LSAdapter includes test

adapters.application.js

import LSAdapter from 'ember-localstorage-adapter';

export default LSAdapter.extend({
  namespace: 'twiddle_demo_namspace'
});

controllers.application.js

import Ember from 'ember';
import { computed } from '@ember/object';
import { alias } from '@ember/object/computed';
import { inject as service } from '@ember/service';

export default Ember.Controller.extend({
  store: service(),
  appName: 'localStorage adapter relationship test',

  init() {
    this._super(...arguments);
    console.log('ApplicationController -->', this);
  },
  
  showWarningMessage: false,
  parents: alias('model'),
  children: computed('model.@each.children.[]', function() {
    const children = Array.prototype.concat(...this.model.mapBy('children').map(c => c.toArray()));
    console.log('computed children; names =', children.mapBy('name'));
    return children;
  }),
  grandchildren: computed('children.@each.children.[]', function() {
    const grandchildren = Array.prototype.concat(...this.children.mapBy('children').map(c => c.toArray()));
    console.log('computed grandchildren; favoriteColors =', grandchildren.mapBy('favoriteColor'));
    return grandchildren;
  }),
  
  numParents: alias('parents.length'),
  numChildren: alias('children.length'),
  numGrandchildren: alias('grandchildren.length'),
});

models.child.js

import Model from 'ember-data/model';
import attr from 'ember-data/attr';
import { hasMany } from 'ember-data/relationships';

export default Model.extend({
  name: attr('string'),
  children: hasMany('grandchild', { async: false })  
});

models.grandchild.js

import Model from 'ember-data/model';
import attr from 'ember-data/attr';

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

models.parent.js

import Model from 'ember-data/model';
import { hasMany } from 'ember-data/relationships';

export default Model.extend({
  children: hasMany('child', { async: false })
});

routes.application.js

import Ember from 'ember';


const names = Object.freeze([
  'Alice',
  'Bob',
  'Carl',
  'Deb',
  'Eliza',
  'Fred',
  'George',
  'Henrietta',
  'Ivan',
]);
let nameIndex = 0;

const colors = Object.freeze([
  'Red',
  'Orange',
  'Yellow',
  'Green',
  'Blue',
  'Indigo',
  'Violet',
  'White',
  'Black',
  'Fushia',
  'Teal',
  'Pink',
  'Cyan',
]);
let colorIndex = 0;

export default Ember.Route.extend({
  model() {
    console.log('model running');
  	return this.store.findAll('parent');
  },
  afterModel() {
    this._super(...arguments);
    console.log('afterModel running');
    // Initializing store (could do elsewhere)
    this.store.findAll('parent').then(parents => {
      if (parents.length < 1) {
        const parents = new Array(2).fill(0).map((z,i) => {
          const parent = this.store.createRecord('parent', { 
            children: new Array(4).fill(0).map((z,i) => {
              const child = this.store.createRecord('child', {
                name: names[nameIndex++ % names.length],
                children: new Array(2).fill(0).map((z,i) => {
                  const grandchild = this.store.createRecord('grandchild', {
                    favoriteColor: colors[colorIndex++ % colors.length]
                  }); // grandchild
                  grandchild.save();
                  return grandchild;
                }) // grandchildren
              }); // child
              child.save();
              return child;
            }) // children
          }); // parent
          parent.save();
          return parent;
        }); // forEach
        Promise.all(parents.map(p => p.save())).then(() => {
          console.log('About to reload to avoid confusion related to just having primed the store.');
          // FIXME: Always get stuck here since it seems we can't write to localStorage
          //debugger;
          //window.location.reload();
          this.controllerFor('application').set('showWarningMessage', true);
        });
      } // if      
    }); // findAll
  }
});

serializers.application.js

import { LSSerializer } from 'ember-localstorage-adapter';

export default LSSerializer.extend();

templates.application.hbs

{{#if showWarningMessage}}
<h1 style="background-color: orange">Store initialized -- need to reload and fetch from localStorage for this demo to work</h1>
{{/if}}
<h1>{{appName}}</h1>
{{numParents}} parent(s)<br>
{{numChildren}} child(ren)<br>
{{numGrandchildren}} grandchild(ren)<br>
<ul>
  {{#each parents as |parent parentIndex|}}
  	<li>
    	Parent #{{parentIndex}}
      <ul>
        {{#each parent.children as |child|}}
          <li>
          	{{child.name}}
          	<ul>
              {{#each child.children as |grandchild|}}
                <li>{{grandchild.favoriteColor}}</li>
              {{/each}}
            </ul>
     		  </li>
        {{/each}}
      </ul>
		</li>
  {{/each}}
</ul>

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-data": "3.4.2",
    "ember-localstorage-adapter": "1.0.0"
  }
}