public async Task AddAsync_AddsItemToDatabase() { var numberOfItemsInDatabase = await _context.Subjects.AsQueryable().CountAsync(); await _service.CreateEntityAsync(new SubjectDto { Id = "testSubject1", Name = "Test Subject", LecturerId = "1" }); _context.Subjects.AsQueryable().CountAsync().Result.Should().Be(numberOfItemsInDatabase + 1); _validator.VerifyAll(); }