public void GetChaptersOfCourseAsyncShouldReturnEmptyListWhenNotCurrentPeriodIsFound() { //Arrange var courseId = _random.NextPositive(); _periodRepositoryMock.Setup(repo => repo.GetCurrentPeriodAsync()).Throws <DataNotFoundException>(); //Act var result = _service.GetChaptersOfCourseAsync(courseId).Result; //Assert _periodRepositoryMock.Verify(repo => repo.GetCurrentPeriodAsync(), Times.Once); _chapterRepositoryMock.Verify(repo => repo.GetByCourseIdAsync(It.IsAny <int>(), It.IsAny <int>()), Times.Never); Assert.That(result, Is.Empty); }