refute_nil(t.resource_limits.render_length)
   end
 
   def test_resource_limits_render_score
@@ -176,50 +175,46 @@ class TemplateTest < Minitest::Test
   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 %}")
+    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)
-    assert(t.resource_limits.render_length > 0)
   end
 
   def test_render_length_persists_between_blocks
     t = Template.parse("{% if true %}aaaa{% endif %}")
-    t.resource_limits.render_length_limit = 7
+    t.resource_limits.render_length_limit = 3
     assert_equal("Liquid error: Memory limits exceeded", t.render)
-    t.resource_limits.render_length_limit = 8
+    t.resource_limits.render_length_limit = 4
     assert_equal("aaaa", t.render)
 
     t = Template.parse("{% if true %}aaaa{% endif %}{% if true %}bbb{% endif %}")
-    t.resource_limits.render_length_limit = 13
+    t.resource_limits.render_length_limit = 6
     assert_equal("Liquid error: Memory limits exceeded", t.render)
-    t.resource_limits.render_length_limit = 14
+    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 %}")
     t.resource_limits.render_length_limit = 5
     assert_equal("Liquid error: Memory limits exceeded", t.render)
-    t.resource_limits.render_length_limit = 11
+    t.resource_limits.render_length_limit = 6
-    assert_equal("Liquid error: Memory limits exceeded", t.render)
-    t.resource_limits.render_length_limit = 12
     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 %}")
-    t.resource_limits.render_length_limit = 10
+    t.resource_limits.render_length_limit = 8
     assert_equal("Liquid error: Memory limits exceeded", t.render)
-    t.resource_limits.render_length_limit = 18
+    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
@@ -361,48 +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/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)
+      old_tag = Liquid::Template.tags[tag_name]
-      yield
+      begin
-    ensure
+        Liquid::Template.register_tag(tag_name, tag_class)
-      Liquid::Template.tags.delete(tag_name)
+        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/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