Version

v21.6.2

Platform

Darwin x86_64

Subsystem

stream

What steps will reproduce the bug?

const { Readable, Writable } = require('stream');

const r = new Readable({
  read() {}
});

const w = new Writable({
  highWaterMark: 0,
  write(chunk, encoding, callback) {
    console.log(chunk.toString());
    callback();
  },
});

r.pipe(w);

r.push('hello');
r.push('world');
r.push(null);

How often does it reproduce? Is there a required condition?

Always

What is the expected behavior? Why is that the expected behavior?

In node v20.9.0 and earlier:

What do you see instead?

In node v20.10.0 and later, only the first chunk ever arrives at the destination:

Additional information

The issue is present on node v20.10.0, but is not present on v20.9.0. The issue is also present on v21.0.0.

A workaround is to use highWaterMark: 1.