Incorrect Results Delete Change Notifications

[509dave16]

Goals

• Provision of correct fine grained change notifications for Results instances upon deletes.
  1. Expected Results
• I expected that upon removing the first instance from a Results instance like this

const firstObjectOfType = realm.objects('Dog')[0];
realm.write(() => {
  realm.delete(firstObjectOfType);
});

• I would get this for changes notifications:

{
  insertions: [],
  deletions: [0],
  modifications: []
}

Actual Results

• Instead I got this for changes notifications

{
  insertions: [0],
  deletions: [0, <index of last element(i.e. if length 3 then index 2)>],
  modifications: []
}

• This is occurring for Results whose length is greater than 2 for whatever reason.
• So it only works for a Results set of lengths 1 and 2.

Steps to Reproduce

• With provided code sample or one of your own do the following:
  • Add at least 3 objects of a type(i.e. click the Add Rex button 3 times)
  • Remove the first resource(i.e. click the Remove First button 1 time)
  1. Code Sample
• Gist of Root Component to Register with React Native

Version of Realm and Tooling

• Realm JS SDK Version: 2.0.12
• Node: 8.6.0
• React Native: 0.50.4
• Client OS & Version: 10.12.6
• Which debugger for React Native: Chrome Remote Debugger