public void Post_Called_ReturnsResultOfValidateCredentials(AuthenticationResult returned) { // Arrange var mockProvider = new Mock <IAuthenticationProvider>(); mockProvider.Setup(x => x.ValidateCredentials(It.IsAny <string>(), It.IsAny <string>())).Returns(returned); var sut = new AccountsLoginService(Context, mockProvider.Object); // Act var result = sut.Post(new LoginModel()); // Assert Assert.Equal(returned, result); }