What's the difference between .pipe and pipeline on streams

Question

I found two different ways to pipe streams in node.js

Well known .pipe() method of a stream

https://nodejs.org/api/stream.html#stream_readable_pip

Answer 1

TL;DR - You better want to use pipeline

What's pipeline?

From the docs: A module method to pipe between streams forwarding errors and properly cleaning up and provide a callback when the pipeline is complete.

What's the motivation for using pipeline?

❌ Let's take a look at the following code:

const { createReadStream } = require('fs');
const { createServer } = require('http');
const server = createServer(
  (req, res) => {
    createReadStream(__filename).pipe(res);
  }
);

server.listen(3000);

What's wrong here? If the response will quit or the client closes the connection - then the read stream is not closed or destroy which leads to a memory leak.

✅So if you use pipeline, it would close all other streams and make sure that there are no memory leaks.

const { createReadStream } = require('fs');
const { createServer } = require('http');
const { pipeline } = require('stream');

const server = createServer(
  (req, res) => {
    pipeline(
      createReadStream(__filename),
      res,
      err => {
        if (err)
          console.error('Pipeline failed.', err);
        else
          console.log('Pipeline succeeded.');
      }
    );
  }
);

server.listen(3000);