Enable to infer the parameter's type correctly in this case. Why?

[TonyL1u]

TS version: 4.9.5
playground

type A1 = {
  key: 'id'
  type: 'date'
  format?: string
}

type A2 = {
  key: 'id'
  value?: (v: number) => any
}

type A3 = {
  key: 'name'
  value?: (v: string) => any
}

const obj: A1 | A2 | A3 = {
  key: 'id',
  value: v => v // Parameter 'v' implicitly has an 'any' type.(7006)
}

When I try to upgrade the TS version to 5.1.6, problem solved.
Is there any solutions to solve this problem without upgrading the TS version？

[MartinJohns]

You used the wrong issue template.

You can solve this problem by adding an explicit type annotation: (v: number) => v instead of v => v. Otherwise, really update your version, the one you use is almost three years old.

[TonyL1u]

You used the wrong issue template.

You can solve this problem by adding an explicit type annotation: (v: number) => v instead of v => v. Otherwise, really update your version, the one you use is almost three years old.

Our project is large and old, I'm afraid that upgrade the TS version may cause more unexpected type errors.
It seems that adding explicit type is the best way to solve this problem. Thank you for that!