Lazy Loading error check

lazy-loading-error-check.ts

// inspired by https://dev.to/goenning/how-to-retry-when-react-lazy-fails-mb5 
const ValueSet = React.lazy(() =>
  lazyCheck(() => import('../routes/ValueSet/ValueSet'))
)

function lazyCheck(fn: Function): Promise<{ default: ComponentType<any> }> {
  return new Promise((resolve, reject) => {
    fn()
      .then(resolve)
      .catch((error: Error) => {
        console.log('catching w/ lazy loading', error)
      })
  })
}