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Stream.pipeline() does not call the callback on completion #34059
Description
- Version: 12.18.0 and 14.4.0
- Platform: Ubuntu 20.04 LTS
- Subsystem:
I use the following code to test the callback of the pipeline() function under node 12.18.0 and node 14.4.0:
'use strict';
import {pipeline, Readable} from 'stream';
import {createWriteStream} from 'fs';
pipeline(
Readable.from(['a', 'b', 'c', '\r\n']),
process.stdout,
(err) => {
console.log('finish callback stdout');
}
);
pipeline(
Readable.from(['a', 'b', 'c', '\r\n']),
createWriteStream('outfile.txt'),
(err) => {
console.log('finish callback file write stream');
}
);
Under Node 12.18.0, the callback on the second pipeline() is called on completion, but the callback on the first is not.
Same problem on Node 14.4.0.
Activity
jasnell commentedon Jun 26, 2020
@nodejs/streams
ronag commentedon Jun 26, 2020
process.stdout+end()inpipe@vweevers. Maybe related #32373mcollina commentedon Jun 26, 2020
I thought #32373 was supposed to fix this.
ronag commentedon Jun 26, 2020
This works as intended. The callback is called in both cases. At least on Node 14.
The
stdoutexample doesn't print anything because pipeline closesstdoutbefore the callback is invoked, hence theconsole.log(which usesstdout) doesn't do anything. Changing toconsole.errorwill properly print as expected.mcollina commentedon Jun 27, 2020
I think we can close.
matdodgson commentedon Jun 29, 2020
Apologies - should have used better testing code! The problem is fixed in v14 (I assume #32373) so just waiting on the back port to v12.