Error: file data stream has unexpected number of bytes

Hi!

For some reason, I occasionally get the following error when trying to create a zip file. I’d be really grateful if you were able to provide any insight.

Uncaught Exception:
Error: file data stream has unexpected number of bytes
    at ByteCounter.<anonymous> (/Applications/Castbridge.app/Contents/Resources/app.asar/node_modules/yazl/index.js:144:99)
    at emitNone (events.js:91:20)
    at ByteCounter.emit (events.js:185:7)
    at endReadableNT (_stream_readable.js:974:12)
    at _combinedTickCallback (internal/process/next_tick.js:74:11)
    at process._tickCallback (internal/process/next_tick.js:98:9)

Thanks!

[thejoshwolfe]

My best guess is that the file you’re trying to add to the archive is being modified while yazl is attempting to read it. The specific error means that the fs.ReadStream that’s reading the file produced a different number of bytes than the fs.stat() call predicted it would. (Either that or there’s a serious bug in yazl.)

If I had to guess, I would say that you’re writing files to the file system from some source and then immediately zipping them up into an archive. There’s a really easy mistake to make with Node.js programming where you don’t wait for a WriteStream to fully finish writing its data before you try to read the file. For example, if you wait for a stream earlier in the pipeline to end instead, then you’ll get intermittent failures like the one you’re getting.

That’s all a really specific guess though. Your situation may be different. Can you verify that the files you’re sending to addFile() are not changing while yazl is reading them?

[thejoshwolfe]

that’s a relief to hear.

(no need to delete any comments.)