native-class-ext/lib/PromiseExt.js

js原生对象增加常用方法

(function(){
	const defineProperty = require('./defineProperty.js')
	if (typeof Promise.allSettled === "undefined") {
		/**
		 * 所有给定的Promise都实现或拒绝之后解析
		 * @param {Array} promises Promise数组
		 * @return {Array} 执行结果，顺序和promises一样， [{status: "rejected", reason: res}, {status: "fulfilled",value: res}]   
		 * */
		let allSettled = async function(promises) {
			let ret = [];
			for (var i = 0; i < promises.length; i++) {
				try {
					let res = await promises[i];
					ret[i] = {
						status: "fulfilled",
						value: res
					}
				} catch (e) {
					ret[i] = {
						status: "rejected",
						reason: e
					}
				}
			}
			return ret;
		}
		defineProperty(Promise, 'allSettled', allSettled);
	}
	
	if (typeof Promise.prototype.finally === 'undefined') {
		// 兼容低版本浏览器
		defineProperty(Promise.prototype, 'finally', function(onFinally) {
			return this.then(
				res => Promise.resolve(onFinally()).then(() => res),
				err => Promise.resolve(onFinally()).then(() => {
					throw err;
				})
			);
		});
	}
	
	/**
	 * 不抛异常的方式返回结果
	 * */
	let result = async function() {
		try {
			let res = await this;
			return {
				status: true,
				data: typeof res == 'boolean' ? res : (res || {})
			};
		} catch (e) {
			return {
				status: false,
				data: typeof e == 'boolean' ? e : (e || {})
			};
		}
	}
	defineProperty(Promise.prototype, '$result', result);
	
})()