Download a file on Node.js

To download a file on Node.js, you can use the built-in fs module and the https or http module to make a request to the server and save the response to a file.

Here's an example of how you can download a file using https module:

const https = require('https');
const fs = require('fs');

const fileUrl = 'https://example.com/file.pdf';
const filePath = './downloads/file.pdf';

const file = fs.createWriteStream(filePath);

https.get(fileUrl, (response) => {
  response.pipe(file);
  file.on('finish', () => {
    file.close();
    console.log('File downloaded successfully.');
  });
}).on('error', (err) => {
  fs.unlink(filePath, () => {
    console.error(`Error downloading file: ${err}`);
  });
});

In the above example, we first define the URL of the file we want to download and the path where we want to save the file. We then create a write stream to the file using the fs module.

Next, we make a https.get() request to the server, passing the file URL as the first argument and a callback function as the second argument. In the callback function, we pipe the response to the write stream and listen for the 'finish' event to close the file and log a success message.

If an error occurs while downloading the file, we delete the incomplete file using fs.unlink() and log an error message.