Ultra: The Quest for Zero-Legacy

Code Splitting

Writing and shipping native ESM allows you to take advantage of some pretty neat optimisation features. Dynamic imports and the lazy API can be used to import components on the fly, in a way that is compatible with Suspense.

React Lazy Docs

import { lazy, Suspense } from 'react';

const OtherComponent = lazy(() => import('./OtherComponent.jsx'));

function MyComponent() {
  return (
    <div>
      <Suspense fallback={<div>Loading...</div>}>
        <OtherComponent />
      </Suspense>
    </div>
  );
}

When both server and client rendering this component, the OtherComponent.jsx will only be imported when requested. Native code-splitting? YES!

Hot tip!Using lazy imports with Routing is one of the best things ever