public async Task UpdateAsync_Should_Throw_Exception_If_Todo_List_Does_Not_Belong_To_HimAsync()
    {
        //Arrange
        var updateTodoListModel = Builder <UpdateTodoListModel> .CreateNew().Build();

        var todoList = Builder <TodoList> .CreateNew().Build();

        TodoListRepository.GetFirstAsync(Arg.Any <Expression <Func <TodoList, bool> > >()).Returns(todoList);

        //Act
        Func <Task> callUpdateAsync = async() => await _sut.UpdateAsync(Guid.NewGuid(), updateTodoListModel);

        //Assert
        await callUpdateAsync.Should().ThrowAsync <BadRequestException>()
        .WithMessage("The selected list does not belong to you");

        await TodoListRepository.Received().GetFirstAsync(Arg.Any <Expression <Func <TodoList, bool> > >());

        ClaimService.Received().GetUserId();
    }
    public async Task CreateAsync_Should_Add_New_Entity_To_Database()
    {
        // Arrange
        var createTodoItemModel = Builder <CreateTodoItemModel> .CreateNew().Build();

        var todoList = Builder <TodoList> .CreateNew().Build();

        var todoItem = Builder <TodoItem> .CreateNew().With(ti => ti.Id = Guid.NewGuid()).Build();

        TodoListRepository.GetFirstAsync(Arg.Any <Expression <Func <TodoList, bool> > >()).Returns(todoList);
        TodoItemRepository.AddAsync(Arg.Any <TodoItem>()).Returns(todoItem);

        // Act
        var result = await _sut.CreateAsync(createTodoItemModel);

        // Assert
        result.Id.Should().Be(todoItem.Id);
        await TodoListRepository.Received().GetFirstAsync(Arg.Any <Expression <Func <TodoList, bool> > >());

        await TodoItemRepository.Received().AddAsync(Arg.Any <TodoItem>());
    }
    public async Task DeleteAsync_Should_Delete_Entity_From_Database()
    {
        //Arrange
        var todoListId = Guid.NewGuid();
        var todoList   = Builder <TodoList> .CreateNew()
                         .With(tl => tl.CreatedBy = new Guid().ToString())
                         .With(tl => tl.Id        = todoListId)
                         .Build();

        TodoListRepository.GetFirstAsync(Arg.Any <Expression <Func <TodoList, bool> > >()).Returns(todoList);
        TodoListRepository.DeleteAsync(Arg.Any <TodoList>()).Returns(todoList);

        //Act
        var result = await _sut.DeleteAsync(Guid.NewGuid());

        //Assert
        result.Id.Should().Be(todoListId);
        await TodoListRepository.Received().GetFirstAsync(Arg.Any <Expression <Func <TodoList, bool> > >());

        await TodoListRepository.Received().DeleteAsync(Arg.Any <TodoList>());
    }
    public async Task UpdateAsync_Should_Update_Existing_Entity_From_DatabaseAsync()
    {
        //Arrange
        var updateTodoListModel = Builder <UpdateTodoListModel> .CreateNew().Build();

        var todoListId = Guid.NewGuid();
        var todoList   = Builder <TodoList> .CreateNew()
                         .With(tl => tl.CreatedBy = new Guid().ToString())
                         .With(tl => tl.Id        = todoListId)
                         .Build();

        TodoListRepository.GetFirstAsync(Arg.Any <Expression <Func <TodoList, bool> > >()).Returns(todoList);
        TodoListRepository.UpdateAsync(Arg.Any <TodoList>()).Returns(todoList);

        //Act
        var result = await _sut.UpdateAsync(todoListId, updateTodoListModel);

        //Assert
        result.Id.Should().Be(todoListId);
        await TodoListRepository.Received().GetFirstAsync(Arg.Any <Expression <Func <TodoList, bool> > >());

        ClaimService.Received().GetUserId();
        await TodoListRepository.Received().UpdateAsync(Arg.Any <TodoList>());
    }