[WIP] Fix false positives in require-nan-check rule

[Copilot]

• Treat Number.isFinite(x) / isFinite(x) as validating
• Treat truthiness guards (if (x), if (!x), ternary test) on the tracked identifier as validating
• Update rule message text
• Add valid-case tests for all 4 reported patterns
• Verify the 4 grounded files are no longer flagged

• Fixes require-nan-check-after-env-numeric-parse: false positives on Number.isFinite() and truthiness NaN guards #50495

[Copilot]

Pull request overview

Extends NaN-validation detection for environment-derived numeric parsing.

Changes:

• Recognizes finite checks and direct truthiness guards.
• Updates diagnostics and adds grounded valid-case tests.

Show a summary per file

File	Description
require-nan-check-after-env-numeric-parse.ts	Expands validation detection.
require-nan-check-after-env-numeric-parse.test.ts	Tests finite and truthiness guards.

Review details

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Suppressed comments (2)

eslint-factory/src/rules/require-nan-check-after-env-numeric-parse.ts:131

• Validation is recorded by identifier text rather than by the tracked binding. A truthiness check on a same-named parameter or local in another scope can therefore clear the diagnostic for the parsed value—for example, const port = parseInt(process.env.PORT, 10); function f(port) { if (port) use(port); } use(port);. Resolve the test identifier to its scope variable/declarator and mark only that tracked binding as validated.

      if (expr.type === "Identifier") {
        validated.add(expr.name);

eslint-factory/src/rules/require-nan-check-after-env-numeric-parse.ts:113

• Number.isFinite is also accepted when Number is a locally shadowed object, so code such as const Number = { isFinite: () => true }; const n = parseInt(process.env.N, 10); Number.isFinite(n); incorrectly marks n validated. Require Number to resolve to the unshadowed global before accepting this call.

        callee.object.type === "Identifier" &&
        callee.object.name === "Number" &&
        !callee.computed &&
        callee.property.type === "Identifier" &&
        (callee.property.name === "isNaN" || callee.property.name === "isFinite")

• Files reviewed: 2/2 changed files
• Comments generated: 1
• Review effort level: Balanced

[github-actions]

Great work on fixing the false positives in the require-nan-check-after-env-numeric-parse rule! 🎯

This PR successfully extends validation detection to recognize Number.isFinite(), isFinite(), and truthiness guards (if (!x), if (x), ternary) as valid NaN checks, addressing all four grounded false positive patterns documented in #50495. The implementation mirrors the existing isIsNaNCall pattern cleanly and the test coverage validates all reported scenarios.

The diff is focused, the tests are comprehensive, and the PR message clearly describes the work done. Ready for merge! ✨

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[github-actions]

🎉 This pull request is included in a new release.

Release: v0.85.1