Autofix corrupts multi-line <% ... %> blocks by stripping the opening tag

[darronschall]

I'm seeing an issue where Layout/LeadingEmptyLines autocorrect deletes the <% delimiter and breaks the template, using: erb_lint 0.9.0, rubocop 1.84.2, ruby 4.0.2

Save this five-line file as bug.html.erb:

<%
  bar = 1
  baz = 2
%>
<p><%= bar + baz %></p>

(e.g. printf '<%%\n bar = 1\n baz = 2\n%%>\n<p><%%= bar + baz %%></p>\n' > bug.html.erb)

Run bundle exec erb_lint bug.html.erb (with standard-erb-lint / the default Rubocop-backed ruleset, in particular Layout/LeadingEmptyLines enabled as autocorrectable).

It reports:

Layout/LeadingEmptyLines: Unnecessary blank line at the beginning of the source.
In file: bug.html.erb:2

Layout/TrailingWhitespace: Trailing whitespace detected.
In file: bug.html.erb:1

2 error(s) were found in ERB files

After autofixing (bundle exec erb_lint -a bug.html.erb) the now-4-line file reads:

bar = 1
  baz = 2
%>
<p><%= bar + baz %></p>

The opening <% delimiter has been removed. bar = 1 and baz = 2 are now literal HTML text, the closing %> is orphaned, and the template raises undefined local variable or method 'bar' at render time.

Expected: the autofix should leave multi-line <% ... %>blocks alone when the "leading empty line" it detects is the newline immediately after the opening <% delimiter.

Workaround: keep Ruby inside <% %> on a single line per statement so RuboCop's Layout cops have nothing to rewrite across the ERB boundary.

[darronschall]

I think this is a duplicate of #331 and potentially fixed by #413