Question

如果我的项目经常使用Promise，那么在编写函数时解决所有参数的promises是个好主意吗？例如，

function foo (arg1, arg2, arg3) {
    // do stuff with arg1, arg2, arg3
}

let pArg1 = getArg1Async();
let pArg2 = pArg1.then(calcArg2Async);
let pArg3 = getArg3Async();

let p = Promise.join(pArg1, pArg2, pArg3, foo);

变为

function foo(pArg1, pArg2, pArg3) {
    return Promise.join(pArg1, pArg2, pArg3, function(arg1, arg2, arg3) {
        // do stuff with arg1, arg2, arg3
    });
}

let pArg1 = getArg1Async();
let pArg2 = pArg1.then(calcArg2Async);
let pArg3 = getArg3Async();

let p = foo(pArg1, pArg2, pArg3);

Answer 1

这通常被称为＆＃34;提升＆＃34;一个方法。它是一种有用且已知的技术，你可以轻松地编写一个帮助你的帮助器：

function lift(fn){
    return function(){
       return Promise.all.call(this, arguments).then(fn);
    }
}

或现代节点＆＃34;现代节点＆＃34;并忽略this：

const lift = fn => (...args) => Promise.all(args).then(fn)

可以让你这样做：

var lifted = lift(myFn);
// fn will run when the promises resolve 
// and return a promise for the value.
var res = lifted(promise1, promise2);

在编写函数时解决所有参数的promise是个好主意吗？

1 个答案: