Correct misclassification of .js.erb files

[CHTJonas]

Change the language classification of *.js.erb files from HTML+ERB to JavaScript+ERB. I think I've covered all the relevant bases but let me know if there's something I can correct - thanks for taking the time to review! 😄

Description

Previously JavaScript files containing embedded Ruby syntax were misclassified as HTML+ERB. This PR would correct this by classifying such source code files as JavaScript+ERB and grouping under the parent JavaScript language.

Motivation for this is that JavaScript files meant for client-side execution in response to an AJAX request in a Rails application are listed under HTML when running github-linguist --breakdown.

Checklist:

• I am associating a language with a new file extension.
  • The new extension is used in hundreds of repositories on GitHub.com
    • Search results for each extension:
      • https://github.com/search?utf8=%E2%9C%93&type=Code&ref=searchresults&q=extension%3Aerb+escape_javascript+NOT+nothack
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • https://edgeguides.rubyonrails.org/working_with_javascript_in_rails.html#a-simple-example
    • Sample license(s):
      • MIT
  • I have included a change to the heuristics to distinguish my language from others using the same extension.

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[pchaigno]

Thanks for the pull request and sorry for the delay in reviewing!

I left two comments related to syntax highlighting below.

For other reviewers: I think there is a large enough corpus of these files on GitHub to mandate support: extension:erb filename:js.

[CHTJonas]

Thanks for the comments @pchaigno! Syntax highlighting updated now to use JavaScript now.

I wasn't sure whether tm_scope should be source.js (same as JavaScript language proper) or whether I should add something like text.js.erb to the grammars.yml file to match what HTML+ERB and NetLinx+ERB do?

[pchaigno]

I wasn't sure whether tm_scope should be source.js (same as JavaScript language proper) or whether I should add something like text.js.erb to the grammars.yml file to match what HTML+ERB and NetLinx+ERB do?

The grammar.yml should not be manually updated so source.js is fine. If we're using JavaScript for both the TextMate scope and the CodeMirror grammar, we might as well add the extension to the list of JavaScript extensions. It would achieve the exact same effect.

[CHTJonas]

I was considering that, but I think(?) listing separately does allow some benefits eg. when searching you can restrict the scope to JavaScript+ERB as opposed to all JavaScript, such as this example with HTML+ERB.

[stale]

This pull request has been automatically marked as stale because it has not had recent activity, and will be closed if no further activity occurs. If this pull request was overlooked, forgotten, or should remain open for any other reason, please reply here to call attention to it and remove the stale status. Thank you for your contributions.

[CHTJonas]

Did you have any thoughts on the above RE: whether to keep the .js.erb extension separate or just add it to the list of JS extensions @pchaigno?

[stale]

This pull request has been automatically marked as stale because it has not had recent activity, and will be closed if no further activity occurs. If this pull request was overlooked, forgotten, or should remain open for any other reason, please reply here to call attention to it and remove the stale status. Thank you for your contributions.