For an example implementation of using different React versions together with Module Federation, check out the runtime plugin folder runtime-plugins/multiple-react-versions.

Mixed React Versions and Compatibility levels

This example demos the ability to load two separate versions of react (v16.6.3 and v18.2.0).

Read more about TypeScript and Federation: https://module-federation.io/guide/basic/type-prompt.html

Check the javascript version of this example here.

Module Federation allows us to create an adapter which attaches a hooks-friendly version to render a section of thr app using modern versions.

• app1 uses and older version of react, not compatible with react Hooks
• app2 uses a modern react version and its components are hooks based

Running Demo

Run pnpm run start. This will build and serve both app1 and app2 on ports 3001 and 3002 respectively.

• localhost:3001 (HOST)
• localhost:3002 (STANDALONE REMOTE)

How it works

This example contains two important components, the ReactAdapterConsumer and ReactAdapterProvider. They are responsible to make the two versions of react work together.

The adapter consumes both versions of react to "translate" the props into a fresh render. This could be presented as a HOC or federated components could have a legacy export containing the adapter build in.

ReactAdapterProvider

This component is responsible to dynamic render/hydrate the federated component using it host version of React.

You can see the usage here.

This is a generic component type, so you can pass the generic parameter to the component to specify the type of the props.

import React from 'react';

export interface ButtonProps {
  color: 'red' | 'blue';
}

const Button = (props: ButtonProps) => {
  return <button style={{ color: props.color }}>Click me</button>;
};

export const Adapted = React.forwardRef<
    ReactAdapterProvider<ModernReactComponentProps>,
    ModernReactComponentProps
  >((props, ref) => {
  // the intellisesne will show the type of the props if you try to modify it
  return (
    <ReactAdapterProvider<ButtonProps> component={Button} color="red" ref={ref} />
  );
});

ReactAdapterConsumer

This component is responsible to render the federated component using the remote version of React.

You can see the usage here.

This is a generic component type, so you can pass the generic parameter to the component to specify the type of the props.

// remeber to add path alias to your tsconfig.base.json at the root of the workspace and the type definition file of the remote component
// Read more here: https://module-federation.io/guide/basic/type-prompt.html
import type { ButtonProps } from 'app2/Button';

<ReactAdapterConsumer<ButtonProps>
  // you can try to modify the color value and the intellisense automatically will show the type of the props
  color="blue"
  fallback={<div>Loading...</div>}
  importer={() => import('app2/Button').then(module => ({ default: module.Adapted }))}
/>;