test: fix race condition in watch mode tests #61615
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Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #61615 +/- ##
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The watch mode tests using runInBackground() had a race condition where stdout "Failed running" message could arrive before stderr was fully collected, causing assertions on stderr content to fail with empty strings. Fix by waiting for stderr 'data' event if stderr is empty when "Failed running" is detected. This is an event-driven approach rather than timing-based. Refs: nodejs/reliability#1450
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Failed to start CI⚠ Commits were pushed since the last approving review: ⚠ - test: fix race condition in watch mode tests ✘ Refusing to run CI on potentially unsafe PRhttps://github.com/nodejs/node/actions/runs/21602719238 |
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Summary
Fixes race condition in watch mode tests that caused intermittent failures.
Problem
The watch mode tests using
runInBackground()had a race condition where the stdout "Failed running" message could arrive before stderr was fully collected, causing assertions on stderr content to fail with empty strings.Solution
When "Failed running" is detected in stdout and stderr is empty, wait for the stderr 'data' event before resolving the promise. This is an event-driven approach rather than timing-based.
Verification
test-watch-mode-restart-esm-loading-error.mjs: 200 runs, 0 failurestest-watch-mode.mjs: 50 runs, 0 failuresRefs: nodejs/reliability#1450