Type inference of dynamic properties

[Nctdt]

Bug Report

🔎 Search Terms

union type, dynamic properties

🕗 Version & Regression Information

• This is the behavior in every version I tried

⏯ Playground Link

Playground link with relevant code

💻 Code

declare const bar: 'name' | 'age'
const obj = {
  any: 'any',
  [bar]: 'wow',
}

🙁 Actual behavior

const obj: {
    [x: string]: string;
    any: string;
}

🙂 Expected behavior

const obj: {
    name: string;
    any: string;
} | {
    age: string;
    any: string;
}

I think this is a predictable type.

[Nctdt]

I currently use type assertions.
Playground
The test is as follows:

declare const bar: 'name' | 'age'
declare const baz: 'my' | 'test'
const obj = {
  any: 'any',
  [bar]: 'bar',
  [baz]: 'baz',
} as C2
type T1<O, T, V> = O extends any
  ? T extends string | number | symbol
    ? {
        [C in T | keyof O]: C extends keyof O ? O[C] : V
      }
    : never
  : never
type C1 = T1<{ any: string }, typeof bar, string>
type C2 = T1<C1, typeof baz, string>

[jcalz]

Duplicate #13948, #21030