type Listener = ( ) => void ; type Listeners = Record < string , Listener > ; export function subscribe ( node , listeners ) { let subscriptions = listen ( node , listeners ) ; return { update ( listeners ) { unsubscribe ( subscriptions ) ; subscriptions = listen ( node , listeners ) ; } , destroy ( ) { unsubscribe ( subscriptions ) ; } } ; } function listen ( node , listeners ) { if ( ! listeners ) return [ ] ; return Object . keys ( listeners ) . map ( ( event ) => { const handler = listeners [ event ] ; node . addEventListener ( event , handler ) ; return ( ) => node . removeEventListener ( event , handler ) ; } ) ; } function unsubscribe ( subscriptions ) { return subscriptions . forEach ( ( unsubscribe ) => unsubscribe ( ) ) ; }