snippet to debug unexpected pure component updates

debugPureComponent.js

componentDidUpdate(prevProps, prevState) {
  const diff = (o1, o2) => (
    _.map(_.filter(_.uniq([..._.keys(o1), ..._.keys(o2)]), key => o1[key] !== o2[key]), key => ({
      key,
      v1: o1[key],
      v2: o2[key],
    }))
  );
  console.log('DIFF', { props: diff(prevProps, this.props), state: diff(prevState, this.state) });
}