public async void AddingStringQuestion() { var questionnaire = _dbMock.Object.Questionnaires.First(q => q.Id == 1); var expectedQuestion = _dbMock.Object.Questions.OfType <StringQuestion>().First(); var question = await _questionnaireService.AddQuestion(questionnaire.Id, expectedQuestion); Assert.NotNull(_questionnaireService.GetQuestionFromQuestionnaire(questionnaire.Id, question.Id)); Assert.Equal(expectedQuestion.Contents, question.Contents); _dbMock.Verify(x => x.SaveChangesAsync(), Times.Once); }