public async Task GetManufacturersTest() { var manufacturers = new List <Manufacturer> { new Manufacturer() { Name = "Said", Address = "USA LA" }, new Manufacturer() { Name = "Said", Address = "USA LA" }, }; var fakeRepositoryMock = new Mock <IManufacturerRepository>(); fakeRepositoryMock.Setup(x => x.GetManufacturers()).ReturnsAsync(manufacturers); var manufacturerService = new ManufacturerService(fakeRepositoryMock.Object); var resultManufacturers = await manufacturerService.GetManufacturers(); Assert.Collection(resultManufacturers, manufacturer => { Assert.Equal("Said", manufacturer.Name); }, manufacturer => { Assert.Equal("USA LA", manufacturer.Address); }); }