test: stabilize flaky fs.watch and worker-scaler tests - #4806
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- Skip the two FileWatcher tests that exercise fs.watch on Windows + Node 24 to avoid the libuv assertion in src/win/fs-event.c tracked upstream as nodejs/node#63638. - Replace the single short CPU burst + fixed sleep in the worker-scaler cooldown test with sustained load and polling for the expected worker count, so the scale-up is observed deterministically. Assisted-by: claude-code:claude-opus-4-7 Signed-off-by: Matteo Collina <[email protected]>
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ivan-tymoshenko
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ShogunPanda
May 29, 2026 10:35
ivan-tymoshenko
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May 29, 2026
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Summary
FileWatchertests that exercisefs.watchon Windows + Node 24. They abort the process withAssertion failed: !_wcsnicmp(filename, dir, dirlen), file src\win\fs-event.c, line 72— a libuv regression tracked upstream at nodejs/node#63638. The skip is gated onprocess.platform === 'win32' && Node ≥ 24so the tests keep running everywhere they're known to be safe.worker-scaler"should not scale during cooldown" test to drive sustained CPU load in the background and poll for the expected worker count instead of issuing a single short burst and sleeping a fixed 10s. The original shape was timing-fragile: the worker was blocked during the burst, the scaler's health check often couldn't observe the high ELU before the load ended, and the assertion landed at 1 worker instead of 2. With polling and continuous load the scale-up is observed deterministically — typical run time dropped to ~2s, with a 30s upper bound.Test plan
packages/foundation—node --test test/file-system.test.js(22/22 pass locally on Linux + Node 24)packages/runtime—node --test --test-concurrency=1 test/worker-scaler-1.test.js(15/15 pass locally; the previously flaky cooldown test passes in bothdefaultandworker-scalerconfigurations)foundation - windows-2025 - 24andruntime - * - mainjobs are green🤖 Generated with Claude Code