ESLint v7

[bradzacher]

ESLint has v7 released.
https://eslint.org/blog/2020/05/eslint-v7.0.0-released

I went through the change list, and below are a list of changes I think we need to look into for full support:

Dependencies:

• Breaking: drop Node.js 8 support (refs eslint/rfcs#44) (#12700)
  • Tracked locally in NodeJS v8 EOL at begin of Jan 2020 #1420

Tests:

• Breaking: RuleTester Improvements (refs eslint/rfcs#25) (#12955)
  • This will likely break many of our tests.
• Breaking: Test with an unknown error property should fail in RuleTester (#12096)
  • Could break some of our tests.
• Update: Allow testing Suggestions with data in RuleTester (fixes #12606) (#12635)
  • Didn't know this wasn't checked! Might break some of our tests.

Functionality:

• Breaking: some rules recognize bigint literals (fixes #11803) (#12701)
  • Will want to make sure our extension is still compatible
• Breaking: Add new rules to eslint:recommended (fixes #12911) (#12920)
  • We will want to review it so we can update ours accordingly Changes to the recommended sets for 3.0.0 #1423

Extension rules:

• Message IDs
  • Chore: Refactor to use messageId in a number of rules (#12715)
  • Chore: use ids for messages (#12859)
• Update: Improve report location for space-before-function-paren (#13128)
• Fix: func-call-spacing "never" reports wrong message (fixes #13190) (#13193)
• no-magic-numbers
  • Update: stricter array index check in no-magic-numbers (fixes #12845) (#12851)
  • Update: fix no-magic-numbers false negative with ignoreArrayIndexes (#12805)
• no-implied-eval
  • Update: support globalThis in no-implied-eval (fixes #12670) (#13105)
  • Update: consider env in no-implied-eval (fixes #12733) (#12757)
• no-extra-parens
  • Breaking: Check assignment targets in no-extra-parens (#12490)
  • Update: report double extra parens in no-extra-parens (fixes #12127) (#12697)
  • Update: fix no-extra-parens CallExpression#callee false negatives (#12743)
  • Fix: no-extra-parens export default sequence expression false positive (#13096)
  • Fix: fix inconsistently works option in no-extra-parens (fixes #12717) (#12843)
• no-empty-function
  • Update: Improve report location for no-empty-function (refs #12334) (#13121)
  • Fix: added async in allow method in no-empty-function (fixes #12768) (#13036)

Docs:

• Breaking: lint overrides files (fixes #10828, refs eslint/rfcs#20) (#12677)
  • You no longer need --ext if you specify overrides: { files: ["*.ts"], ... }
  • Do we want to update our docs for this - we could now generally advise that you use an overrides for ts files?
    • Unsure if that's actually better than using the cli flag.
• Update: no-void add an option to allow void as a statement (#12613)
  • We can update the docs for no-floating-promises now

[bradzacher]

This change has been released to NPM on the rc-v3 tag.
It is part of the upcoming major release: https://github.com/typescript-eslint/typescript-eslint/releases/tag/v3.0.0-alpha.23

We'll probably let that soak for a week or so to give people time to test it before the full release.

[Sparticuz]

Looks like it's tagged rc-v3