node.js - 如何将 .then 方法制作为 async.waterfall Node js

Question

我想将 .then Promise 方法更改为 async.waterfall

var readfile = require('./app.js')
var fileName = 'batch1.txt'
var fileName1 = 'batch2.txt'

readfile(fileName).then((message) => {
    readfile(fileName1).then((message1) => {
        console.log(message);
        console.log(message1);
    });
});

Answer 1

试试这个:

var readfile = require('./app.js')
var fileName = 'batch1.txt'
var fileName1 = 'batch2.txt'

readfile(fileName)
.then(() => readfile(fileName1) )
.then( (msg)=> console.log(msg));

或者您可以使用Promise.all

Promise.all([ readfile(fileName), readfile(fileName1) ]).then( ( results // Array ) =>{
    console.log(results[0]); // result of first promise
    console.log(results[1]); // result of second promise
});