eslint: make --fix remove unused imports

[phillco]

I noticed that eslint --fix didn't remove unused imports and eslint src --ext ts complained with a warning about an existing unused one:

$ eslint src --ext ts
.../src/core/commandVersionUpgrades/canonicalizeAndValidateCommand.ts
  1:10  warning  'window' is defined but never used. Allowed unused vars must match /^_/u  @typescript-eslint/no-unused-vars

I imagine this is because most people are fixing this up using the Visual Studio Code action, but it's nice to have everything working from the command line. Also JetBrains will only do it if eslint --fix does, hence my motivation :)

This adds the configuration such that eslint src --ext ts --fix removed unused imports, and fixes the existing unused imports in the codebase. Let me know if I made a mistake.

Checklist

• I have added tests
• I have updated the docs and cheatsheet

[pokey]

Neat! I am definitely supportive of this direction

I think we need to tweak the ignore comments for most of these unused imports, though; see inline comment.

Also see #640; would be good to get this into pre-commit if easy

[phillco]

Yeah, I definitely did take a look at #640 :). A quick naive implementation had it making a bunch of changes, so I stopped for now.

Will update the tagging on the existing imports.

[phillco]

I've tagged the existing unused imports with unused-imports/no-unused-imports and restored them, and updated the branch. Will take a look at https://github.com/import-js/eslint-plugin-import next to see if it's better, but otherwise this version is ready to go.

[phillco]

From the meetup: we looked at https://github.com/import-js/eslint-plugin-import briefly but didn't see a rule for removing unused imports. no-unused-modules seems to be more about finding exports in your own modules that aren't used. @auscompgeek let me know if I missed it.

If there is, we can use it. Otherwise, this should be ready to merge and we can take a look at adding some of eslint-plugin-import's rules as a follow up change, as I imagine that would be valuable in their own right.

[phillco]

@auscompgeek @pokey can we merge this?

[pokey]

👍👍