package statistics import ( "math" "testing" "time" "go.uber.org/atomic" ) func TestBackoff(t *testing.T) { stats := Statistics{ FailuresUntilBlacklist: 5, } server := ServerStatistics{ statistics: &stats, serverName: "test.com", } // Start by checking that counting successes works. server.Success() if successes := server.SuccessCount(); successes != 1 { t.Fatalf("Expected success count 1, got %d", successes) } // Register a failure. server.Failure() t.Logf("Backoff counter: %d", server.backoffCount.Load()) backingOff := atomic.Bool{} // Now we're going to simulate backing off a few times to see // what happens. for i := uint32(1); i <= 10; i++ { // Interrupt the backoff - it doesn't really matter if it // completes but we will find out how long the backoff should // have been. interrupt := make(chan bool, 1) close(interrupt) // Get the duration. duration, blacklist := server.BackoffIfRequired(backingOff, interrupt) // Check if we should be blacklisted by now. if i > stats.FailuresUntilBlacklist { if !blacklist { t.Fatalf("Backoff %d should have resulted in blacklist but didn't", i) } else { t.Logf("Backoff %d is blacklisted as expected", i) continue } } // Check if the duration is what we expect. t.Logf("Backoff %d is for %s", i, duration) if wanted := time.Second * time.Duration(math.Exp2(float64(i))); !blacklist && duration != wanted { t.Fatalf("Backoff %d should have been %s but was %s", i, wanted, duration) } } }