Backpressure implementation seems incorrect

[thynson]

https://github.com/tim-smart/multipasta/blob/bf352fbf3a9fcd07e733068430fcfc00dedbfd15/src/node.ts#L61

According to the document, when Readable.push returns false, no more data should be pushed to it anymore until _read being called.

This requires changing the onFile callback, and, ultimately the Parser itself needs to be able to pause/resume.

Also, src/node.ts and src/web.ts should be exported through package.json#exports since you set type to be "module".

[tim-smart]

When _canWrite is false, writes are suspended until _read is called on the current file stream: https://github.com/tim-smart/multipasta/blob/main/src/node.ts#L123

[tim-smart]

Regarding exports, they are adding during the build. You can see the final package.json on npm here: https://www.npmjs.com/package/multipasta?activeTab=code

[thynson]

When _canWrite is false, writes are suspended until _read is called on the current file stream:

But we need to pause the Parser, otherwise onFile or onField would be still called even if _canWrite is false.

[thynson]

While the ability to pause/resume is not implemented for Parser yet.

[tim-smart]

The parser is fully synchronous, so to pause it you just need to stop writing to it :)

[thynson]

But I'm concerning that even if the write side were paused, the last chunk written to the parser could result in too many events emitted.

And the return value of these this.push is unchecked: https://github.com/tim-smart/multipasta/blob/bf352fbf3a9fcd07e733068430fcfc00dedbfd15/src/node.ts#L53 and https://github.com/tim-smart/multipasta/blob/bf352fbf3a9fcd07e733068430fcfc00dedbfd15/src/node.ts#L58

[tim-smart]

Right, I'm not too worried about that. Node has its own buffer for this - the main thing is that you pause the upstream to propagate the backpressure.