public void Corpus_FirstLetter_CorrectLetterGivenWeight(double weight, string expected) { // Arrange var rawData = new string[] { "dummy", "e,x [0.5%],a [0.4%]", " ,p [5.0%],a [7.5%],j [9.0%]" }; var corpus = new Corpus { RawData = rawData }; corpus.ProcessLinesToLetters(); // Act var result = corpus.GetFirstLetter(weight).Letter; // Assert Assert.That(result, Is.EqualTo(expected)); }