forked from sindresorhus/type-fest
-
Notifications
You must be signed in to change notification settings - Fork 0
/
promise-value.d.ts
29 lines (23 loc) · 1.05 KB
/
promise-value.d.ts
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
/**
Returns the type that is wrapped inside a `Promise` type.
If the type is a nested Promise, it is unwrapped recursively until a non-Promise type is obtained.
If the type is not a `Promise`, the type itself is returned.
@example
```
import {PromiseValue} from 'type-fest';
type AsyncData = Promise<string>;
let asyncData: PromiseValue<AsyncData> = Promise.resolve('ABC');
type Data = PromiseValue<AsyncData>;
let data: Data = await asyncData;
// Here's an example that shows how this type reacts to non-Promise types.
type SyncData = PromiseValue<string>;
let syncData: SyncData = getSyncData();
// Here's an example that shows how this type reacts to recursive Promise types.
type RecursiveAsyncData = Promise<Promise<string> >;
let recursiveAsyncData: PromiseValue<RecursiveAsyncData> = Promise.resolve(Promise.resolve('ABC'));
```
@category Utilities
*/
export type PromiseValue<PromiseType, Otherwise = PromiseType> = PromiseType extends Promise<infer Value>
? { 0: PromiseValue<Value>; 1: Value }[PromiseType extends Promise<unknown> ? 0 : 1]
: Otherwise;