Download file

download.mjs

import http from 'http';
import https from 'https';
import fs from 'fs';

export default async (url, dest) => {
  const protocol = url.indexOf('https') === 0 ? https : http;
  const fileStream = fs.createWriteStream(dest);
  return new Promise((resovle, reject) => {
    // http.IncomingMessage
    const request = protocol.get(url, (response) => {
      if (response.statusCode !== 200) {
        reject(new Error(`Download failed, code ${response.statusCode}`))
      }
      response.pipe(fileStream);
    });
    request.on('error', (error) => {
      reject(new Error(`Download failed, error message :  ${error.toString()}`))
    });
    // 无论是finish 还是 error fileStream都会自动close掉
    fileStream.on('finish', resovle); 
    fileStream.on('error', (error) => {
      reject(new Error(`Write file failed, error message :  ${error.toString()}`))
    });
  })
  
}

How to download a file with Node.js (without using third-party libraries)?