EBADF with streams and pipeline

[rijnhard]

See #260

to address the comments: no you cannot catch the error using .catch or try/catch
that was the point of this answer #260 (comment)

Basically (I realise there is a language barrier) you cannot catch the error, at least nothing I did could.

[rijnhard]

I also don't see how detachDescriptor will solve this problem @benjamingr.

The problem is that I get an UNCATCHABLE EBADF error if the descriptor is already closed and I close it.

Especially since it's not possible to tell if the descriptor is already closed (at least I could not find a way).

[silkentrance]

detachDescriptor will cause tmp to not try to close the already closed file.

[rijnhard]

But it will also mean that I have to close it manually, correct?

that may be a valid workaround to my case.
But the issue here is that the error thrown is not catchable at all, which should be rectified

[benjamingr]

The problem is that I get an UNCATCHABLE EBADF error if the descriptor is already closed and I close it.

Create a (short!) repro of the issue?

[benjamingr]

There is no such thing as an "uncatchable EBADF" in Node.js as far as I know - the only way that could happen is if someone (either node-tmp or your code) is not propagating the error.

[rijnhard]

thats exactly it, I think `node-tmp` is not propagating it correctly, I'll make a reproducible example

…

On Sun, 17 Jan 2021 at 12:29, Benjamin Gruenbaum ***@***.***> wrote: There is no such thing as an "uncatchable EBADF" in Node.js as far as I know - the only way that could happen is if someone (either node-tmp or your code) is not propagating the error. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#267 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABAXP2FPO5DIT4UGUO63WI3S2K3ZNANCNFSM4WCMQP4A> .

[rijnhard]

So firstly, I apologise... it turns out the problem was caused by the magic handling of file descriptors with streams.

const destination = await tmp.fileSync();
const stream = fs.createWriteStream(destination.path, { fd:destination.fd });

const abort = () => {
    destination.cleanup();
}

// later on in another function
await ppipeline( // just a promisified pipeline function
    source,
    async function* (source) {
        yield source.read(); // just a random transform function that can break at any time.
    },
    destination.stream
)

So let me just put this down if anyone else has an issue with node-tmp and streams.

1. FileStream behaviour: if you use the util.pipeline function with a file stream, it will automatically close that stream, on completion or failure.
2. ppipeline actually throws the error, but because of how node handles this it has no stack trace.

I only figured this out when trying to reproduce this because the abort function can actually be triggered at any point by a number of other functions in my code and the pipeline is also actually engaged somewhere else.