dotnet
Fix race condition in UnreliableL2Tests.WriteFailureInvisible
The test was intermittently failing in CI because L2 write failures are logged asynchronously after the background write task completes, but the test used a fixed 150ms delay that didn't reliably wait for logging to finish.
Changes
- LogCollector: Added
WaitForLogsAsyncthat polls for expected log entries with timeout instead of guessing timing - UnreliableL2Tests: Replaced fixed delay with
WaitForLogsAsync(errorIds, TimeSpan.FromSeconds(5))
The polling logic matches AssertErrors exactly (count and order must match), ensuring test assertions see the same log state that will be verified.
// Before: unreliable fixed delay
await l2.LastWrite;
await Task.Delay(150); // thread jitter caused failures
log.AssertErrors(errorIds);
// After: poll until logs appear or timeout
await l2.LastWrite;
await log.WaitForLogsAsync(errorIds, TimeSpan.FromSeconds(5));
log.AssertErrors(errorIds);
Original prompt
This test failed in CI. Please either investigate the flakiness and fix it, or disable the test if it's inherently flaky:
Microsoft.Extensions.Caching.Hybrid.Tests.UnreliableL2Tests.WriteFailureInvisible(writeBreak: AsynchronousYield, errorIds: [7])
Result Details Failed 39m ago on 642af2e5c000000 Duration0:00:00.673 Ownernot available Date started11/21/2025, 9:29:23 AM Date completed11/21/2025, 9:29:24 AM Failing since37m ago Failing since build20251121.17
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Error message Assert.Equal() Failure: Strings differ ↓ (pos 0) Expected: "7" Actual: ""
Stack trace at Microsoft.Extensions.Caching.Hybrid.Tests.LogCollector.AssertErrors(Int32[] errorIds) in /mnt/vss/_work/1/s/test/Libraries/Microsoft.Extensions.Caching.Hybrid.Tests/LogCollector.cs:line 60 at Microsoft.Extensions.Caching.Hybrid.Tests.UnreliableL2Tests.WriteFailureInvisible(BreakType writeBreak, Int32[] errorIds) in /mnt/vss/_work/1/s/test/Libraries/Microsoft.Extensions.Caching.Hybrid.Tests/UnreliableL2Tests.cs:line 49 --- End of stack trace from previous location ---
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