fix(experimental-utils): support immutable members

[rafaelss95]

This PR is basically to provide support for immutable in some other members/functions besides of #3830.

[typescript-eslint]

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[rafaelss95]

PS 1: I tried to change Range from:

typescript-eslint/packages/ast-spec/src/base/Range.ts

Line 6 in 8218055

export type Range = [number, number];

to:

export type Range = readonly [number, number]; 

but it didn't work as it actually needs to be mutated in places like:

typescript-eslint/packages/typescript-estree/src/convert.ts

Line 168 in 9524424

result.range[0] = varToken!.getStart(this.ast);

So in this case I opted out for just typing the necessary functions as Readonly<AST.Range>.

PS 2: The lint failure seems to be unrelated to this change.
Since Array.isArray doesn't work properly with readonly T[] as reported in microsoft/TypeScript#17002, I used the type annotation in no-magic-numbers to avoid the no-unsafe-assignment report.

[codecov]

Codecov Report

Merging #3844 (0606673) into main (475caa4) will increase coverage by 0.15%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #3844      +/-   ##
==========================================
+ Coverage   93.33%   93.49%   +0.15%     
==========================================
  Files         152      192      +40     
  Lines        8014     8672     +658     
  Branches     2568     2683     +115     
==========================================
+ Hits         7480     8108     +628     
- Misses        180      351     +171     
+ Partials      354      213     -141     

Flag	Coverage Δ
unittest	93.49% <100.00%> (+0.15%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...kages/eslint-plugin/src/rules/no-empty-function.ts	80.00% <ø> (ø)
...ges/experimental-utils/src/ts-eslint/RuleTester.ts	100.00% <ø> (ø)
...ckages/eslint-plugin/src/rules/no-magic-numbers.ts	84.31% <100.00%> (+1.96%)	⬆️
packages/eslint-plugin/src/rules/array-type.ts	97.18% <0.00%> (-1.33%)	⬇️
packages/eslint-plugin/src/rules/brace-style.ts	95.34% <0.00%> (ø)
packages/eslint-plugin/src/rules/no-redeclare.ts	91.89% <0.00%> (ø)
...ackages/eslint-plugin/src/rules/no-extra-parens.ts	90.41% <0.00%> (ø)
...ackages/eslint-plugin/src/util/getWrappingFixer.ts	100.00% <0.00%> (ø)
...kages/eslint-plugin/src/rules/naming-convention.ts	81.09% <0.00%> (ø)
... and 101 more

[rafaelss95]

This PR was accidentally closed earlier and I had forgotten to reopen it.

[bradzacher]

One change - otherwise LGTM
Thanks for your work!

[bradzacher]

This would be a breaking change because it's not uncommon for people to do getAncestors().reverse()

Also - it isn't necessary because getAncestors returns a new array each invocation:
https://github.com/eslint/eslint/blob/d867f8100737bb82742debee2b5dc853c5f07c91/lib/linter/linter.js#L789-L797

[bradzacher]

LGTM - thanks for this!

[bradzacher]

the lint error is actually legit.
repro

Found this TS issue: microsoft/TypeScript#17002
It's a TS bug :(

Which I see you already found and mentioned above!!

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