public void ShouldReturnErrorsListAndResultsList() { var input = new List <Either <Error, string> > { new TestError("test error message1"), "valid value", "valid value2", new TestError("test error message2") }; var expectedErrors = new List <Error> { new TestError("test error message1"), new TestError("test error message2") }; var expectedValues = new List <string> { "valid value", "valid value2" }; var expected = (expectedErrors, expectedValues); var result = HomeModel.AggregateEithers(input); Assert.AreEqual(expected, result); }