Bug report

Bug description:

This violates the usual write() contract of returning the number of items written (for synchronous I/O) and also affects StreamReaderWriter.write() transitively.

In this case it seems trivial to just return the result of the called self.stream.write().

CPython versions tested on:

CPython main branch

Operating systems tested on:

No response

Linked PRs

• gh-134706: Return bytes written from codecs.Stream(Reader)Writer.write() #134708