public void Should_Start_Services()
{
//Arrange
var service = new Mock <IService>();
var repository = Mock.Of <IServiceRepository>(_ => _.Get() == new[] { service.Object });
var subject = new SomeServiceHost(repository);
ServiceStatus before = subject.Status;
ServiceStatus during = default(ServiceStatus);
service.Setup(_ => _.Start()).Callback(() => during = subject.Status);
//Act
subject.Start();
ServiceStatus after = subject.Status;
//Assert
before.Should().Be(ServiceStatus.Stopped);
during.Should().Be(ServiceStatus.Starting);
after.Should().Be(ServiceStatus.Running);
service.Verify(_ => _.Start()); //invoked at least once;
}