public void Ad_Index_Contains_All_Products() { // Arrange - create the mock repository Mock <IAdvertisementRepository> mock = new Mock <IAdvertisementRepository>(); mock.Setup(m => m.Advertisements).Returns((new Advertisement[] { new Advertisement { AdvertisementID = 1, CompanyName = "A1" }, new Advertisement { AdvertisementID = 2, CompanyName = "A2" }, new Advertisement { AdvertisementID = 3, CompanyName = "A3" } }).AsQueryable <Advertisement>()); // Arrange - create a controller AdminController target = new AdminController(null, mock.Object); // Action Advertisement[] result = GetViewModel <IEnumerable <Advertisement> >(target.AdIndex())?.ToArray(); // Assert Assert.Equal(3, result.Count()); Assert.Equal("A1", result[0].CompanyName); Assert.Equal("A2", result[1].CompanyName); Assert.Equal("A3", result[2].CompanyName); }