public async Task Can_enroll_and_drop_a_student() { // Arrange var student = await CreateAndSaveTestStudent(); var course = await CreateAndSaveTestCourse(); var repository = new CourseRepository(_db); // Act await repository.AddStudent(course.Id, student.Id); // Assert var actualCourse = await repository.GetOne(course.Id); Assert.Contains(actualCourse.Enrollments, e => e.StudentId == student.Id); // Act await repository.RemoveStudentFromCourse(course.Id, student.Id); // Assert actualCourse = await repository.GetOne(course.Id); Assert.DoesNotContain(actualCourse.Enrollments, e => e.StudentId == student.Id); }