Streams: readable stream does not get _construct called

[a0viedo]

• Version: v14.15.0
• Platform: Linux
• Subsystem: streams

What steps will reproduce the bug?

const { Readable } = require('stream');
class ReadStream extends Readable {
  constructor() {
    super();
  }
  _construct(cb) {
      console.log('_construct called');
      cb();
  }
  _read(n) {
  }
}

(new ReadStream()).on('data', ()=>{});

If I run the above with v14.15.0 nothing gets printed but on v15.0.1 I get "_construct called".

How often does it reproduce?

Always

What is the expected behavior?

_construct should be called

What do you see instead?

_construct is not called

Additional information

According to the docs this was added on v14.13.1

[lpinca]

The feature is not available on Node.js 14.x. I think the Added in: 14.13.1 info is incorrect.

[targos]

If the feature is not available on v14.x, this is still an issue because the documentation has it on that branch:
https://github.com/nodejs/node/blob/v14.x/doc/api/stream.md#readable_constructcallback
https://github.com/nodejs/node/blob/v14.x/doc/api/stream.md#writable_constructcallback

[lpinca]

Can't #36067 simply be backported to v14? Or do you want to keep this open until that happens?

[targos]

That PR just changes the version number. I think we should entirely remove that feature from the documentation in v14

[lpinca]

Ah yes you are right, it makes sense.