marcoroth · marcoroth · Nov 9, 2025 · Nov 9, 2025
diff --git a/lib/herb/ast/helpers.rb b/lib/herb/ast/helpers.rb
@@ -21,6 +21,17 @@ def erb_comment?(opening)
       def erb_output?(opening)
         opening.include?("=")
       end
+
+      #: (Herb::AST::ERBContentNode) -> bool
+      def inline_ruby_comment?(node)
+        return false unless node.is_a?(Herb::AST::ERBContentNode)
+        return false if erb_comment?(node.tag_opening&.value || "")
+
+        content = node.content&.value || ""
+        stripped = content.lstrip
+
+        stripped.start_with?("#") && node.location.start.line == node.location.end.line
+      end
     end
   end
 end
diff --git a/lib/herb/engine/compiler.rb b/lib/herb/engine/compiler.rb
@@ -162,6 +162,8 @@ def visit_cdata_node(node)
       end
 
       def visit_erb_content_node(node)
+        return if inline_ruby_comment?(node)
+
         process_erb_tag(node)
       end
 

diff --git a/sig/herb/ast/helpers.rbs b/sig/herb/ast/helpers.rbs
diff --git a/test/engine/erb_comments_test.rb b/test/engine/erb_comments_test.rb
@@ -0,0 +1,83 @@
+# frozen_string_literal: true
+
+require_relative "../test_helper"
+require_relative "../snapshot_utils"
+require_relative "../../lib/herb/engine"
+
+module Engine
+  class ERBCommentsTest < Minitest::Spec
+    include SnapshotUtils
+
+    test "inline ruby comment on same line" do
+      template = %(<% if true %><% # Comment here %><% end %>)
+
+      assert_compiled_snapshot(template)
+    end
+
+    test "inline ruby comment with newline" do
+      template = "<% if true %><% # Comment here %>\n<% end %>"
+
+      assert_compiled_snapshot(template)
+    end
+
+    test "inline ruby comment between code" do
+      template = %(<% if true %><% # Comment here %><%= "hello" %><% end %>)
+
+      assert_compiled_snapshot(template)
+    end
+
+    test "inline ruby comment before and between code" do
+      template = %(<% # Comment here %><% if true %><% # Comment here %><%= "hello" %><% end %>)
+
+      assert_compiled_snapshot(template)
+    end
+
+    test "inline ruby comment with spaces" do
+      template = %(<%  # Comment %> <% code = "test" %><%= code %>)
+
+      assert_compiled_snapshot(template)
+    end
+
+    test "inline ruby comment multiline" do
+      template = "<% # Comment\nmore %> <% code = \"test\" %><%= code %>"
+
+      assert_compiled_snapshot(template)
+    end
+
+    test "evaluation: inline ruby comment on same line" do
+      template = %(<% if true %><% # Comment here %><% end %>)
+
+      assert_evaluated_snapshot(template)
+    end
+
+    test "evaluation: inline ruby comment with newline" do
+      template = "<% if true %><% # Comment here %>\n<% end %>"
+
+      assert_evaluated_snapshot(template)
+    end
+
+    test "evaluation: inline ruby comment between code" do
+      template = %(<% if true %><% # Comment here %><%= "hello" %><% end %>)
+
+      assert_evaluated_snapshot(template)
+    end
+
+    test "evaluation: inline ruby comment before and between code" do
+      template = %(<% # Comment here %><% if true %><% # Comment here %><%= "hello" %><% end %>)
+
+      assert_evaluated_snapshot(template)
+    end
+
+    test "evaluation: inline ruby comment with spaces" do
+      template = %(<%  # Comment %> <% code = "test" %><%= code %>)
+
+      assert_evaluated_snapshot(template)
+    end
+
+    test "evaluation: inline ruby comment multiline" do
+      template = "<% # Comment\nmore %> <% code = \"test\" %><%= code %>"
+
+      assert_evaluated_snapshot(template, { more: "ignored" })
+    end
+  end
+end
diff --git a/test/engine/evaluation_test.rb b/test/engine/evaluation_test.rb
@@ -398,5 +398,41 @@ class EvaluationTest < Minitest::Spec
 
       assert_evaluated_snapshot(template, {}, { escape: false })
     end
+
+    test "inline ruby comment on same line" do
+      template = %(<% if true %><% # Comment here %><% end %>)
+
+      assert_evaluated_snapshot(template, {}, { escape: false })
+    end
+
+    test "inline ruby comment with newline" do
+      template = "<% if true %><% # Comment here %>\n<% end %>"
+
+      assert_evaluated_snapshot(template, {}, { escape: false })
+    end
+
+    test "inline ruby comment between code" do
+      template = %(<% if true %><% # Comment here %><%= "hello" %><% end %>)
+
+      assert_evaluated_snapshot(template, {}, { escape: false })
+    end
+
+    test "inline ruby comment before and between code" do
+      template = %(<% # Comment here %><% if true %><% # Comment here %><%= "hello" %><% end %>)
+
+      assert_evaluated_snapshot(template, {}, { escape: false })
+    end
+
+    test "inline ruby comment with spaces" do
+      template = %(<%  # Comment %> <% code = "test" %><%= code %>)
+
+      assert_evaluated_snapshot(template, {}, { escape: false })
+    end
+
+    test "inline ruby comment multiline" do
+      template = "<% # Comment\nmore %> <% code = \"test\" %><%= code %>"
+
+      assert_evaluated_snapshot(template, { more: "ignored" }, { escape: false })
+    end
   end
 end
diff --git a/...ents_test/test_0001_inline_ruby_comment_on_same_line_ece56a54ce9835acc67012583c42fc01.txt b/...ents_test/test_0001_inline_ruby_comment_on_same_line_ece56a54ce9835acc67012583c42fc01.txt
diff --git a/...ents_test/test_0002_inline_ruby_comment_with_newline_32dd50121c8e2af22b8a7e5efd92940f.txt b/...ents_test/test_0002_inline_ruby_comment_with_newline_32dd50121c8e2af22b8a7e5efd92940f.txt
diff --git a/...ents_test/test_0003_inline_ruby_comment_between_code_987d6e126382f02311aa0c1a0e0007bc.txt b/...ents_test/test_0003_inline_ruby_comment_between_code_987d6e126382f02311aa0c1a0e0007bc.txt
diff --git a/...est_0004_inline_ruby_comment_before_and_between_code_d6e28172fd69bf4538744950bffb2848.txt b/...est_0004_inline_ruby_comment_before_and_between_code_d6e28172fd69bf4538744950bffb2848.txt
diff --git a/...ments_test/test_0005_inline_ruby_comment_with_spaces_a1f69e41bb63eacbc881533c704e17a4.txt b/...ments_test/test_0005_inline_ruby_comment_with_spaces_a1f69e41bb63eacbc881533c704e17a4.txt
diff --git a/...omments_test/test_0006_inline_ruby_comment_multiline_1dc1e842d2fb5a2484c2e2fa0eca3678.txt b/...omments_test/test_0006_inline_ruby_comment_multiline_1dc1e842d2fb5a2484c2e2fa0eca3678.txt
diff --git a/...est_0007_evaluation_inline_ruby_comment_on_same_line_da1ad954cfb3b204db6e91dd6fa35de7.txt b/...est_0007_evaluation_inline_ruby_comment_on_same_line_da1ad954cfb3b204db6e91dd6fa35de7.txt
diff --git a/...est_0008_evaluation_inline_ruby_comment_with_newline_3519273b500925a720622d82288e0a31.txt b/...est_0008_evaluation_inline_ruby_comment_with_newline_3519273b500925a720622d82288e0a31.txt
diff --git a/...est_0009_evaluation_inline_ruby_comment_between_code_2788ca7a784e1295299a8d85ec9e396d.txt b/...est_0009_evaluation_inline_ruby_comment_between_code_2788ca7a784e1295299a8d85ec9e396d.txt
diff --git a/...aluation_inline_ruby_comment_before_and_between_code_13d746f9eef6690df9a609b4349a5189.txt b/...aluation_inline_ruby_comment_before_and_between_code_13d746f9eef6690df9a609b4349a5189.txt
diff --git a/...test_0011_evaluation_inline_ruby_comment_with_spaces_403e802d2a1c4f738b359fc3eee74053.txt b/...test_0011_evaluation_inline_ruby_comment_with_spaces_403e802d2a1c4f738b359fc3eee74053.txt
diff --git a/...t/test_0012_evaluation_inline_ruby_comment_multiline_c4d3ea038c11a5575430ca4b14abff47.txt b/...t/test_0012_evaluation_inline_ruby_comment_multiline_c4d3ea038c11a5575430ca4b14abff47.txt
diff --git a/...tion_test/test_0025_inline_ruby_comment_on_same_line_ad303bca1e8d22f5b16ec13f3c664241.txt b/...tion_test/test_0025_inline_ruby_comment_on_same_line_ad303bca1e8d22f5b16ec13f3c664241.txt
diff --git a/...tion_test/test_0026_inline_ruby_comment_with_newline_9abf0cb2099f40dfd7f4dfd3bfe1cc76.txt b/...tion_test/test_0026_inline_ruby_comment_with_newline_9abf0cb2099f40dfd7f4dfd3bfe1cc76.txt
diff --git a/...tion_test/test_0027_inline_ruby_comment_between_code_846a700430f96166237a051e3fca1bed.txt b/...tion_test/test_0027_inline_ruby_comment_between_code_846a700430f96166237a051e3fca1bed.txt
diff --git a/...est_0028_inline_ruby_comment_before_and_between_code_033a23daedac7be2427e58914b665c0f.txt b/...est_0028_inline_ruby_comment_before_and_between_code_033a23daedac7be2427e58914b665c0f.txt
diff --git a/...ation_test/test_0029_inline_ruby_comment_with_spaces_c05d8f81793b59bea0ce93cf959bcfbe.txt b/...ation_test/test_0029_inline_ruby_comment_with_spaces_c05d8f81793b59bea0ce93cf959bcfbe.txt
diff --git a/...luation_test/test_0030_inline_ruby_comment_multiline_d65c4c66f63611e90c0ea96b74af1ce4.txt b/...luation_test/test_0030_inline_ruby_comment_multiline_d65c4c66f63611e90c0ea96b74af1ce4.txt
diff --git a/...on_test/test_0009_comment_before_content_compilation_2b3c4e3c244db77468813a7472298e82.txt b/...on_test/test_0009_comment_before_content_compilation_2b3c4e3c244db77468813a7472298e82.txt
-Original file line number
+Diff line change
@@ Expand Up / @@ -162,6 +162,8 @@ def visit_cdata_node(node) @@
           end
           def visit_erb_content_node(node)
+            return if inline_ruby_comment?(node)
             process_erb_tag(node)
           end
@@ Expand Down @@