Todo App Step 3 (Modifying State)

main.dart

class TodoListState extends State<TodoList> {
  List<String> _todoItems = [];

  // This will be called each time the + button is pressed
  void _addTodoItem() {
    // Putting our code inside "setState" tells the app that our state has changed, and
    // it will automatically re-render the list
    setState(() {
      int index = _todoItems.length;
      _todoItems.add('Item ' + index.toString());
    });
  }

  // Build the whole list of todo items
  Widget _buildTodoList() {
    return new ListView.builder(
      itemBuilder: (context, index) {
        // itemBuilder will be automatically be called as many times as it takes for the
        // list to fill up its available space, which is most likely more than the
        // number of todo items we have. So, we need to check the index is OK.
        if(index < _todoItems.length) {
          return _buildTodoItem(_todoItems[index]);
        }
      },
    );
  }

  // Build a single todo item
  Widget _buildTodoItem(String todoText) {
    return new ListTile(
      title: new Text(todoText)
    );
  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text('Todo List')
      ),
      body: _buildTodoList(),
      floatingActionButton: new FloatingActionButton(
        onPressed: _addTodoItem,
        tooltip: 'Add task',
        child: new Icon(Icons.add)
      ),
    );
  }
}

At line 17 i get an error from vsc saying:
Error: A non-null value must be returned since the return type 'Widget' doesn't allow null.

• 'Widget' is from 'package:flutter/src/widgets/framework.dart'
  ('../../Documents/flutter/packages/flutter/lib/src/widgets/framework.dart').
  itemBuilder: (context, index) {

The body might complete normally, causing 'null' to be returned, but the return type is a potentially non-nullable type.
Try adding either a return or a throw statement at the end.
(dartbody_might_complete_normally)

At line 17 i get an error from vsc saying: Error: A non-null value must be returned since the return type 'Widget' doesn't allow null.

• 'Widget' is from 'package:flutter/src/widgets/framework.dart'
  ('../../Documents/flutter/packages/flutter/lib/src/widgets/framework.dart').
  itemBuilder: (context, index) {

The body might complete normally, causing 'null' to be returned, but the return type is a potentially non-nullable type. Try adding either a return or a throw statement at the end. (dartbody_might_complete_normally)

Did you manage to fix it?