Created
February 17, 2021 03:17
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A hook that takes a promise and throws it according to the Suspense API
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| interface PromiseCachePending { | |
| promise: Promise<void>; | |
| } | |
| interface PromiseCacheResolved<T> { | |
| promise: Promise<void>; | |
| result: T; | |
| } | |
| interface PromiseCacheError { | |
| promise: Promise<void>; | |
| error: any; | |
| } | |
| type PromiseCache<T> = | |
| | PromiseCachePending | |
| | PromiseCacheResolved<T> | |
| | PromiseCacheError; | |
| const PROMISE_CACHE = new WeakMap<Promise<any>, PromiseCache<any>>(); | |
| /** | |
| * This is a hook that takes a promise and throws it according to the Suspense API | |
| * | |
| * @note This is a bit of a hack since this API is really low level and the full version of Suspense isn't released yet | |
| */ | |
| export default function awaitPromise<T>(promise: Promise<T>): T { | |
| let promiseCache: PromiseCache<T> | undefined = PROMISE_CACHE.get(promise); | |
| if (promiseCache) { | |
| if ('error' in promiseCache) { | |
| throw promiseCache.error; | |
| } | |
| if ('result' in promiseCache) { | |
| return promiseCache.result; | |
| } | |
| throw promiseCache.promise; | |
| } | |
| promiseCache = { | |
| promise: promise | |
| .then((result) => { | |
| Object.assign(promiseCache, { | |
| result, | |
| }); | |
| }) | |
| .catch((error) => { | |
| Object.assign(promiseCache, { | |
| error, | |
| }); | |
| }), | |
| }; | |
| PROMISE_CACHE.set(promise, promiseCache); | |
| throw promiseCache.promise; | |
| } |
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