blah.jsx

export default class MerchCoReports extends React.Component {
  constructor(serverProps, context) {
    super(serverProps, context);
    this.state = {loggedIn: true, name: 'Bill'}
  }
  
  onLoggOutClicked = (e) => {
    this.setState({loggedIn:false})
  }
  
  sessionExpired = (e) => {
    this.setState({loggedIn:false, error: 'Expired'})
  }
  
  componentWillUpdate(nextProps, nextState) {
    if (this.state.loggedIn && !nextState.loggedIn) {
      nextState.name = '';
    }
  }
  
  render() {
    // Logout button, Name displayed etc....
  }
}

Thanks @crobinson42 for the response.
The crux is the repetition of name: '' I know it is simplistic here, but it is really a side affect of logging out, not necessarily of say, the session expiring. If I want to change the side affect then I have to update two places.

What do you think of something like this instead of using componentWillUpdate:

onLoggOutClicked = (e) => {
    this.logout()
  }

  sessionExpired = (e) => {
    this.logout();
    this.setState({error: 'Expired'})
  }

logout = () => {
   this.setState(loggedIn: false, name: '')
}

In this case things are DRY, but in the case of session expiry this.setState is called twice. Is that a bad thing? Is there a performance penalty? Is there two render and reconciliation cycles?