in transform stream transform method, `callback(null, null)` doesn't end stream but `this.push(null); callback()` does

Version

latest main branch

Platform

irrelevant

Subsystem

stream

What steps will reproduce the bug?

https://nodejs.org/api/stream.html#transform-transformchunk-encoding-callback

callback(null, null) doesn't end stream but this.push(null); callback() does

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

Always

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

callback(null, null) and this.push(null); callback() have the same effect (the stream ends).

What do you see instead?

callback(null, null) is different from this.push(null); callback()

Additional information

https://github.com/nodejs/node/blob/main/lib/internal/streams/transform.js#L177-L179

Would it be possible to change this to the following?

if (val !== undefined) {
  this.push(val)
}

Start in lib/internal/streams/transform.js at lines 177-179 and compare the documented Transform callback behavior with the existing stream implementation. Reproduce the difference between callback(null, null) and this.push(null); callback(), then inspect the relevant stream tests. Done means both forms consistently end the stream as described.