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doc: Piping multiple streams to the same Writable stream might not end #36544
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This isn't really a problem with the documentation I would say, it seems to be caused by a bug introduced in #35348, lib/internal/streams/readable.js, that causes a pipe to be paused initially when the writable buffer needs draining. The problem is that the readable is just never resumed so it gets stuck and fails.
A simple solution would be to add a drain listener on dest after pausing src, like so: https://gist.github.com/HomerSp/07ec63dacf49aac5f55a62b7c09dc313Maybe this is supposed to be done automatically, but it just isn't? I can't see anything related to this though, so I'm not sure.
Yea. It's a bug. The drain handler is added lazily in the
ondatahandler which will never get invoked since it's paused.The fix should probably be something like:
index a004ce20d0..1afa3a2b29 100644 --- a/lib/internal/streams/readable.js +++ b/lib/internal/streams/readable.js @@ -794,6 +794,8 @@ Readable.prototype.pipe = function(dest, pipeOpts) { if (dest.writableNeedDrain === true) { if (state.flowing) { src.pause(); + ondrain = pipeOnDrain(src, dest); + dest.on('drain', ondrain); } } else if (!state.flowing) { debug('pipe resume');
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on May 22, 2026
📗 API Reference Docs Problem
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Description
Concise explanation of the problem
The documentation for
readable.pipe()reads:So when we open a Writable stream and then pipe multiple Readable streams into this Writable stream; the stream becomes full/congested and needs to drain but then we pipe more Readable streams into this stream. This seems to sometimes cause a Readable stream to not end and thus does not pipe its data to the Writable stream.
Bug in electron/asar explaining the issue electron/asar#210.
Since electron/asar does this in basically a
for await-loop, we get stuck waiting for a Readable stream which never ends.Is this expected behavior when piping multiple Readable streams into one Writable stream? Should one check
writable.writableNeedDrainbefore piping a Readable stream?submit a pull request.