Resolve no-unused-vars, no-undef eslint warnings

[andyhot]

No description provided.

[rwjblue]

Does this resolve all of the warnings for no-unused-vars / no-undef? If it does, we should consider having those rules trigger errors so that we do not regress in future iterations...

[andyhot]

I'll push an update to this PR that handles all of them (including the tests).

I'm setting no-unused-vars to ["error", { "args": "none" }] so that it doesn't report unused arguments but I plan to explore this in an upcoming commit (or PR)

[andyhot]

I'd need some guidance on how to continue.

• After aef5325 i see only 2 remaining eslint errors - https://github.com/emberjs/ember.js/blob/master/packages/loader/lib/index.js#L43 and https://github.com/emberjs/ember.js/blob/master/packages/loader/lib/index.js#L51 (both Move function declaration to function body root no-inner-declarations)
  Perhaps we want that error suppressed there?
• I set no-unused-vars': ["error", { "args": "after-used" }] to see the unused arguments issues. I now get 57 errors (and in fact 392 more in the tests). Most of those 57 errors are of the type
  filterBy(key, value) { return this.filter(iter.apply(this, arguments)); }
  and I am not in favor of 'fixing' those. It looks like keeping no-unused-vars to ["error", { "args": "none" }] works best for ember.js

[homu]

☔ The latest upstream changes (presumably #14985) made this pull request unmergeable. Please resolve the merge conflicts.

[homu]

☔ The latest upstream changes (presumably #15014) made this pull request unmergeable. Please resolve the merge conflicts.

[andyhot]

This has long become obsolete