[andrewfader]

Fixes #22366

Cancelling a ReadableStreamDefaultReader whose stream has errored, e.g. after a network error, returns a promise rejected with that error, which was never handled. This affects the fetch, worker, and Node.js stream readers.

The new tests in fetch_stream_spec.js and node_stream_spec.js fail on master with an unhandled rejection, and pass with this patch. They don't need any new test files.

Regarding the review of #22306: the same fix is applied to node_stream.js, as well as to worker_stream.js, so the implementations stay in sync.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.58%. Comparing base (22f5df1) to head (743422f).
⚠️ Report is 14 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #22371      +/-   ##
==========================================
- Coverage   90.58%   90.58%   -0.01%     
==========================================
  Files         278      278              
  Lines       68568    68584      +16     
==========================================
+ Hits        62115    62125      +10     
- Misses       6453     6459       +6     

Flag	Coverage Δ
browsertest	66.27% <66.66%> (-0.02%)	⬇️
fonttest	8.99% <ø> (ø)
integrationtest	69.60% <33.33%> (+0.05%)	⬆️
unittest	61.27% <66.66%> (+<0.01%)	⬆️
unittestcli	59.01% <100.00%> (+<0.01%)	⬆️

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[github-actions]

Viewer preview

🗑️ Viewer previews removed.

[codspeed]

Merging this PR will improve performance by 24.42%

⚡ 1 improved benchmark
✅ 87 untouched benchmarks
⏩ 174 skipped benchmarks¹

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
⚡	getUnicodeRangeFor (bug1473809.pdf)	33.4 ms	26.9 ms	+24.42%

Tip

Curious why performance improved? Comment @codspeedbot explain why performance improved on this PR, or directly use the CodSpeed MCP with your agent.

---

_{Comparing andrewfader:stream-reader-cancel-errored (743422f) with master (ab3819f)}

Footnotes

1. 174 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[Snuffleupagus]

The commits must be squashed.

[Snuffleupagus]

Hmm, why does the commit now list me as co-author?

[andrewfader]

Whoops sorry it's because I squashed the auto-suggested review commits. I'll --reset-author.

[andrewfader]

Sorry @Snuffleupagus, force-pushed a clean commit with just me as author.

[github-actions]

Reference tests

Results for 743422f (run, references from mozilla/pdf.js.refs@d16403bcaa).

Platform	Status	Tests	Total runtime	Errors	Different	FBF	No reference	Report
	⚠️	1413	12m 21s	0	10	0	0	view differences
	⚠️	1413	14m 2s	0	10	0	0	view differences

The report is kept for 30 days and replaced by the next run.