Pass stream as parameter to onFinish handler

I have a Node stream that can emit an error and can also emit content afterwards.

Example:

import {
  PassThrough
} from 'stream';

const passthrough = new stream.PassThrough();
passthrough.pipe(process.stdout);

passthrough.emit(new Error('boom'));

passthrough.write('foo');  // This gets written to process.stdout, even though an error was emitted.

I’d like to handle the error and continue. I can do so if we update pipeReadable to call onFinish with stream as a third parameter.

This way I can override error handling to write a new StreamError without ending.

[vqvu]

3.0.0-beta.3 released.

[vqvu]

Yes. I will do that when I merge the PR.