don't parse nodes inside a comment tag

Co-authored-by: Alex Coco <[email protected]>

test/unit/tags/comment_tag_unit_test.rb

@@ -0,0 +1,82 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class CommentTagUnitTest < Minitest::Test
+  def test_does_not_parse_nodes_inside_a_comment
+    template = Liquid::Template.parse(<<~LIQUID.chomp, line_numbers: true)
+      {% comment %}
+        {% if true %}
+        {% if ... %}
+        {%- for ? -%}
+        {% while true %}
+        {%
+          unless if
+        %}
+        {% endcase %}
+      {% endcomment %}
+    LIQUID
+
+    assert_equal("", template.render)
+  end
+
+  def test_child_comment_tags_need_to_be_closed
+    template = Liquid::Template.parse(<<~LIQUID.chomp, line_numbers: true)
+      {% comment %}
+        {% comment %}
+          {% comment %}{%    endcomment     %}
+        {% endcomment %}
+      {% endcomment %}
+    LIQUID
+
+    assert_equal("", template.render)
+
+    assert_raises(Liquid::SyntaxError) do
+      Liquid::Template.parse(<<~LIQUID.chomp, line_numbers: true)
+        {% comment %}
+          {% comment %}
+            {% comment %}
+          {% endcomment %}
+        {% endcomment %}
+      LIQUID
+    end
+  end
+
+  def test_child_raw_tags_need_to_be_closed
+    template = Liquid::Template.parse(<<~LIQUID.chomp, line_numbers: true)
+      {% comment %}
+        {% raw %}
+          {% endcomment %}
+        {% endraw %}
+      {% endcomment %}
+    LIQUID
+
+    assert_equal("", template.render)
+
+    assert_raises(Liquid::SyntaxError) do
+      Liquid::Template.parse(<<~LIQUID.chomp, line_numbers: true)
+        {% 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
+end