public void BankAccount_Controller_Update_ShouldBeOk() { //Arrange var isUpdated = true; _mockBankAccountService.Setup(bas => bas.Update(_mockBankAccount.Object)).Returns(isUpdated); //Action IHttpActionResult callback = _bankAccountController.Update(_mockBankAccount.Object); //Assert var httpResponse = callback.Should().BeOfType <OkNegotiatedContentResult <bool> >().Subject; httpResponse.Content.Should().BeTrue(); _mockBankAccountService.Verify(bas => bas.Update(_mockBankAccount.Object), Times.Once); }