node.js - 如何在 Node.js 中的异步函数上正确使用 Promise？

Question

我在 Node 中有一个异步函数，它读取一个文本文件，将整个文件放入一个字符串中，在每个新行处分割字符串，将它们放入一个数组中并随机返回一个。这里我实现了一个新的 Promise 函数来处理它:

exports.readTextFileAndReturnRandomLine = function readTextFile(file)
{
    //reads text file as string, splits on new line and inserts into array, returns random array element
    return new Promise((resolve, reject) =>
    {
        var fs = require('fs');
        var textFile = fs.readFile(file, 'utf8', (err, data) =>
        {
            if (err)
            {
                return reject(err);
            }
            else
            {
                var array = data.toString().split("\n");
                var response = array[Math.floor(Math.random() * array.length)];
                return resolve(response);
            }
        });
    });
}

这是函数正在读取的文本文件:

Hello there, 
Howdy, 
I will remember your name, 
Thanks for telling me, 
Hi 
Noted, 
Thanks 
Well hello there 
Nice to meet you 
The pleasure is all mine, 
Nice name,

现在在我的根 Node (app.js)中，我像这样调用该函数:

intents.matches('RememberName', [
    function (session, args, next) {
        var nameEntity = builder.EntityRecognizer.findEntity(args.entities, 'name');
        if (!nameEntity)
        {
            builder.Prompts.text(session, "Sorry, didn't catch your name. What is it?");
        } else 
        {
            next({ response: nameEntity.entity });
        }
    },
    function (session, results) {
        if (results.response)
        {         
            fileReader.readTextFileAndReturnRandomLine('./text/remembername.txt').then(function(value) {
                console.log(value + ", " + results.response);
            }).catch(function(reason) {
                console.log(reason);
            });
        }
        else
        {
            session.send("Ok");
        }
    }
]);

问题是 value 和 name 变量没有按照我输入的顺序打印到控制台。这是我的 实际输出:

my name is chris
, Chrisfor telling me,
my name is Chris
, Chris
my name is Chris
, Chris
my name is Chris
, Chrishere,
my name is Chris
, Chrisfor telling me,
my name is Chris
, Chrisasure is all mine,
my name is Chris
, Chris
my name is Chris
, Chris
my name is Chris
, Chrisllo there

这是我的预期输出:

my name is Chris
Hello there, Chris
my name is Chris
Howdy, Chris
my name is Chris
Nice to meet you Chris
my name is Chris
Nice name, Chris

我相信这与所有事情的同步性有关，但我一生都无法弄清楚它是什么。

Answer 1

结果是字符返回'\r'被从文本文件带入字符串中。将 .trim() 方法应用于 response 解决了问题。