/
DeferredPromise.ts
68 lines (65 loc) · 1.51 KB
/
DeferredPromise.ts
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import {TimeoutError} from '../common/Errors.js';
/**
* @internal
*/
export interface DeferredPromise<T> extends Promise<T> {
finished: () => boolean;
resolved: () => boolean;
resolve: (_: T) => void;
reject: (_: Error) => void;
}
/**
* @internal
*/
export interface DeferredPromiseOptions {
message?: string;
timeout?: number;
}
/**
* Creates and returns a promise along with the resolve/reject functions.
*
* If the promise has not been resolved/rejected within the `timeout` period,
* the promise gets rejected with a timeout error.
*
* @internal
*/
export function createDeferredPromise<T>({
message,
timeout = 5000,
}: DeferredPromiseOptions = {}): DeferredPromise<T> {
let isResolved = false;
let isRejected = false;
let resolver = (_: T): void => {};
let rejector = (_: Error) => {};
const taskPromise = new Promise<T>((resolve, reject) => {
resolver = resolve;
rejector = reject;
});
const timeoutId =
timeout > 0
? setTimeout(() => {
isRejected = true;
rejector(new TimeoutError(message));
}, timeout)
: undefined;
return Object.assign(taskPromise, {
resolved: () => {
return isResolved;
},
finished: () => {
return isResolved || isRejected;
},
resolve: (value: T) => {
if (timeoutId) {
clearTimeout(timeoutId);
}
isResolved = true;
resolver(value);
},
reject: (err: Error) => {
clearTimeout(timeoutId);
isRejected = true;
rejector(err);
},
});
}