Why does my component re-render?

wrapper.js

// helper for debugging why your (pure) component is re-rendering
const wrapper = (Cmp) => (props) => {
  if (wrapper.prevProps) {
    console.log('re-rendering', Cmp.name);
    Object.keys(props)
      .filter(k => wrapper.prevProps[k] !== props[k])
      .forEach(k => console.log(k, wrapper.prevProps[k], props[k]));
  }
  wrapper.prevProps = props;
  return <Cmp {...props} />
}

export default wrapper;