Collect data by category (Pets by type)

controllers.application.js

import Ember from 'ember';
import { computed } from '@ember/object';

const data = [{
  type: 'cat',
  name: 'fluffy'
}, {
  type: 'dog',
  name: 'bowser'
}, {
  type: 'dog',
  name: 'roxie'
}];

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  pets: data,
 
  petsByType: computed(function() {
    let pets = this.get('pets');
    let types = pets.reduce((buckets, pet) => {
	  	let bucket = buckets.findBy('name', pet.type);
	  	if(bucket){
	  	  bucket.pets.pushObject(pet);
	  	} else {
	  	  buckets.pushObject({ name: pet.type, pets: [pet]});
	  	}
	  	return buckets;
		}, []);
    return types;
  })
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{#each pets as | pet |}}
  <div>{{pet.type}} - {{pet.name}}</div>
{{/each}}
<hr>
{{#each petsByType as | type |}}
  <b>{{type.name}}</b>
  {{#each type.pets as | pet |}}
	  <div>{{pet.name}}</div>
	{{/each}}
{{/each}}
{{outlet}}
<br>
<br>

twiddle.json

{
  "version": "0.15.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.2.2",
    "ember-template-compiler": "3.2.2",
    "ember-testing": "3.2.2"
  },
  "addons": {
    "ember-data": "3.2.0"
  }
}