104 lines
1.9 KiB
JavaScript
Executable File
104 lines
1.9 KiB
JavaScript
Executable File
'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 (...args) => {
|
|
return new PCancelable((resolve, reject, onCancel) => {
|
|
args.push(onCancel);
|
|
userFn(...args).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 => {
|
|
this._isPending = false;
|
|
resolve(value);
|
|
};
|
|
|
|
const onReject = error => {
|
|
this._isPending = false;
|
|
reject(error);
|
|
};
|
|
|
|
const onCancel = handler => {
|
|
this._cancelHandlers.push(handler);
|
|
};
|
|
|
|
Object.defineProperties(onCancel, {
|
|
shouldReject: {
|
|
get: () => this._rejectOnCancel,
|
|
set: bool => {
|
|
this._rejectOnCancel = bool;
|
|
}
|
|
}
|
|
});
|
|
|
|
return executor(onResolve, onReject, onCancel);
|
|
});
|
|
}
|
|
|
|
then(onFulfilled, onRejected) {
|
|
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;
|
|
}
|
|
|
|
if (this._cancelHandlers.length > 0) {
|
|
try {
|
|
for (const handler of this._cancelHandlers) {
|
|
handler();
|
|
}
|
|
} catch (error) {
|
|
this._reject(error);
|
|
}
|
|
}
|
|
|
|
this._isCanceled = true;
|
|
if (this._rejectOnCancel) {
|
|
this._reject(new CancelError(reason));
|
|
}
|
|
}
|
|
|
|
get isCanceled() {
|
|
return this._isCanceled;
|
|
}
|
|
}
|
|
|
|
Object.setPrototypeOf(PCancelable.prototype, Promise.prototype);
|
|
|
|
module.exports = PCancelable;
|
|
module.exports.default = PCancelable;
|
|
|
|
module.exports.CancelError = CancelError;
|