stream: update comment for needMoreData

[mcollina]

• Version: master
• Platform: all
• Subsystem: streams

node/lib/_stream_readable.js

Lines 304 to 315 in d37e59f

	// if it's past the high water mark, we can push in some more.
	// Also, if we have no data yet, we can stand some
	// more bytes. This is to work around cases where hwm=0,
	// such as the repl. Also, if the push() triggered a
	// readable event, and the user called read(largeNumber) such that
	// needReadable was set, then we ought to push more, so that another
	// 'readable' event will be triggered.
	function needMoreData(state) {
	return !state.ended &&
	(state.length < state.highWaterMark ||
	state.length === 0);
	}

comment is out of date (ref. #19613 (comment)).

Specifically it states:

I think that comment is actually wrong. It says

if it's past the high water mark, we can push in some more.

However it has a check (simplified) as:

return state.length < state.highWaterMark

Which will return true if we are below the watermark.

This would be a good issue for someone willing to learn more about streams.

[Xavier-J-Ortiz]

@mcollina I'd like to take this issue up. I do think I'd need some guidance and might have some followup questions while I wrap my head around the problem.

[mcollina]

Definitely. If that also result in one more unit test, even better!
Ping me if you have any questions!

[vsnehil92]

@mcollina, since there is no PR from 6 days, may I work on this issue? This is my first contribution so I would need some guidance.

[mcollina]

Sure, feel free to ping me in IRC or twitter any time.

[Xavier-J-Ortiz]

@mcollina - Apologies, something came up on my end.

@vsnehil92 - Feel free to work on this as I haven't had any time.

[lpinca]

Fixed by e76831b. Closing.