[method-signature-style] Cannot read property 'typeAnnotation' of undefined

[AriPerkkio]

Hello, I'm testing stability of well known community ESlint plugins with eslint-remote-tester. This ESLint plugin seems to contain a rule which causes linter to crash. ESlint rules should not crash in any condition since this makes all valid linting problems disappear. If this is a false flag please let me know.

• I have tried restarting my IDE and the issue persists.
• I have updated to the latest version of the packages.
• I have read the FAQ and my problem is not listed.

Repro

{
  "rules": {
   "@typescript-eslint/method-signature-style": "error"
  }
}

// An interface defining method which implicitly returns `any`
interface MyInterface {
    methodReturningImplicitAny();
}

Error report from ci/eslint-remote-tester-results/adobe_react-spectrum.md

Rule: method-signature-style

• Message: Cannot read property 'typeAnnotation' of undefined Occurred while linting <text>:25
• Path: adobe/react-spectrum/packages/@react-stately/color/src/useColorWheelState.ts
• Link

  readonly hue: number,
  setHue(value: number): void,

  increment(minStepSize?: number),
  decrement(minStepSize?: number),

  isDragging: boolean,
  setDragging(value: boolean): void
}

TypeError: Cannot read property 'typeAnnotation' of undefined
Occurred while linting <text>:25
    at getMethodReturnType (/<root-path-removed>/eslint-remote-tester/ci/node_modules/@typescript-eslint/eslint-plugin/dist/rules/method-signature-style.js:74:55)
    at Object.fix (/<root-path-removed>/eslint-remote-tester/ci/node_modules/@typescript-eslint/eslint-plugin/dist/rules/method-signature-style.js:163:48)
    at normalizeFixes (/<root-path-removed>/eslint-remote-tester/node_modules/eslint/lib/linter/report-translator.js:178:28)
    at /<root-path-removed>/eslint-remote-tester/node_modules/eslint/lib/linter/report-translator.js:347:49
    at Object.report (/<root-path-removed>/eslint-remote-tester/node_modules/eslint/lib/linter/linter.js:920:41)
    at TSMethodSignature (/<root-path-removed>/eslint-remote-tester/ci/node_modules/@typescript-eslint/eslint-plugin/dist/rules/method-signature-style.js:157:29)
    at /<root-path-removed>/eslint-remote-tester/node_modules/eslint/lib/linter/safe-emitter.js:45:58
    at Array.forEach (<anonymous>)
    at Object.emit (/<root-path-removed>/eslint-remote-tester/node_modules/eslint/lib/linter/safe-emitter.js:45:38)
    at NodeEventGenerator.applySelector (/<root-path-removed>/eslint-remote-tester/node_modules/eslint/lib/linter/node-event-generator.js:254:26)

Expected Result

ESLint rule should not crash.

Actual Result

TypeError: Cannot read property 'typeAnnotation' of undefined
Occurred while linting <text>:25
    at getMethodReturnType (/<root-path-removed>/eslint-remote-tester/ci/node_modules/@typescript-eslint/eslint-plugin/dist/rules/method-signature-style.js:74:55)

Additional Info

This is not blocking my development or anything. This was spotted on automated CI run: https://github.com/AriPerkkio/eslint-remote-tester/actions/runs/390047365

2020-11-29T19:20:45.9576188Z [WARN] adobe/react-spectrum crashed: method-signature-style

Versions

package	version
@typescript-eslint/eslint-plugin	4.9.0
@typescript-eslint/parser	4.9.0
TypeScript	4.0.2
ESLint	7.9.0
node	14.15.1