Error on npm start -s "missing class properties transform" using ES6 style classes

Node version: 6.10.1

npm version: 3.10.10

Operating system: OS X Sierra

Command line used: npm start -s

Steps to reproduce: create an ES6 Class like so, and run npm start -s. An error is produced claiming “missing class properties transform”. This happens for both propTypes, defaultProps, contextTypes and any custom methods/properties I have defined (like _updateDocumentTitle).

class Navigation extends React.Component {
  static propTypes = {};
  static defaultProps = {};
  static contextTypes = {
    router: object.isRequired
  }

  componentDidMount () {
    this._updateDocumentTitle();
  }

  componentDidUpdate () {
    this._updateDocumentTitle();
  }

  _updateDocumentTitle = () => {
    // .. do some junk
  }

  render () {
    return (<span>Foo</span>);
  }
}

[kwelch]

I have a repo I built out for a local user group that have tests using jest/enzyme, it just lacks a component. It may be of help. https://github.com/NashReact/jest-exercises/tree/master/exercises/13 - Component Testing

[mikedevita]

Thanks man right up my alley on what I needed!