Group-By Feature Reques

controllers.application.js

import Ember from 'ember';

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

models.artist.js

import Model from "ember-data/model";
import attr from "ember-data/attr";
import { belongsTo, hasMany } from "ember-data/relationships";

export default Model.extend({
  name: attr('string'),
  category: attr('string'),
});

models.invoice.js

import Model from "ember-data/model";
import attr from "ember-data/attr";
import { belongsTo, hasMany } from "ember-data/relationships";

export default Model.extend({
  lineItems: hasMany()
});

models.line-item.js

import Model from "ember-data/model";
import attr from "ember-data/attr";
import { belongsTo, hasMany } from "ember-data/relationships";

export default Model.extend({
  name: attr('string')
});

routes.index.js

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
    this.store.push({
      data: [
        {
          id: '1',
          type: 'invoice',
          relationships: {
            "lineItems": {
              "data": [
                {
                  "type": "lineItem",
                  "id": "1"
                },
                {
                  "type": "lineItem",
                  "id": "2"
                }
              ]
            }
          }
        }
       ]
    });
      
    return this.store.peekRecord('invoice', 1);
  }
});

templates.application.hbs

{{outlet}}

templates.index.hbs

{{!-- Generates request for lineItems --}}
{{#each model.lineItems as |item|}}
	{{item.name}}
{{/each}}

{{!-- Doesn't generate request and throws error
{{#each-in (group-by "name" model.lineItems) as |name lineItems|}}
  <h1>{{name}} Artists</h1>
  
  <ul>
    {{#each lineItems as |item|}}
      <li>{{item.name}}</li>
    {{/each}}
  </ul>
{{/each-in}}
--}}

twiddle.json

{
  "version": "0.10.4",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.6.0",
    "ember-data": "2.6.0",
    "ember-template-compiler": "2.6.0"
  },
  "addons": {
  	"ember-composable-helpers": "1.0.0"
  }
}