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stream: Readable iterator unhandled error when piping #28194
Description
- Version: 12.4
- Platform: Ubuntu 18.04
When using asyncIterator on a piped stream, the error is not handled correctly.
const fs = require('fs');
const { PassThrough } = require('stream');
async function print() {
const read = fs.createReadStream('file');
const iterator = read.pipe(new PassThrough())
for await (const k of iterator) {
console.log(k);
}
}
print()
.then(() => console.log('done')) // never called
.catch(console.log); // never calledIn the above example, the .catch is not catching the error, and the script crashes.
I know, that I should catch the error of each stream, but if I do:
read.on('error', console.log);The print function never resolves nor rejects. The only solution I've found is to emit the error to the piped stream.
async function print() {
const read = fs.createReadStream('file');
const stream = new PassThrough();
read.on('error', (err) => stream.emit('error', err));
const iterator = read.pipe(stream);
for await (const k of iterator) {
console.log(k);
}
}When you have multiple pipes, this can get very ugly. I don't know if this is the intended behaviour, but makes it hard & ugly to work with async iterators.
Activity
Fishrock123 commentedon Jun 13, 2019
I don't know for sure, but does
stream.pipeline()solve this?marcosc90 commentedon Jun 13, 2019
No, it doesn't unfortunately, because the error is passed to the
.pipelinecallback, so thefor awaitdoes not throw, and theprintfunction resolves without iterating anything, instead of throwing.stream: propagate errors from src streams in async iterator
stream: make all streams error in a pipeline
stream: make all streams error in a pipeline
stream: make all streams error in a pipeline
stream: make all streams error in a pipeline