`vitest/prefer-expect-type-of` autofix can produce non-typechecking `expectTypeOf(...).toBeFunction()` in TS tests

[Nick2bad4u]

@vitest/eslint-plugin rule vitest/prefer-expect-type-of suggests/autofixes:

expect(typeof value).toBe("function")

to

expectTypeOf(value).toBeFunction()

But in my setup this can fail TypeScript checking with:

TS2349: This expression is not callable.
Type 'ExpectFunction<unknown>' has no call signatures.

---

Environment

• @vitest/eslint-plugin: 1.6.11
• vitest: 4.1.0
• TypeScript: 5.9.3
• Node: 25.8.1
• OS: Windows 11

---

repro from repository code

if (firstSuggestion !== undefined) {
  expect(typeof firstSuggestion.fix).toBe("function");
}

When vitest/prefer-expect-type-of is enabled and autofix is applied, this becomes:

expectTypeOf(firstSuggestion.fix).toBeFunction();

Then TypeScript can fail with:

TS2349: This expression is not callable.
Type 'ExpectFunction<unknown>' has no call signatures.

---

Expected behavior

Autofix should only apply when the resulting assertion is type-safe, or skip autofix if it may break typechecking.

Actual behavior

Autofix/suggestion can lead to TS compile errors for valid runtime assertions.

Would you consider guarding the fixer for cases where expectTypeOf(...).toBeFunction() is not type-safe in the current typing context somehow?