Formatter: Keep herb:disable comments with their own anchor's line

[markokajzer]

reproduction

<% foo %> <%# herb:disable erb-no-unused-expressions %>
<% foo %> <%# herb:disable erb-no-unused-expressions %>

before

<% foo %> <%# herb:disable erb-no-unused-expressions %> <%# herb:disable erb-no-unused-expressions %>
<% foo %>

after

unchanged input.

<% foo %> <%# herb:disable erb-no-unused-expressions %>
<% foo %> <%# herb:disable erb-no-unused-expressions %>

cause

findOutputLineForHerbDisable re-attached each collected comment to the first output line containing the anchor's search text (<% foo %>, <div, …), so identical anchors all resolved to the first match. This also put a disable on a second <div> onto the first <div>.

fix

count how often the search text appears in the source before the anchor and pick that same occurrence in the output.

alternatives considered

• Record each anchor's output line while printing
  • probably the "cleanest" way, but requires a bunch of changes across a few files
  • was not sure if i should go down this route, open to feedback!

[markokajzer]

example where a more complex solution might be desired

with the above fix, the following still is not handled correctly

<%=foo%>
<%= foo %> <%# herb:disable some-rule %>

Output:

<%= foo %> <%# herb:disable some-rule %>
<%= foo %>

The fix assumes the search text appears the same number of times in the source and in the output, so it still misplaces the comment when the formatter rewrites an earlier identical ERB tag