/*
189 - Awaited
-------
by Maciej Sikora (@maciejsikora) #easy #promise #built-in
### Question
If we have a type which is wrapped type like Promise. How we can get a type which is inside the wrapped type?
For example: if we have `Promise<ExampleType>` how to get ExampleType?
```ts
type ExampleType = Promise<string>
type Result = MyAwaited<ExampleType> // string
```
> This question is ported from the [original article](https://dev.to/macsikora/advanced-typescript-exercises-question-1-45k4) by [@maciejsikora](https://github.com/maciejsikora)
> View on GitHub: https://tsch.js.org/189
*/
/* _____________ Your Code Here _____________ */
// your answers
// your answers
type MyAwaited<T> = T extends Promise<infer P> ? P extends Promise<any> ? MyAwaited<P> : P : never;
/* _____________ Test Cases _____________ */
import type { Equal, Expect } from '@type-challenges/utils'
type X = Promise<string>
type Y = Promise<{ field: number }>
type Z = Promise<Promise<string | number>>
type Z1 = Promise<Promise<Promise<string | boolean>>>
type T = { then: (onfulfilled: (arg: number) => any) => any }
type cases = [
Expect<Equal<MyAwaited<X>, string>>,
Expect<Equal<MyAwaited<Y>, { field: number }>>,
Expect<Equal<MyAwaited<Z>, string | number>>,
Expect<Equal<MyAwaited<Z1>, string | boolean>>,
Expect<Equal<MyAwaited<T>, number>>,
]
// @ts-expect-error
type error = MyAwaited<number>
/* _____________ Further Steps _____________ */
/*
> Share your solutions: https://tsch.js.org/189/answer
> View solutions: https://tsch.js.org/189/solutions
> More Challenges: https://tsch.js.org
*/
标签:https,_____________,ts,Awaited,number,Promise,Expect,体操,type
From: https://blog.51cto.com/u_15283585/6193331