deleteRecord : recordWillDelete actually update the belongTo parent on firebase, causing crash

[olivierchatry]

Version info

Latest version ( 2.0.8 )

Test case

This is hard to reproduce as it depends on user input, network lag, and direction of the wind.

Steps to reproduce

Delete a record while having user input or heavyload.

Expected behavior

No error on the console

Actual behavior

Error saying that record cannot be deleted because state is updated.

Explaination :

This is a funny one. Basically recordWillDelete ( function called before actual deletion ) will update directly the parent on all belongsTo relation

    recordWillDelete: function recordWillDelete(store, record) {
      var _this2 = this;

      record.eachRelationship(function (key, relationship) {
        if (relationship.kind === 'belongsTo') {
          var parentRecord = record.get(relationship.key);
          var inverseKey = record.inverseFor(relationship.key);
          if (inverseKey && parentRecord.get('id')) {
            var parentRef = _this2._getCollectionRef(inverseKey.type, parentRecord.get('id'));
            _this2._removeHasManyRecord(store, parentRef, inverseKey.name, record.constructor, record.id);
          }
        }
      });
    },
    _removeHasManyRecord: function _removeHasManyRecord(store, parentRef, key, typeClass, id) {
      var relationshipKey = store.serializerFor(typeClass.modelName).keyForRelationship(key);
      var ref = this._getRelationshipRef(parentRef, relationshipKey, id);
      return (0, _emberfireUtilsToPromise['default'])(ref.remove, ref, [], ref.toString());
    },

Since everything is done async, from time to time, the loopback of the parent set value will actually modify the record you are trying to delete ( I guess trying to set the parent to null ), right before deletion, so the state will not be valid anymore.

If I understand correctly, it is anyway the responsability of the user to "save" the parent value on modification, so emberfire should not do what it does ( or at least not modify the record value while in deletion).

Not sure if it is understandable, but what I did was to simply override the willDeleteRecord in the application adapter by that :

	recordWillDelete: function recordWillDelete(store, record) {
		// here we are doing nothing. Emberfire try to update parent for belongTo relationship directly
		// on firebase, which would lead sometimes to an error as the child get updated, while we delete it
		// when the parent receive the loopback from firebase.
	},

and no more issue

[olivierchatry]

It is also written in the documentation, that you need to save both side :
https://github.com/firebase/emberfire/blob/master/docs/guide/relationships.md