Support for comments inside ERB

[johansenja]

Background

• I am using https://github.com/Shopify/erb-lint to lint my .html.erb files, which applies rubocop rules to them
• There are some known violations which I want to skip, and can do successfully by including the appropriate rubocop:disable comment at the end of the line, eg:

  <% if a > 0 # rubocop:disable Style/NumericPredicate %>

• I am also using Brakeman (which I believe uses this parser) to check erb files, but once there are comments inside the erb tags, the file is no longer parseable so it's no longer checked

Issue

This code:

<script>
  // ok
  const a = <%= 1 %>;

  // not ok
  const b = <%= 1 # hello %>;

  // ok
  <% if true %>;
    const c = true;
  <% end%>

  // not ok
  <% if true # hello %>;
    const d = true;
  <% end%>
</script>

leads to this parsing error when running brakeman

== Errors ==

Error: app/views/comments_in_erb.html.erb:8 :: parse error on value "ok" (tIDENTIFIER) Could not parse app/views/comments_in_erb.html.erb
Location: Could not parse <snip>/app/views/comments_in_erb.html.erb

Expected behaviour

I would expect %> after a # to terminate the comment and the tag; currently it seems like %> is parsed as being part of the comment

Working reproduction

You can see the issue here from this repo if you check it out and run brakeman - but sorry I don't have a non brakeman-specific reproduction https://github.com/johansenja/brakeman-erb-test/

[johansenja]

Closing because it actually is a syntax error and my editor misled me 😶‍🌫️ 🤦🏻