public async Task GetProductsReturnsProductUsingInValidId() { var options = new DbContextOptionsBuilder <ProductsDbContext>() .UseInMemoryDatabase(nameof(GetProductsReturnsProductUsingInValidId)) .Options; var dbContext = new ProductsDbContext(options); CreateProducts(dbContext); var productprofile = new ProductProfile(); var configuration = new MapperConfiguration(cfg => cfg.AddProfile(productprofile)); var mapper = new Mapper(configuration); var productsProvider = new ProductsProvider(dbContext, null, mapper); var product = await productsProvider.GetProductByIdAsync(-1); Assert.False(product.IsSuccess); Assert.Null(product.Product); Assert.NotNull(product.ErrorMessage); }