what's the use of getDerivedStateFromProps (or how do you fire it?)

I have the following 'List' component where I'm trying to update this.state from props. I can't seem to get getDrivedStateFromProps to work correctly with componentDidUpdate. There's a problem with the logic but it doesn't seem that gDSFC ever fires as I get the same response whether it's commented out or not.

<!DOCTYPE html>
<html>
   <head>
      <meta charset="UTF-8" />
      <title>list</title>
      <script src="react/react.js"></script>
      <script src="react/react-dom.js"></script>
      <script src="https://unpkg.com/[email protected]/babel.min.js"></script>
   </head>
   <body>
      <div id='container'>
      </div>
   </body>
</html>


<script type = 'text/jsx'>

class FilteredList extends React.Component{
   constructor(props){
      super(props);
      this.state={list:this.props.list};
   }

   filter(input){
      var newList = this.state.list.filter(function(item){
         return (item.search(input.target.value)!=-1);
      });

      this.setState({list:newList});

   }

   render(){

      return(
         <div>
            <input type='text' placeholder='Filter' onChange={this.filter.bind(this)} />
            <List items={this.state.list} />
         </div>
      );
   }
}

class List extends React.Component{
   constructor(props){
      super(props);
      this.state={items:this.props.items};
   }

    static getDerivedStateFromProps(nextProps, prevState) {
      console.log('hello1');
    if (nextProps.items !== prevState.items) {
      return {
        items: nextProps.items,
      };
    }
    // Return null if the state hasn't changed
    return null;
  }

   componentDidUpdate(nextProps,prevState){
      console.log('hello2');
      if(nextProps.items !== prevState.items)
      this.setState({items:nextProps.items});
   }



   render(){



      return(
         <ul>
            {this.state.items.map(function(item){
               return(<li key={item}>{item}</li>);
            })}
         </ul>

      );
   }
}

   ReactDOM.render(
      <div><FilteredList list={['anteater','bear','cat','dog','elephant','fox']} /></div>,
      document.getElementById('container')
);
</script>

Solution

Upgrade to v5.2.1 or higher and this open issue should be fixed yarn upgrade -L react-helmet

I think you need 16.3.1 or later, possibly 16.3.3