Calypso Async Babel Transform Plugin

babel-plugin-transform-wpcalypso-async is a Babel plugin to facilitate optional code-splitting by applying transformations to a asyncRequire global function or the <AsyncLoad /> React component.

Usage

Include in your Babel configuration as a plugin.

Example Babel config file:

{
    "plugins": [ "@automattic/transform-wpcalypso-async" ]
}

See Babel options documentation for more information.

Transformations

asyncRequire will transform to one of:

dynamic import() if the ignore plugin option is not true
a rejected Promise that throws an error that the import is ignored, if the ignore plugin option is true

asyncRequire expects one required argument, the name of the imported module.

asyncRequire( 'calypso/components/search' ).then( ( { default: Search } ) => {
    console.log( Search );
} );

<AsyncLoad /> will transform its require string prop to a function invoking a dynamic import, or throwing an error when the ignore option is enabled.

// Before:

<AsyncLoad require="calypso/components/search" />;

// After:
const ref = () => import( 'calypso/components/search' );

<AsyncLoad require={ ref } />;

Options

ignore - if set to true, the asyncRequire call will be returning a rejected Promise, and AsyncLoad will show the placeholder forever and won't do any import. Useful for server side rendering where the render is one-pass and doesn't wait for any imports to finish.