如何创建文件流并异步写入流？

如何解决如何创建文件流并异步写入流？

我是TypeScript / JavaScript和Node的新手。
现在，我正在尝试创建文件流并编写“ Hello！”。异步传输到流中。

./keycloak/bin/jboss-cli.sh --connect --command='/subsystem=logging/console-handler=CONSOLE:change-log-level(level=DEBUG)'
./keycloak/bin/jboss-cli.sh --connect --command='/subsystem=logging/root-logger=ROOT:change-root-log-level(level=DEBUG)'
./keycloak/bin/jboss-cli.sh --connect --command='/subsystem=logging/logger=org.keycloak:write-attribute(name=level,value=DEBUG)'

此代码确实创建了#!/usr/bin/env node import fs from 'fs'; function createStream(filePath: string): Promise<fs.WriteStream> { return new Promise<fs.WriteStream>((resolve,reject) => { const out = fs.createWriteStream(filePath); out.on('close',() => { console.log(filePath + ' closed'); resolve(out); }); out.on('error',(err: any) => { console.log(filePath + ' ' + err); reject(err); }); }); } createStream('/tmp/test.txt').then((out:fs.WriteStream) => { console.log(out); out.write('Hello!'); out.end(); }) ，但是什么也没打印出来，并且文件为空。
此代码有什么问题？

解决方法

由于const gulp = require('gulp'),sass = require('gulp-sass'),autoprefixer = require('gulp-autoprefixer'),cleanCSS = require('gulp-clean-css'),concatCss = require('gulp-concat-css'),uglify = require('gulp-uglify'),pipeline = require('readable-stream').pipeline,concat = require('gulp-concat'),terser = require('gulp-terser'),newer = require('gulp-newer'); gulp.task('sass',() => gulp.src('./src/scss/*.scss') .pipe(newer('./src/scss/*.scss')) .pipe(sass()) .pipe(concatCss("style.css")) .pipe(cleanCSS()) .pipe(gulp.dest('./dist/css')) ); gulp.task('jsfiles',function () { return pipeline( gulp.src('./src/js/*.js'),newer('./src/js/*.js'),concat('vendor.js'),uglify({ compress:true }),gulp.dest('./dist/js') ); }); gulp.task('default',() => { gulp.watch(['./src/scss/*.scss','./src/js/*.js'],gulp.series('sass','jsfiles')); }) 的创建是同步的，因此您无需使用fs.WriteStream来解决承诺。只需直接调用fs.createWriteStream()并将实例传递给您的函数即可创建一个承诺，该承诺将在流关闭或错误时解决：

#!/usr/bin/env node

import fs from 'fs';
import stream from 'stream';

function promisify(s: stream.Stream): Promise<void> {
  return new Promise<void>((resolve,reject) => {
    const onClose = () => {
      s.off('error',onError);
      resolve();
    };
    const onError = (error: Error) => {
      s.off('close',onClose);
      reject(error);
    };

    s.once('close',onClose);
    s.once('error',onError);
  });
}

const out = fs.createWriteStream('/tmp/test.txt');

promisify(out).then(() => {
  console.log('Done');
});

out.write('Hello!');
out.end();