Angularfire: Querying lists doesn't return every result on changes

[antti-pyykkonen]

Version info

Angular: 2.4.3

Firebase: 3.6.0

AngularFire: 2.0.0-beta.7

How to reproduce these conditions

Steps to set up and reproduce

Plnkr example of the issue

FirebaseListObservable doesn't always return all the queried items. When we use query options like startAt & orderByChild.

1. Add the code below to your project and the data to Firebase

2. Start changing the order properties from positive to negative and back again from Firebase console

3. At some point the number of items returned will differ

Here's a reproducable example that you can test:

// ANGULARFIRE
this.af.database.list('order_testing', {
  query: {  
    orderByChild: 'order',  
    startAt: 0  
 }
}).subscribe(x => console.log('ANGULARFIRE:', x.length));

// FIREBASE
this.af.database.list('order_testing').$ref.orderByChild('order').startAt(0).on('value', (x) => {
   console.log('FIREBASE:', Object.keys(x.val()).length)
});

Sample data and security rules

Here's the data located under order_testing in Firebase

{
  "obj1" : {
    "order" : 1
  },
  "obj2" : {
    "order" : 2
  },
  "obj3" : {
    "order" : 3
  },
  "obj4" : {
    "order" : 4
  },
  "obj5" : {
    "order" : 5
  }
}

Debug output

FIREBASE: 5  
ANGULARFIRE: 5

// After changing some ordering to negative and back to positive the number of items will differ

FIREBASE: 5  
ANGULARFIRE: 4

Expected behavior

The logged values from Angularfire & Firebase should remain the same after changes to order property

Actual behavior

The logged values from Angularfire & Firebase are not the same after changing the order property

[davideast]

Thank you for the detailed write-up! Can I also trouble you for a plnkr? We have a template here: http://plnkr.co/edit/8yY4tH?p=preview

This will ensure we're tackling the same problem and make it much easier for me to debug.

[antti-pyykkonen]

Hey! I've made a plnkr available for you. See if it helps: http://plnkr.co/edit/9UzrMSHPowJ1K4zMbiQz?p=preview

[cartant]

@antti-pyykkonen This looks very much like the problem that was addressed in PR #775.

[davideast]

@cartant @antti-pyykkonen I'll be cutting a next release soon. I'll update this thread when it's out.

[davideast]

@cartant I'm trying to find your contact info, but you a hard person to find! Send me an email to [email protected], and let's talk about some AF2 :)

[antti-pyykkonen]

I believe this is now solved?

[davideast]

@antti-pyykkonen Yes it is!