* first action! (#1)

node_modules/p-cancelable/index.js

@@ -0,0 +1,103 @@
+'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;