public async Task CalcualteOrderTax_Expect_SuccessAsync() { //arrange _mockApiClient.Setup(x => x.ApiCall <OrderTaxResponse>(HttpMethod.Post, It.IsAny <string>(), It.IsAny <string>(), It.IsAny <string>(), It.IsAny <object>())).Returns(Task.FromResult(new OrderTaxResponse() { Tax = new Domain.Entities.Tax() { Rate = 10, Amount_to_collect = 10, Taxable_amount = 50, Order_total_amount = 1000, Shipping = 20 } })).Verifiable(); //act var actual = await _repository.TaxForOrder(new Domain.OrderTaxApiRequest()); //assert Assert.NotNull(actual); _mockApiClient.Verify(); Assert.Equal(10, actual.Tax.Rate); Assert.Equal(20, actual.Tax.Shipping); }