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Name	Size	Permission	Date
index.d.ts	4.52 KB	-rw-r--r--	2021-11-13 16:54
index.js	2.18 KB	-rw-r--r--	2021-11-13 16:54
package.json	809 B	-rw-r--r--	2021-11-13 16:54

Rename

'use strict';

class CancelError extends Error {
	constructor(reason) {
		super(reason || 'Promise was canceled');
		this.name = 'CancelError';
	}

get isCanceled() {
		return true;
	}
}

class PCancelable {
	static fn(userFn) {
		return (...arguments_) => {
			return new PCancelable((resolve, reject, onCancel) => {
				arguments_.push(onCancel);
				// eslint-disable-next-line promise/prefer-await-to-then
				userFn(...arguments_).then(resolve, reject);
			});
		};
	}

constructor(executor) {
		this._cancelHandlers = [];
		this._isPending = true;
		this._isCanceled = false;
		this._rejectOnCancel = true;

this._promise = new Promise((resolve, reject) => {
			this._reject = reject;

const onResolve = value => {
				if (!this._isCanceled || !onCancel.shouldReject) {
					this._isPending = false;
					resolve(value);
				}
			};

const onReject = error => {
				this._isPending = false;
				reject(error);
			};

const onCancel = handler => {
				if (!this._isPending) {
					throw new Error('The `onCancel` handler was attached after the promise settled.');
				}

this._cancelHandlers.push(handler);
			};

Object.defineProperties(onCancel, {
				shouldReject: {
					get: () => this._rejectOnCancel,
					set: boolean => {
						this._rejectOnCancel = boolean;
					}
				}
			});

return executor(onResolve, onReject, onCancel);
		});
	}

then(onFulfilled, onRejected) {
		// eslint-disable-next-line promise/prefer-await-to-then
		return this._promise.then(onFulfilled, onRejected);
	}

catch(onRejected) {
		return this._promise.catch(onRejected);
	}

finally(onFinally) {
		return this._promise.finally(onFinally);
	}

cancel(reason) {
		if (!this._isPending || this._isCanceled) {
			return;
		}

this._isCanceled = true;

if (this._cancelHandlers.length > 0) {
			try {
				for (const handler of this._cancelHandlers) {
					handler();
				}
			} catch (error) {
				this._reject(error);
				return;
			}
		}

if (this._rejectOnCancel) {
			this._reject(new CancelError(reason));
		}
	}

get isCanceled() {
		return this._isCanceled;
	}
}

Object.setPrototypeOf(PCancelable.prototype, Promise.prototype);

module.exports = PCancelable;
module.exports.CancelError = CancelError;