如何在 Node js 中正确关闭可写流？

Question

我对 javascript 还很陌生。我正在使用节点 js 可写流来编写 .txt 文件；它运行良好，但我无法理解如何正确关闭文件，因为只要程序是运行，它的内容就是空白的。更详细地说，我需要在写入该 .txt 文件后读取它，但这样做 returns 一个空缓冲区。

let myWriteStream = fs.createWriteStream("./filepath.txt");
myWriteStream.write(stringBuffer + "\n");    
myWriteStream.on('close', () => {
           console.log('close event emitted');
    });
myWriteStream.end();

// do things..
let data = fs.readFileSync("./filepath.txt").toString().split("\n");

好像是.end()方法发出的事件是在文件读取后触发的，导致读取为空。如果我放一个 while() 来等待事件被触发，这样我就可以确定流在读取之前关闭，程序将永远等待。你知道我做错了什么吗？

Answer 1

你遗漏了 2 件事，一个测试成功了那么你需要等待流完成事件

const { readFileSync, createWriteStream } = require('fs')

const stringBuffer = Buffer.from(readFileSync('index.js')
)
const filePath = "./filepath.txt"
const myWriteStream = createWriteStream(filePath)

let backPressureTest = false;
while (!backPressureTest) {
    backPressureTest = myWriteStream.write(stringBuffer + "\n");
}
myWriteStream.on('close', () => {
    console.log('close event emitted');
});
myWriteStream.on('finish', () => {
    console.log('finish event emitted');
    let data = readFileSync(filePath).toString().split("\n");
    console.log(data);
});

myWriteStream.end();

如何在 Node js 中正确关闭可写流？

How to properly close a writable stream in Node js?

node.js

nodejs-stream