Copy Firebase RTDB Node

fbCopy.js

function fbCopy(oldRef, newRef) {    
     return Promise((resolve, reject) => {
          oldRef.once('value').then(snap => {
               return newRef.set(snap.val());
          }).then(() => {
               console.log('Done!');
               resolve();
          }).catch(err => {
               console.log(err.message);
               reject();
          });
     });
}