public void AddVendor() { var mocks = Mock.Mocks.New(); var vendors = new List <Vendor>(); var servicesMock = mocks .NewDbSet <Data.Entities.Service>() .IsEnumerable(new [] { new Data.Entities.Service { Key = "TestKey", Vendors = vendors } }); var dbContextMock = mocks .NewDbContext <MirrorDbContext>() .WithDbSet(context => context.Services, servicesMock.Object) .SavedChanges(); var serviceManager = new ServiceManager(dbContextMock.Object); serviceManager.AddVendor("TestKey", new Vendor { Url = "TestUrl" }); Assert.AreEqual(1, vendors.Count); mocks.VerifyAll(); }