[Test] Health-probe timeout test never verifies recordProbeTimeout was called (false positive)

[kianwoon]

Description

The test "calls recordProbeTimeout when probe times out" sets up a fetchMock that never resolves, then races mgr.tick() against a 100ms timeout. After the race, it calls mgr.stop() but never asserts that recordProbeTimeout was actually called.

Worse: PROBE_TIMEOUT_MS in the source is 5000ms, so the probe's internal timeout never fires in the 100ms race window. recordProbeTimeout is genuinely never called — the test is a false positive.

Location

• tests/health-probe.test.ts:40-63
• src/health-probe.ts:5 (PROBE_TIMEOUT_MS = 5000)

Suggested Fix

Either:

1. Reduce PROBE_TIMEOUT_MS via dependency injection for testing
2. Mock the internal timer
3. At minimum, add expect(recordProbeTimeout).toHaveBeenCalled() to expose the gap

Severity

Critical — false positive test gives false confidence in health probe timeout handling