Merge branch 'main' into fix/custom_tag_rendering

* main:
  implement whitespace control to comment tag
  fix parsing comment tag delimiter
  fix parsing nested comment tag with extra strings
  fix parsing comment tag delimiter with extra strings
  fix parsing comment block body inside a liquid tag
  allow incomplete tags inside a comment tag
  refactor comment tag unit test to use test helper
  add a quirky comment tag unit test
  clean up comment tag body parsing
  don't parse nodes inside a comment tag

lib/liquid/block_body.rb

@@ -6,6 +6,7 @@ module Liquid
   class BlockBody
     LiquidTagToken      = /\A\s*(#{TagName})\s*(.*?)\z/o
     FullToken           = /\A#{TagStart}#{WhitespaceControl}?(\s*)(#{TagName})(\s*)(.*?)#{WhitespaceControl}?#{TagEnd}\z/om
+    FullTokenPossiblyInvalid = /\A(.*)#{TagStart}#{WhitespaceControl}?\s*(\w+)\s*(.*)?#{WhitespaceControl}?#{TagEnd}\z/om
     ContentOfVariable   = /\A#{VariableStart}#{WhitespaceControl}?(.*?)#{WhitespaceControl}?#{VariableEnd}\z/om
     WhitespaceOrNothing = /\A\s*\z/
     TAGSTART            = "{%"

lib/liquid/tags/comment.rb

@@ -15,6 +15,8 @@ module Liquid
   #   {% endcomment %}
   # @liquid_syntax_keyword content The content of the comment.
   class Comment < Block
+    TAG_DELIMITER = /\A(.*)#{TagStart}#{WhitespaceControl}?\s*(endcomment)\s*(\s.*)?#{WhitespaceControl}?#{TagEnd}\z/om
+
     def render_to_output_buffer(_context, output)
       output
     end
@@ -25,6 +27,74 @@ module Liquid
     def blank?
       true
     end
+
+    private
+
+    def parse_body(body, tokenizer)
+      if parse_context.depth >= MAX_DEPTH
+        raise StackLevelError, "Nesting too deep"
+      end
+
+      parse_context.depth += 1
+      comment_tag_depth = 1
+
+      begin
+        # Consume tokens without creating child nodes.
+        # The children tag doesn't require to be a valid Liquid except the comment and raw tag.
+        # The child comment and raw tag must be closed.
+        while (token = tokenizer.send(:shift))
+          tag_name = if tokenizer.for_liquid_tag
+            next if token.empty? || token.match?(BlockBody::WhitespaceOrNothing)
+
+            tag_name_match = BlockBody::LiquidTagToken.match(token)
+
+            next if tag_name_match.nil?
+
+            tag_name_match[1]
+          elsif TAG_DELIMITER.match?(token)
+            # aggressively match comment delimiter
+            "endcomment"
+          elsif token =~ BlockBody::FullToken && Regexp.last_match(2) == "comment"
+            # aggressively match comment tag
+            "comment"
+          else
+            tag_name_match = BlockBody::FullTokenPossiblyInvalid.match(token)
+
+            next if tag_name_match.nil?
+
+            tag_name_match[2]
+          end
+
+          case tag_name
+          when "raw"
+            parse_raw_tag_body(tokenizer)
+          when "comment"
+            comment_tag_depth += 1
+          when "endcomment"
+            comment_tag_depth -= 1
+
+            if comment_tag_depth.zero?
+              parse_context.trim_whitespace = (token[-3] == WhitespaceControl)
+              return false
+            end
+          end
+        end
+
+        raise_tag_never_closed(block_name)
+      ensure
+        parse_context.depth -= 1
+      end
+
+      false
+    end
+
+    def parse_raw_tag_body(tokenizer)
+      while (token = tokenizer.send(:shift))
+        return if token =~ BlockBody::FullTokenPossiblyInvalid && "endraw" == Regexp.last_match(2)
+      end
+
+      raise_tag_never_closed("raw")
+    end
   end
 
   Template.register_tag('comment', Comment)

lib/liquid/tags/raw.rb

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

test/unit/tags/comment_tag_unit_test.rb

@@ -0,0 +1,169 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class CommentTagUnitTest < Minitest::Test
+  def test_comment_inside_liquid_tag
+    assert_template_result("", <<~LIQUID.chomp)
+      {% liquid
+        if 1 != 1
+        comment
+        else
+          echo 123
+        endcomment
+        endif
+      %}
+    LIQUID
+  end
+
+  def test_does_not_parse_nodes_inside_a_comment
+    assert_template_result("", <<~LIQUID.chomp)
+      {% comment %}
+        {% if true %}
+        {% if ... %}
+        {%- for ? -%}
+        {% while true %}
+        {%
+          unless if
+        %}
+        {% endcase %}
+      {% endcomment %}
+    LIQUID
+  end
+
+  def test_allows_incomplete_tags_inside_a_comment
+    assert_template_result("", <<~LIQUID.chomp)
+      {% comment %}
+        {% assign foo = "1"
+      {% endcomment %}
+    LIQUID
+
+    assert_template_result("", <<~LIQUID.chomp)
+      {% comment %}
+        {% comment %}
+          {% invalid
+        {% endcomment %}
+      {% endcomment %}
+    LIQUID
+
+    assert_template_result("", <<~LIQUID.chomp)
+      {% comment %}
+      {% {{ {%- endcomment %}
+    LIQUID
+  end
+
+  def test_child_comment_tags_need_to_be_closed
+    assert_template_result("", <<~LIQUID.chomp)
+      {% comment %}
+        {% comment %}
+          {% comment %}{%    endcomment     %}
+        {% endcomment %}
+      {% endcomment %}
+    LIQUID
+
+    assert_raises(Liquid::SyntaxError) do
+      assert_template_result("", <<~LIQUID.chomp)
+        {% comment %}
+          {% comment %}
+            {% comment %}
+          {% endcomment %}
+        {% endcomment %}
+      LIQUID
+    end
+  end
+
+  def test_child_raw_tags_need_to_be_closed
+    assert_template_result("", <<~LIQUID.chomp)
+      {% comment %}
+        {% raw %}
+          {% endcomment %}
+        {% endraw %}
+      {% endcomment %}
+    LIQUID
+
+    assert_raises(Liquid::SyntaxError) do
+      Liquid::Template.parse(<<~LIQUID.chomp)
+        {% comment %}
+          {% raw %}
+          {% endcomment %}
+        {% endcomment %}
+      LIQUID
+    end
+  end
+
+  def test_error_line_number_is_correct
+    template = Liquid::Template.parse(<<~LIQUID.chomp, line_numbers: true)
+      {% comment %}
+        {% if true %}
+      {% endcomment %}
+      {{ errors.standard_error }}
+    LIQUID
+
+    output = template.render('errors' => ErrorDrop.new)
+    expected = <<~TEXT.chomp
+
+      Liquid error (line 4): standard error
+    TEXT
+
+    assert_equal(expected, output)
+  end
+
+  def test_comment_tag_delimiter_with_extra_strings
+    assert_template_result(
+      '',
+      <<~LIQUID.chomp,
+        {% comment %}
+          {% comment %}
+          {% endcomment
+          {% if true %}
+          {% endif %}
+        {% endcomment %}
+      LIQUID
+    )
+  end
+
+  def test_nested_comment_tag_with_extra_strings
+    assert_template_result(
+      '',
+      <<~LIQUID.chomp,
+        {% comment %}
+          {% comment
+            {% assign foo = 1 %}
+          {% endcomment
+          {% assign foo = 1 %}
+        {% endcomment %}
+      LIQUID
+    )
+  end
+
+  def test_ignores_delimiter_with_extra_strings
+    assert_template_result(
+      '',
+      <<~LIQUID.chomp,
+        {% if true %}
+          {% comment %}
+            {% commentXXXXX %}wut{% endcommentXXXXX %}
+          {% endcomment %}
+        {% endif %}
+      LIQUID
+    )
+  end
+
+  def test_delimiter_can_have_extra_strings
+    assert_template_result('', "{% comment %}123{% endcomment xyz %}")
+    assert_template_result('', "{% comment %}123{% endcomment\txyz %}")
+    assert_template_result('', "{% comment %}123{% endcomment\nxyz %}")
+    assert_template_result('', "{% comment %}123{% endcomment\n   xyz  endcomment %}")
+  end
+
+  def test_with_whitespace_control
+    assert_template_result("Hello!", "      {%- comment -%}123{%- endcomment -%}Hello!")
+    assert_template_result("Hello!", "{%- comment -%}123{%- endcomment -%}     Hello!")
+    assert_template_result("Hello!", "      {%- comment -%}123{%- endcomment -%}     Hello!")
+
+    assert_template_result("Hello!", <<~LIQUID.chomp)
+      {%- comment %}Whitespace control!{% endcomment -%}
+      Hello!
+    LIQUID
+  end
+end