Parsing Error when using no-output erb tags in certain contexts

[gravitystorm]

Thanks for the plugin! I'm trying to get it running on our existing codebase, but I've run into a situation where most of our erb files don't parse. They contain code something similar to:

OSM = {
<% if something %>
  MATOMO: <%= Settings.matomo.to_json %>,
<% end %>
  MAX_REQUEST_AREA: <%= Settings.max_request_area.to_json %>
}

If I understand correctly, both <% %> and <%= %> tags get converted into the same placeholder - effectively {}. However, this leads to the parser error:

OSM = {
{}
  MATOMO: {},
{}
  MAX_REQUEST_AREA: {}
}

I can see that replacing the erb-output tags (e.g. <%= %>) with {} makes sense. But does the same hold true for the non-output tags like <% %>? Would it be better to use a different placeholder (e.g. just a comment with the hash etc) for these tags?

OSM = {
/* zero output placeholder comment */
  MATOMO: {},
/* zero output placeholder comment */
  MAX_REQUEST_AREA: {}
}

Sorry in advance if I'm overlooking anything here!

[Splines]

Hey, yes I think you're right on this. It's just that I didn't encounter this use case in our MaMpf codebase yet, so this scenario didn't come to my mind, so thanks for creating this issue.

I was a bit shocked that such a mature ecosystem as Rails has no Linter for .js.erb files available, see e.g. this post. So that's why I considered writing a plugin for ESLint in the first place. And just replacing everything by something simple as {} worked out quite fine (so far), that's the main reason I used that. It's a bit of a balancing act to counter every situation with the dummy string, see for example also this issue: eslint/eslint#18114. And then of course, my approach is limited with regards to indentation, this is the only really annoying thing, see the limitations.

I will try to implement your suggested change and see if it still works on our codebase or if this introduces some unexpected problems. But looks like a valid approach to me. This week is a bit packed, but next week I will probably get down to it.

[Splines]

I will soon create a release for this. Please note that in your mentioned commit where you've tried to incorporate the plugin, you did not yet set the reportUnusedDisableDirectives to "off". Without this, things won't work on your side. See the Readme.

[gravitystorm]

Thanks @Splines that's great (and quick!). And thank you for the tip about the configuration - I'd noticed that but focussed on the syntax error thing first. We'll get this sorted after the next release.

[Splines]

@gravitystorm You're welcome 😊 I've just released v2.1.1 on npm. Fingers crossed that it works for you now. At least the test case you've provided yields correct results.

[gravitystorm]

Yes, everything looks good to me! Thanks again.