mock time with "go.chromium.org/luci/common/clock" package

new_solution.go

import (
  "go.chromium.org/luci/common/clock"
)

type ClockTime struct {
	clock.Clock
}

var _ gocron.TimeWrapper = ClockTime{}

func (ct ClockTime) Now(loc *time.Location) time.Time {
	return ct.Clock.Now().In(loc)
}

func (ClockTime) Unix(sec, nsec int64) time.Time {
	return time.Unix(sec, nsec)
}

func (ct ClockTime) Sleep(d time.Duration) {
	ct.Clock.Sleep(context.Background(), d)
}

func TestSchedulerMock(t *testing.T) {
	// A clock that runs 60x faster than real clock.
	clock := testclock.NewFastClock(time.Now(), 60)
	defer clock.Close()

	fmt.Printf("clock set at %s\n", clock.Now().UTC().Format(time.RFC3339))

	s := gocron.NewScheduler(time.UTC)
	s.CustomTime(ClockTime{clock})

	var count int
	_, err := s.Every(2).Second().Do(func() {
		fmt.Printf("Triggered: %v (real time=%v)\n", clock.Now().UTC().Format(time.RFC3339), time.Now().UTC().Format(time.RFC3339))
		count++
	})
	require.NoError(t, err)
	s.StartAsync()

	start := time.Now()
	for {
		if count == 10 {
			break
		}
	}
	fmt.Printf("done in %v\n", time.Since(start))
}