Function TestScheduler

internal/scheduler/scheduler_test.go:20–81

(t *testing.T)

var baseTime = time.Date(2020, 1, 1, 0, 0, 0, 0, time.UTC)

func TestScheduler(t *testing.T) {
	ch := make(chan string, 1000)

	// times of upcoming events
	it1 := scheduler.Item{"it1", baseTime.Add(100 * time.Millisecond), reportTriggered(t, ch, "it1")}
	it2a := scheduler.Item{"it2", baseTime.Add(200 * time.Millisecond), reportTriggered(t, ch, "it2")}
	it2b := scheduler.Item{"it2", baseTime.Add(200 * time.Millisecond), reportTriggered(t, ch, "it2")}
	it3a := scheduler.Item{"it3", baseTime.Add(300 * time.Millisecond), reportTriggered(t, ch, "it3")}
	it3b := scheduler.Item{"it3", baseTime.Add(300 * time.Millisecond), reportTriggered(t, ch, "it3")}
	it4 := scheduler.Item{"it4", baseTime.Add(30 * time.Hour), reportTriggered(t, ch, "it4")}

	items := []scheduler.Item{it1, it2a, it2b, it3a, it3b, it4}

	// verify that the item order does not matter by shuffling the items.
	rand.Shuffle(len(items), func(i, j int) { items[i], items[j] = items[j], items[i] })

	ctx := testlogging.Context(t)

	ft := faketime.NewClockTimeWithOffset(baseTime.Sub(clock.Now()))

	refresh := make(chan string)
	s := scheduler.Start(ctx, func(ctx context.Context, now time.Time) []scheduler.Item {
		var result []scheduler.Item

		for _, it := range items {
			if it.NextTime.After(now) {
				result = append(result, it)
			}
		}

		return result
	}, scheduler.Options{
		TimeNow:        ft.NowFunc(),
		Debug:          true,
		RefreshChannel: refresh,
	})

	defer s.Stop()

	// ensure that the first few items are triggered in order.
	require.Equal(t, "it1", <-ch)
	require.Equal(t, "it2", <-ch)
	require.Equal(t, "it2", <-ch)
	require.Equal(t, "it3", <-ch)
	require.Equal(t, "it3", <-ch)

	// it4 is far into the future, make sure nothing is triggered immediately
	select {
	case v := <-ch:
		t.Fatalf("unexpected item: %v", v)

	case <-time.After(1 * time.Second):
	}

	// now change the set of items returned by adding it5 which comes before it4
	it5 := scheduler.Item{"it5", ft.NowFunc()().Add(time.Second), reportTriggered(t, ch, "it5")}
	items = []scheduler.Item{it1, it2a, it2b, it3a, it3b, it4, it5}