@loadable/babel-plugin/src/properties/requireAsync.js

Babel plugin for loadable (required for SSR).

export default function requireAsyncProperty({ types: t, template }) {
  const tracking = template.ast(`
    const key = this.resolve(props)
    this.resolved[key] = false
    return this.importAsync(props).then(resolved => {
     this.resolved[key] = true
     return resolved;
    });        
  `)

  return () =>
    t.objectMethod(
      'method',
      t.identifier('requireAsync'),
      [t.identifier('props')],
      t.blockStatement(tracking),
    )
}