Default Block#blank? to false regardless of whether the body is blank

[StaticRegisters] Add test coverage

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

@@ -4,11 +4,6 @@ module Liquid
   class Block < Tag
     MAX_DEPTH = 100
 
-    def initialize(tag_name, markup, options)
-      super
-      @blank = true
-    end
-
     def parse(tokens)
       @body = BlockBody.new
       while parse_body(@body, tokens)
@@ -20,15 +15,16 @@ module Liquid
       @body.render(context)
     end
 
-    def blank?
-      @blank
-    end
-
     def nodelist
       @body.nodelist
     end
 
     def unknown_tag(tag, _params, _tokens)
+      Block.raise_unknown_tag(tag, 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)
@@ -59,8 +55,6 @@ module Liquid
       parse_context.depth += 1
       begin
         body.parse(tokens, parse_context) do |end_tag_name, end_tag_params|
-          @blank &&= body.blank?
-
           return false if end_tag_name == block_delimiter
           unless end_tag_name
             raise SyntaxError, parse_context.locale.t("errors.syntax.tag_never_closed", block_name: block_name)

lib/liquid/block_body.rb

@@ -54,21 +54,20 @@ 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)
+    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|
-        next unless end_tag_name
-        self.class.unknown_tag_in_liquid_tag(end_tag_name, end_tag_markup, &block)
+      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, &block)
+    private def parse_for_document(tokenizer, parse_context)
       while (token = tokenizer.shift)
         next if token.empty?
         case
@@ -87,7 +86,7 @@ module Liquid
           end
 
           if tag_name == 'liquid'
-            parse_liquid_tag(markup, parse_context, &block)
+            parse_liquid_tag(markup, parse_context)
             next
           end
 
@@ -131,6 +130,26 @@ 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
@@ -142,23 +161,14 @@ module Liquid
       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
 
@@ -171,13 +181,7 @@ 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
+      node.render_to_output_buffer(context, output)
     rescue UndefinedVariable, UndefinedDropMethod, UndefinedFilter => e
       context.handle_error(e, node.line_number)
     rescue ::StandardError => e
@@ -185,11 +189,6 @@ module Liquid
       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?

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/errors.rb

@@ -46,7 +46,6 @@ module Liquid
   StandardError       = Class.new(Error)
   SyntaxError         = Class.new(Error)
   StackLevelError     = Class.new(Error)
-  TaintedError        = Class.new(Error)
   MemoryError         = Class.new(Error)
   ZeroDivisionError   = Class.new(Error)
   FloatDomainError    = Class.new(Error)
@@ -54,5 +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/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/standardfilters.rb

@@ -41,7 +41,7 @@ module Liquid
     end
 
     def escape(input)
-      CGI.escapeHTML(input.to_s).untaint unless input.nil?
+      CGI.escapeHTML(input.to_s) unless input.nil?
     end
     alias_method :h, :escape
 

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/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 +25,9 @@ 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)
+      capture_output = render(context)
+      context.scopes.last[@to] = capture_output
+      context.resource_limits.assign_score += capture_output.bytesize
       output
     end
 

lib/liquid/tags/case.rb

@@ -21,6 +21,14 @@ module Liquid
     def parse(tokens)
       body = BlockBody.new
       body = @blocks.last.attachment while parse_body(body, tokens)
+      @blank = @blocks.all? { |condition| condition.attachment.blank? }
+      if @blank
+        @blocks.each { |condition| condition.attachment.remove_blank_strings }
+      end
+    end
+
+    def blank?
+      @blank
     end
 
     def nodelist

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

@@ -59,8 +59,18 @@ module Liquid
     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
+      @blank = @for_block.blank? && (@else_block.nil? || @else_block.blank?)
+      if @blank
+        @for_block.remove_blank_strings
+        @else_block&.remove_blank_strings
+      end
+    end
+
+    def blank?
+      @blank
     end
 
     def nodelist

lib/liquid/tags/if.rb

@@ -31,6 +31,14 @@ module Liquid
     def parse(tokens)
       while parse_body(@blocks.last.attachment, tokens)
       end
+      @blank = @blocks.all? { |condition| condition.attachment.blank? }
+      if @blank
+        @blocks.each { |condition| condition.attachment.remove_blank_strings }
+      end
+    end
+
+    def blank?
+      @blank
     end
 
     def unknown_tag(tag, markup, tokens)

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

@@ -64,23 +64,6 @@ module Liquid
       attr_accessor :error_mode
       Template.error_mode = :lax
 
-      attr_reader :taint_mode
-
-      # Sets how strict the taint checker should be.
-      # :lax is the default, and ignores the taint flag completely
-      # :warn adds a warning, but does not interrupt the rendering
-      # :error raises an error when tainted output is used
-      # @deprecated Since it is being deprecated in ruby itself.
-      def taint_mode=(mode)
-        taint_supported = Object.new.taint.tainted?
-        if mode != :lax && !taint_supported
-          raise NotImplementedError, "#{RUBY_ENGINE} #{RUBY_VERSION} doesn't support taint checking"
-        end
-        @taint_mode = mode
-      end
-
-      Template.taint_mode = :lax
-
       attr_accessor :default_exception_renderer
       Template.default_exception_renderer = lambda do |exception|
         exception
@@ -97,14 +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)
@@ -211,10 +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
 

lib/liquid/variable.rb

@@ -86,9 +86,7 @@ module Liquid
         context.invoke(filter_name, output, *filter_args)
       end
 
-      obj = context.apply_global_filter(obj)
-      taint_check(context, obj)
-      obj
+      context.apply_global_filter(obj)
     end
 
     def render_to_output_buffer(context, output)
@@ -142,25 +140,6 @@ module Liquid
       parsed_args
     end
 
-    def taint_check(context, obj)
-      return if Template.taint_mode == :lax
-      return unless obj.tainted?
-
-      @markup =~ QuotedFragment
-      name = Regexp.last_match(0)
-
-      error               = TaintedError.new("variable '#{name}' is tainted and was not escaped")
-      error.line_number   = line_number
-      error.template_name = context.template_name
-
-      case Template.taint_mode
-      when :warn
-        context.warnings << error
-      when :error
-        raise error
-      end
-    end
-
     class ParseTreeVisitor < Liquid::ParseTreeVisitor
       def children
         [@node.name] + @node.filters.flatten

liquid.gemspec

@@ -27,6 +27,6 @@ Gem::Specification.new do |s|
 
   s.require_path = "lib"
 
-  s.add_development_dependency('rake', '~> 11.3')
+  s.add_development_dependency('rake', '~> 13.0')
   s.add_development_dependency('minitest')
 end

test/integration/drop_test.rb

@@ -49,10 +49,6 @@ class ProductDrop < Liquid::Drop
     ContextDrop.new
   end
 
-  def user_input
-    (+"foo").taint
-  end
-
   protected
 
   def callmenot
@@ -114,34 +110,6 @@ class DropsTest < Minitest::Test
     assert_equal('  ', tpl.render!('product' => ProductDrop.new))
   end
 
-  if taint_supported?
-    def test_rendering_raises_on_tainted_attr
-      with_taint_mode(:error) do
-        tpl = Liquid::Template.parse('{{ product.user_input }}')
-        assert_raises TaintedError do
-          tpl.render!('product' => ProductDrop.new)
-        end
-      end
-    end
-
-    def test_rendering_warns_on_tainted_attr
-      with_taint_mode(:warn) do
-        tpl     = Liquid::Template.parse('{{ product.user_input }}')
-        context = Context.new('product' => ProductDrop.new)
-        tpl.render!(context)
-        assert_equal [Liquid::TaintedError], context.warnings.map(&:class)
-        assert_equal "variable 'product.user_input' is tainted and was not escaped", context.warnings.first.to_s(false)
-      end
-    end
-
-    def test_rendering_doesnt_raise_on_escaped_tainted_attr
-      with_taint_mode(:error) do
-        tpl = Liquid::Template.parse('{{ product.user_input | escape }}')
-        tpl.render!('product' => ProductDrop.new)
-      end
-    end
-  end
-
   def test_drop_does_only_respond_to_whitelisted_methods
     assert_equal("", Liquid::Template.parse("{{ product.inspect }}").render!('product' => ProductDrop.new))
     assert_equal("", Liquid::Template.parse("{{ product.pretty_inspect }}").render!('product' => ProductDrop.new))
@@ -281,7 +249,7 @@ class DropsTest < Minitest::Test
   end
 
   def test_invokable_methods
-    assert_equal(%w(to_liquid catchall user_input context texts).to_set, ProductDrop.invokable_methods)
+    assert_equal(%w(to_liquid catchall context texts).to_set, ProductDrop.invokable_methods)
     assert_equal(%w(to_liquid scopes_as_array loop_pos scopes).to_set, ContextDrop.invokable_methods)
     assert_equal(%w(to_liquid size max min first count).to_set, EnumerableDrop.invokable_methods)
     assert_equal(%w(to_liquid max min sort count first).to_set, RealEnumerableDrop.invokable_methods)

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/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/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/render_tag_test.rb

@@ -42,34 +42,6 @@ class RenderTagTest < Minitest::Test
     assert_template_result('', "{% assign snippet = 'should not be visible' %}{% render 'snippet' %}")
   end
 
-  if taint_supported?
-    def test_render_sets_the_correct_template_name_for_errors
-      Liquid::Template.file_system = StubFileSystem.new('snippet' => '{{ unsafe }}')
-
-      with_taint_mode :error do
-        template = Liquid::Template.parse('{% render "snippet", unsafe: unsafe %}')
-        context  = Context.new('unsafe' => (+'unsafe').tap(&:taint))
-        template.render(context)
-
-        assert_equal [Liquid::TaintedError], template.errors.map(&:class)
-        assert_equal 'snippet', template.errors.first.template_name
-      end
-    end
-
-    def test_render_sets_the_correct_template_name_for_warnings
-      Liquid::Template.file_system = StubFileSystem.new('snippet' => '{{ unsafe }}')
-
-      with_taint_mode :warn do
-        template = Liquid::Template.parse('{% render "snippet", unsafe: unsafe %}')
-        context  = Context.new('unsafe' => (+'unsafe').tap(&:taint))
-        template.render(context)
-
-        assert_equal [Liquid::TaintedError], context.warnings.map(&:class)
-        assert_equal 'snippet', context.warnings.first.template_name
-      end
-    end
-  end
-
   def test_render_does_not_mutate_parent_scope
     Liquid::Template.file_system = StubFileSystem.new('snippet' => '{% assign inner = 1 %}')
     assert_template_result('', "{% render 'snippet' %}{{ inner }}")
@@ -155,7 +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
@@ -165,7 +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

@@ -176,7 +176,7 @@ 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)
@@ -215,7 +215,7 @@ class TemplateTest < Minitest::Test
 
   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)
@@ -361,56 +361,4 @@ 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
-
-  unless taint_supported?
-    def test_taint_mode
-      assert_raises(NotImplementedError) do
-        Template.taint_mode = :warn
-      end
-    end
-  end
 end

test/test_helper.rb

@@ -32,10 +32,6 @@ module Minitest
     def fixture(name)
       File.join(File.expand_path(__dir__), "fixtures", name)
     end
-
-    def self.taint_supported?
-      Object.new.taint.tainted?
-    end
   end
 
   module Assertions
@@ -93,14 +89,6 @@ module Minitest
       Liquid::StrainerFactory.instance_variable_set(:@global_filters, original_global_filters)
     end
 
-    def with_taint_mode(mode)
-      old_mode = Liquid::Template.taint_mode
-      Liquid::Template.taint_mode = mode
-      yield
-    ensure
-      Liquid::Template.taint_mode = old_mode
-    end
-
     def with_error_mode(mode)
       old_mode = Liquid::Template.error_mode
       Liquid::Template.error_mode = mode
@@ -110,10 +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/context_unit_test.rb

@@ -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/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/static_registers_unit_test.rb

@@ -52,6 +52,12 @@ class StaticRegistersUnitTest < Minitest::Test
       static_register.fetch(:d)
     end
     assert_equal("default", static_register.fetch(:d, "default"))
+
+    result = static_register.fetch(:d) { "default" }
+    assert_equal("default", result)
+
+    result = static_register.fetch(:d, "default 1") { "default 2" }
+    assert_equal("default 2", result)
   end
 
   def test_key