Merge Vs Assign

components.my-component.js

import Ember from 'ember';

const { assign, computed, get, merge } = Ember;

export default Ember.Component.extend({
  cat: {
    meow: 'purr',
    scratch: 'always',
  },
  
  dog: {
    woof: 'bark',
    scratch: 'sometimes',
  },
  
  animal: computed('cat', 'dog', function() {
    return assign(get(this, 'cat'), get(this, 'dog'));
  })
});

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

My Component<br/>
{{animal.scratch}}<br/>
{{animal.woof}}<br/>
{{animal.meow}}<br/>

twiddle.json

{
  "version": "0.10.6",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.9.0",
    "ember-data": "2.9.0",
    "ember-template-compiler": "2.9.0",
    "ember-testing": "2.9.0"
  },
  "addons": {}
}