public async Task CreateAsync_Should_ReturnCorrectQuiz() { var options = new DbContextOptionsBuilder <DataContext>() .UseInMemoryDatabase(databaseName: Guid.NewGuid().ToString()) .Options; using (var context = new DataContext(options)) { const string userId = "test"; var service = new QuizService(context); context.Questions.Add(new Question() { Id = 1 }); context.Questions.Add(new Question() { Id = 2 }); context.Questions.Add(new Question() { Id = 3 }); context.Questions.Add(new Question() { Id = 4 }); context.Questions.Add(new Question() { Id = 5 }); context.SaveChanges(); var quizId = await service.CreateAsync(userId); quizId.Should().Be(1); var questionQuizzes = context.QuestionQuizzes.Where(x => x.QuizId == quizId).ToList(); questionQuizzes.Count.Should().Be(5); } }