Illegal return statement in JavaScript

Question

A \'days\' node with more than 1 child isn\'t getting removed. How can I fix this issue?

I need to ensure that my promise bubbles up to the last then() on the top-level

Answer 1

exports.deleteOldItems = functions.database.ref('/path/to/items/{pushId}')
  .onWrite(event => {
    var ref = event.data.ref.parent // reference to the items
    var now = Date.now()
    var cutoff = now - 2 * 60 * 60 * 1000
    var oldItemsQuery = ref.orderByChild('timestamp').endAt(cutoff)
    return oldItemsQuery.once('value', function(snapshot) {
      // create a map with all children that need to be removed
      var updates = {}
      snapshot.forEach(function(child) {
        updates[child.key] = null
      })
      // execute all updates in one go and return the result to end the function
      return ref.update(updates)
    }).then(function() {
      // const theRef = event.data.ref
      const collectionRef = defaultDatabase.ref().child('/days')
      // return collectionRef // ILEGAL RETURN STATEMENT
      collectionRef.once('value').then(messagesData => {
                console.log(`Hello messageData : ${messagesData.numChildren()}`)
              if(messagesData.numChildren() > 1) {
                    const updates = {}
                    updates['/days'] = null
                    return defaultDatabase.ref().update(updates); // 'days' doesn't get removed even if it has more than 1 child (as in the image)!
                }
      })
  })

use defaultDatabase.ref().child('/days') instead of using event.data.ref.parent

also please go through the documentation and learn how promises works it will help you future. For now these changes will work.Tested at my end.

videos you must watch

What's the difference between event.data.ref and event.data.adminRef? - #AskFirebase Asynchronous Programming (I Promise!) with Cloud Functions for Firebase - Firecasts

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