validations-spike

application.controller.js

import Ember from 'ember';

const {
  get,
  computed
} = Ember;

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  errors: computed('model.name', function() {
    let user = get(this, 'model');
    let set = user;
    
    set = presence(set, 'name');
    set = length(set, 'name', { greaterThan: 5 });
    
    return set;
  }),
  
  presence(user) {
    user.changedAttributes()
  }
});

application.route.js

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
    return this.store.createRecord('user', {name: "Hello"});
  }
});

application.template.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
Name: {{input value=model.name}}
{{errors}}
<br>
<br>

models.user.js

import DS from 'ember-data';

const {
  attr
} = DS;

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

twiddle.json

{
  "version": "0.6.4",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "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/2.4.1/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.4.0/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.4.1/ember-template-compiler.js"
  }
}