Right AND Wrong?

JavaScript
4

Remove the updater function and just return an object. You are not doing anything with the current state anyway, so you do not need the updater function.

this.setState({input: event.target.value});

If you did want to use event.target.value in the updater function I believe you would have to capture it in the handler and pass that to the updater.

handleChange(event) {
  const targetValue = event.target.value;
  this.setState((state, props) => {
    return { input: targetValue }
  })
};

It has to do with how setState and events works.