feat: support ESLint 8.x

[MichaelDeBoey]

ESLint v8.0.0 is released 🎉

devDependency compatibility with ESLint 8:

• @babel/eslint-parser (Support ESLint 8.x babel/babel#13712)
  • Add ESLint 8 support to @babel/eslint-parser babel/babel#13782
  • v7.16.0
• @typescript-eslint/parser (Support for ESLint v8 typescript-eslint/typescript-eslint#3738)
  • feat: support ESLint v8 typescript-eslint/typescript-eslint#3737
  • chore: bump Node to ESLint 8.0 ranges typescript-eslint/typescript-eslint#3767
  • feat(eslint-plugin): [comma-dangle] align schema with ESLint v8 typescript-eslint/typescript-eslint#3768
  • feat: remove meta.docs.category from rules typescript-eslint/typescript-eslint#3800
  • feat: align class property representation with ESTree typescript-eslint/typescript-eslint#3806
  • feat: support PrivateIdentifier typescript-eslint/typescript-eslint#3808
  • feat(eslint-plugin): update recommended configs typescript-eslint/typescript-eslint#3809
  • v5.0.0
• eslint-config-canonical (Support ESLint 8.x eslint-config-canonical#32)
  • feat: support ESLint 8.x eslint-config-canonical#33
  • v32.0.0

---

BREAKING CHANGE: Requires ESLint@^7.0.0 || ^8.0.0

Closes #791

[brettz9]

Thanks very much for the report and draft PR.

check-examples will unfortunately not work due to our waiting on eslint/eslint#14745 (so that the ESLint constructor can indeed fully replace CLIEngine for our needs with the rule).

I think we can work around this for now by:

• Have the src/rules/checkExamples.js file immediately run something like the following if ESLint 8 is detected (and return):

      context.report({
        loc: {
          start: {
            column: 1,
            line: 1,
          },
        },
        message: `This rule cannot yet be supported for ESLint 8; you should either downgrade to ESLint 7 or disable this rule. The possibility for ESLint 8 support is being tracked at https://github.com/eslint/eslint/issues/14745`,
      });

• Adjust test/rules/index.js to avoid testing the rule when when ESLint 8 is detected
• Make a note of this under the check-examples documentation (adding a note to the top of /.README/rules/check-examples.md such as This rule currently does not work in ESLint 8 (we are waiting on [issue 14745](https://github.com/eslint/eslint/issues/14745)). and then running npm run create-readme to rebuild the main README).

Am a bit preoccupied these days, but I should be able to review if you (or someone) could assist with those changes.

[MichaelDeBoey]

@brettz9 I think I did everything you mentioned.

Let me know what you think of it!

[brettz9]

Thanks a lot. That mostly covered it. I've applied a few additional updates/fixes. Be sure to run npm i after pulling.

I've disabled linting in CI (and lint-staged) until eslint-config-canonical may be updated. (Since there is a mutual dependency between this project and that one, it will probably be good to have this project updated so it can target the updated one--then we can resume linting after that is updated.)

I checked the checkbox for @typescript-eslint/parser 5.0.0 as 5.0.0 is now released (and I guess the whole to-do for the parser is complete?).

There is one remaining problem though... Despite getting this working fine locally, for our ESLint 7 CI tests, we're still getting an error related to check-examples. I don't know if that means the CI environment isn't actually installing 7.0 there as it should or if it isn't properly detecting the version the same in these environments as it is on my machine (Mac).

[brettz9]

Looks like we have one remaining task now of getting the CI Node 17 environment (for which I'd like this PR to add support) updating to Python >=3.6.0

[gajus]

🎉 This PR is included in version 37.0.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

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