stream: Transform questions

[ronag]

• What is the difference between _final and _flush?
• Is it allowed to override _read and _write and if so, what does it actually mean to override either of these?

[ronag]

For context I'm just trying to understand the semantics of Transform and understand the motivation for it.

It seems to me that the Transform stream should be implementing _final, _read and _write itself and only let the user provide _flush and _transform, otherwise the semantics/behaviour is very unclear.

[addaleax]

It seems to me that the Transform stream should be implementing _final, _read and _write itself and only let the user provide _flush and _transform, otherwise the semantics/behaviour is very unclear.

That would make sense to me, I think.

[ronag]

I've managed to significantly simplify the Transform implementation https://github.com/nxtedition/node/pull/10/files. However, it depends on #30597 first being merged so a PR will have to wait.