fix(eslint-plugin): [no-misused-promises] factor thenable returning function overload signatures

[JoshuaKGoldberg]

PR Checklist

• Addresses an existing issue: fixes [no-misused-promises] false positives with overloaded function #4609
• That issue was marked as accepting prs
• Steps in CONTRIBUTING.md were taken

Overview

Previously the rule checked for any function overload signature that had a void-returning function for each parameter. Those parameters were then considered unsafe for thenable-returning functions.

In an ideal world we would use the type checker's getResolvedSignature API to grab the specific type signature used for the call instead. However, TypeScript selects the first matching signature, causing it to select one with the () => void parameter before the () => Promise<void> parameter is seen. microsoft/TypeScript#48077

Instead, now we no longer consider any parameter index unsafe if a signature can have a thenable-returning function for it. 😞

[typescript-eslint]

Thanks for the PR, @JoshuaKGoldberg!

typescript-eslint is a 100% community driven project, and we are incredibly grateful that you are contributing to that community.

The core maintainers work on this in their personal time, so please understand that it may not be possible for them to review your work immediately.

Thanks again!

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✅ Successfully ran 48 targets

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• Node 16.x - nx test @typescript-eslint/parser
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[codecov]

Codecov Report

Merging #4620 (252e3d9) into main (fabfc2b) will increase coverage by 2.00%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #4620      +/-   ##
==========================================
+ Coverage   92.41%   94.41%   +2.00%     
==========================================
  Files         350      151     -199     
  Lines       12059     8239    -3820     
  Branches     3430     2626     -804     
==========================================
- Hits        11144     7779    -3365     
+ Misses        642      262     -380     
+ Partials      273      198      -75     

Flag	Coverage Δ
unittest	94.41% <100.00%> (+2.00%)	⬆️

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

Impacted Files	Coverage Δ
...gin/src/rules/naming-convention-utils/validator.ts	95.54% <100.00%> (+0.02%)	⬆️
...ges/eslint-plugin/src/rules/no-misused-promises.ts	98.72% <100.00%> (+0.08%)	⬆️
...-internal/src/rules/no-typescript-estree-import.ts
packages/scope-manager/src/lib/es2017.object.ts
...ils/src/ast-utils/eslint-utils/ReferenceTracker.ts
packages/type-utils/src/getContextualType.ts
packages/utils/src/eslint-utils/nullThrows.ts
packages/utils/src/json-schema.ts
packages/scope-manager/src/lib/es2019.string.ts
...s/utils/src/ast-utils/eslint-utils/astUtilities.ts
... and 191 more

[bradzacher]

two more good test cases would be

interface ItLike {
  (name: string, callback: () => void): void;
}
interface ItLike {
  (name: string, callback: () => Promise<void>): void;
}
declare const it: ItLike;
it('', async () => {});

interface ItLike {
  (name: string, callback: () => Promise<void>): void;
}
interface ItLike {
  (name: string, callback: () => void): void;
}
declare const it: ItLike;
it('', async () => {});

because weirdly declaration merged signatures are evaluated in reverse order!

[JoshuaKGoldberg]

(GitHub auto-dismissed the approval)