computed bug

components.my-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  someArray: Ember.computed(function() {
    const arr = Ember.A([]);
    arr.pushObject(Ember.Object.create({
      zero: 0,
      someProp: 'zero',
    }));
                   
    return arr;
  }),

  someComputed: Ember.computed('someArray.0.someProp', function() {
    return this.get('someArray.0.someProp');
  }),
  
  actions: {
    addSomething() {
      this.get('someArray').pushObject(Ember.Object.create({
        one: 1,
        someProp: 'one',
      }));
    },
                      
    removeSomething() {
      this.get('someArray').removeAt(0);
    },
  },
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

templates.application.hbs

{{my-component}}

templates.components.my-component.hbs

Array: {{someArray.length}}
Computed: {{someComputed}}
<button {{action "addSomething"}}>click to add</button>
<button {{action "removeSomething"}}>click to remove</button>

twiddle.json

{
  "version": "0.10.7",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.10.0",
    "ember-data": "2.10.0",
    "ember-template-compiler": "2.10.0",
    "ember-testing": "2.10.0"
  },
  "addons": {}
}