feat: support 'latest' as ecmaVersion

[fisker]

Ref eslint/eslint#14720

[typescript-eslint]

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[codecov]

Codecov Report

Merging #3710 (d93aec0) into master (fa35e22) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #3710      +/-   ##
==========================================
- Coverage   92.68%   92.67%   -0.02%     
==========================================
  Files         327      327              
  Lines       11352    11359       +7     
  Branches     3201     3205       +4     
==========================================
+ Hits        10522    10527       +5     
- Misses        369      370       +1     
- Partials      461      462       +1     

Flag	Coverage Δ
unittest	92.67% <100.00%> (-0.02%)	⬇️

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Impacted Files	Coverage Δ
packages/scope-manager/src/analyze.ts	68.96% <100.00%> (+2.29%)	⬆️
packages/eslint-plugin/src/util/isTypeReadonly.ts	94.20% <0.00%> (-2.82%)	⬇️
packages/eslint-plugin/src/rules/dot-notation.ts	92.30% <0.00%> (ø)
...ackages/experimental-utils/src/ts-eslint/Linter.ts	100.00% <0.00%> (ø)
...t-plugin/src/rules/prefer-reduce-type-parameter.ts	100.00% <0.00%> (ø)

[fisker]

Any chance this can get merged?

[bradzacher]

thanks! Two quikc comments

[bradzacher]

instead of letting this string trickle all the way down into here such that it needs to be handled differently - I think we should instead convert it to a number at the parser level.

This would be similar to what ESLint does for espree (they annoyingly do it within eslint itself...)

[fisker]

Handled latest in parser, used 1e8 like acorn and babel

[fisker]

I don't use typescript, I'm not sure how to fix the type check, can some one help?

[bradzacher]

tests/eslint-scope/map-ecma-version.test.ts:47:23 - error TS2322: Type 'EcmaVersion' is not assignable to type 'number | undefined'.
  Type '"latest"' is not assignable to type 'number | undefined'.

47   analyze(fakeNode, { ecmaVersion: ecmaVersion as EcmaVersion });
                         ~~~~~~~~~~~

The types in the test are wrong.
You've retyped ecmaVersion in the analyze options to be a number, but your test passes in a string.

[bradzacher]

Suggested change

	ecmaVersion?: number;
	ecmaVersion?: EcmaVersion;

[bradzacher]

you don't need/want this check any more

[fisker]

I don't have the knowledge to fix it.