public async void EnrollUserInCourseById_OkResult() { // Arrange int courseId = 1; int studentId = 1; var mockCourseRepo = new Mock <IRepositoryAsync <Course> >(); mockCourseRepo.Setup(repo => repo.FindAsync(courseId)).ReturnsAsync(new Course()); var controller = new CourseController(null, mockCourseRepo.Object); // Act var result = await controller.EnrollUserInCourseById(courseId, studentId); // Assert Assert.IsType <OkResult>(result); }