FakeClock does not behave like RealClock on Go >= 1.23

[TheSven73]

Ever since Go 1.23, the fake and real clocks behave differently:

func Test_RealTimer(t *testing.T) {
	c := clockwork.NewRealClock()
	test_drainTimer(t, c, func() {
		c.Sleep(time.Second)
	})
}

func Test_FakeTimer(t *testing.T) {
	c := clockwork.NewFakeClock()
	test_drainTimer(t, c, func() {
		c.Advance(time.Second)
	})
}

func test_drainTimer(t *testing.T, c clockwork.Clock, advanceTime func()) {
	timer := c.NewTimer(time.Second)
	advanceTime()
	timer.Reset(time.Second)
	if len(timer.Chan()) > 0 {
		t.Fatal("timer didn't reset, but fired immediately")
	}
}

On Go 1.22 Fake and Real give an identical and correct result (the timer should be drained)

main_test.go:111: timer didn't reset, but fired immediately
main_test.go:111: timer didn't reset, but fired immediately

However on Go 1.23, Fake and Real behave differently:

main_test.go:111: timer didn't reset, but fired immediately

See also #84

[StevenACoffman]

@DPJacques Have you considered a way to correct this behavior on newer Go versions?

[DPJacques]

Unfortunately, some non-open-source issues have had me considerably distracted. I need to come back into context on this.

In the test code, what would advanceTime() do for a real clock? I assume nothing and reset is called immediately?

The change from Go 1.23 was difficult to navigate and reason about. I have not had much time to come back to this.