grafana/pkg/services/alerting/ticker_test.go

122 lines
3.5 KiB
Go

package alerting
import (
"testing"
"time"
"github.com/benbjohnson/clock"
)
func inspectTick(tick time.Time, last time.Time, offset time.Duration, t *testing.T) {
if !tick.Equal(last.Add(time.Duration(1) * time.Second)) {
t.Fatalf("expected a tick 1 second more than prev, %s. got: %s", last, tick)
}
}
// returns the new last tick seen
func assertAdvanceUntil(ticker *Ticker, last, desiredLast time.Time, offset, wait time.Duration, t *testing.T) time.Time {
for {
select {
case tick := <-ticker.C:
inspectTick(tick, last, offset, t)
last = tick
case <-time.NewTimer(wait).C:
if last.Before(desiredLast) {
t.Fatalf("waited %s for ticker to advance to %s, but only went up to %s", wait, desiredLast, last)
}
if last.After(desiredLast) {
t.Fatalf("timer advanced too far. should only have gone up to %s, but it went up to %s", desiredLast, last)
}
return last
}
}
}
func assertNoAdvance(ticker *Ticker, desiredLast time.Time, wait time.Duration, t *testing.T) {
for {
select {
case tick := <-ticker.C:
t.Fatalf("timer should have stayed at %s, instead it advanced to %s", desiredLast, tick)
case <-time.NewTimer(wait).C:
return
}
}
}
func TestTickerRetro1Hour(t *testing.T) {
offset := time.Duration(10) * time.Second
last := time.Unix(0, 0)
mock := clock.NewMock()
mock.Add(time.Duration(1) * time.Hour)
desiredLast := mock.Now().Add(-offset)
ticker := NewTicker(last, offset, mock)
last = assertAdvanceUntil(ticker, last, desiredLast, offset, time.Duration(10)*time.Millisecond, t)
assertNoAdvance(ticker, last, time.Duration(500)*time.Millisecond, t)
}
func TestAdvanceWithUpdateOffset(t *testing.T) {
offset := time.Duration(10) * time.Second
last := time.Unix(0, 0)
mock := clock.NewMock()
mock.Add(time.Duration(1) * time.Hour)
desiredLast := mock.Now().Add(-offset)
ticker := NewTicker(last, offset, mock)
last = assertAdvanceUntil(ticker, last, desiredLast, offset, time.Duration(10)*time.Millisecond, t)
assertNoAdvance(ticker, last, time.Duration(500)*time.Millisecond, t)
// lowering offset should see a few more ticks
offset = time.Duration(5) * time.Second
ticker.updateOffset(offset)
desiredLast = mock.Now().Add(-offset)
last = assertAdvanceUntil(ticker, last, desiredLast, offset, time.Duration(9)*time.Millisecond, t)
assertNoAdvance(ticker, last, time.Duration(500)*time.Millisecond, t)
// advancing clock should see even more ticks
mock.Add(time.Duration(1) * time.Hour)
desiredLast = mock.Now().Add(-offset)
last = assertAdvanceUntil(ticker, last, desiredLast, offset, time.Duration(8)*time.Millisecond, t)
assertNoAdvance(ticker, last, time.Duration(500)*time.Millisecond, t)
}
func getCase(lastSeconds, offsetSeconds int) (time.Time, time.Duration) {
last := time.Unix(int64(lastSeconds), 0)
offset := time.Duration(offsetSeconds) * time.Second
return last, offset
}
func TestTickerNoAdvance(t *testing.T) {
// it's 00:01:00 now. what are some cases where we don't want the ticker to advance?
mock := clock.NewMock()
mock.Add(time.Duration(60) * time.Second)
type Case struct {
last int
offset int
}
// note that some cases add up to now, others go into the future
cases := []Case{
{50, 10},
{50, 30},
{59, 1},
{59, 10},
{59, 30},
{60, 1},
{60, 10},
{60, 30},
{90, 1},
{90, 10},
{90, 30},
}
for _, c := range cases {
last, offset := getCase(c.last, c.offset)
ticker := NewTicker(last, offset, mock)
assertNoAdvance(ticker, last, time.Duration(500)*time.Millisecond, t)
}
}