public async Task GetAllByListIdAsync_Should_Return_All_Todo_Items_From_A_List() { // Arrange var todoItems = Builder <TodoItem> .CreateListOfSize(10).Build().ToList(); TodoItemRepository.GetAllAsync(Arg.Any <Expression <Func <TodoItem, bool> > >()).Returns(todoItems); // Act var result = await _sut.GetAllByListIdAsync(Guid.NewGuid()); // Assert result.Should().HaveCount(10); await TodoItemRepository.Received().GetAllAsync(Arg.Any <Expression <Func <TodoItem, bool> > >()); }