public void Test_UpdateStock(int id) { var fakeContext = new FakeContext("UpdateProduct_Helper"); fakeContext.FillWithAll(); using (var context = new MainContext(fakeContext.FakeOptions, fakeContext.FakeConfiguration().Object)) { var productRepository = new ProductRepository(context); var repository = new SaleRepository(context); var productService = new Mock <IProductService>(); productService.Setup(x => x.GetById(It.IsAny <int>())).Returns(productRepository.GetById(id)); productService.Setup(x => x.Update(It.IsAny <int>(), It.IsAny <Product>())) .Returns <int, Product>((productId, product) => "{ Message = Produto alterado com sucesso. }"); var update = new UpdateProduct(productService.Object); var oldSale = repository.GetById(id); var newSale = new Sale(); newSale.ProductId = id; newSale.Quantity = 15; update.UpdateStock(newSale, oldSale); Assert.Equal(115, productRepository.GetById(id).Quantity); } }