array problem

controllers.application.js

import Ember from 'ember';

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

helpers.array-contains.js

import Ember from 'ember';

export function arrayContains(params, namedArgs) {
    let array = namedArgs.array || [],
        key = namedArgs.key || '';
    console.log('contains', array, key)
    return array.contains(key);
}

export default Ember.Helper.helper(arrayContains);

router.js

import Ember from 'ember';
import config from './config/environment';

const Router = Ember.Router.extend({
  location: 'none'
});

Router.map(function() {
  this.route('my-route')
});

export default Router;

routes.index.js

import Ember from 'ember'

export default Ember.Route.extend({
    redirect() {
        this.transitionTo('my-route')
    }
})

routes.my-route.js

import Ember from 'ember';

const RoleAssignment = Ember.Object.extend({
   computedRoles: Ember.computed('roles.[]', function() {
          return this.get('roles')
  	})
})

export default Ember.Route.extend({
  actions: {
        selectRole(member, role) {
          
            let memberRoles = Ember.get(member, 'roles');

            if (memberRoles.contains(role)) {
              Ember.set(member, 'roles', memberRoles.without(role))
            } else {
                memberRoles.pushObject(role);
            }
        }
    },
  
  model: function() {
    return {
      roleAssignment: RoleAssignment.create({
        "id": "4-8261",
        "user": {
            "id": 8261,
            "last_login": "2015-09-02T14:32:41+0200",
            "email": "assaaas",
            "first_name": "Majid",
            "last_name": "Mvulle"
        },
        "roles": [
            "access-plan",
            "invitation",
            "policy",
            "team",
            "permission"
        ]
    	}),
      rolesList: [{"id":"access-plan","label":"Access any plan"},
                  {"id":"invitation","label":"Invite new members"},{"id":"policy","label":"Manage policies"},{"id":"team","label":"Manage team"},{"id":"permission","label":"Manage user permissions"}]
           }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
<br>
<br>

templates.my-route.hbs

 gdfg   <ul class="list-unstyled">
        {{#each model.rolesList as |role index|}}
            <li><button {{action "selectRole" model.roleAssignment role.id}}>Toggle</button>
                {{array-contains array=model.roleAssignment.computedRoles key=role.id}} 
                {{role.label}}
            </li>
        {{/each}}
                
    </ul>
<ul>
{{#each model.roleAssignment.roles as |role|}}
  <li>
    {{role}}
  </li>
{{/each}}
</ul>

twiddle.json

{
  "version": "0.7.2",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.4.4/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.4.3/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.4.4/ember-template-compiler.js"
  }
}