public async Task SetPassiveAsync_DestinationBecameUnhealthy_SetUnhealthyAndScheduleReactivation()
        {
            var destination = new DestinationState("destination0");

            destination.Health.Active  = DestinationHealth.Healthy;
            destination.Health.Passive = DestinationHealth.Healthy;
            var cluster = CreateCluster(passive: true, active: false, destination);

            using var timerFactory = new TestTimerFactory();
            var updater = new DestinationHealthUpdater(timerFactory, GetClusterUpdater(), new Mock <ILogger <DestinationHealthUpdater> >().Object);

            await updater.SetPassiveAsync(cluster, destination, DestinationHealth.Unhealthy, TimeSpan.FromSeconds(2));

            timerFactory.VerifyTimer(0, 2000);
            Assert.Empty(cluster.DestinationsState.AvailableDestinations);
            Assert.Equal(DestinationHealth.Healthy, destination.Health.Active);
            Assert.Equal(DestinationHealth.Unhealthy, destination.Health.Passive);

            timerFactory.FireAll();

            Assert.Equal(DestinationHealth.Healthy, destination.Health.Active);
            Assert.Equal(DestinationHealth.Unknown, destination.Health.Passive);
            Assert.Equal(1, cluster.DestinationsState.AvailableDestinations.Count);
            Assert.Same(destination, cluster.DestinationsState.AvailableDestinations[0]);
            timerFactory.AssertTimerDisposed(0);
        }
        public async Task SetPassiveAsync_HealthSateIsNotChanged_DoNothing(DestinationHealth health)
        {
            var destination = new DestinationState("destination0");

            destination.Health.Active  = DestinationHealth.Healthy;
            destination.Health.Passive = health;
            var cluster = CreateCluster(passive: true, active: false, destination);

            using var timerFactory = new TestTimerFactory();
            var updater = new DestinationHealthUpdater(timerFactory, GetClusterUpdater(), new Mock <ILogger <DestinationHealthUpdater> >().Object);

            await updater.SetPassiveAsync(cluster, destination, health, TimeSpan.FromSeconds(2));

            Assert.Equal(0, timerFactory.Count);
            Assert.Equal(DestinationHealth.Healthy, destination.Health.Active);
            Assert.Equal(health, destination.Health.Passive);
        }
        public async Task SetPassiveAsync_DestinationBecameHealthy_SetNewState()
        {
            var destination = new DestinationState("destination0");

            destination.Health.Active  = DestinationHealth.Healthy;
            destination.Health.Passive = DestinationHealth.Unhealthy;
            var cluster = CreateCluster(passive: true, active: false, destination);

            using var timerFactory = new TestTimerFactory();
            var updater = new DestinationHealthUpdater(timerFactory, GetClusterUpdater(), new Mock <ILogger <DestinationHealthUpdater> >().Object);

            await updater.SetPassiveAsync(cluster, destination, DestinationHealth.Healthy, TimeSpan.FromSeconds(2));

            Assert.Equal(0, timerFactory.Count);
            Assert.Equal(DestinationHealth.Healthy, destination.Health.Active);
            Assert.Equal(DestinationHealth.Healthy, destination.Health.Passive);
            Assert.Equal(1, cluster.DestinationsState.AvailableDestinations.Count);
            Assert.Same(destination, cluster.DestinationsState.AvailableDestinations[0]);
        }