ember-validated-form with custom textareas

controllers.application.js

import Ember from 'ember';
import UserValidations from 'twiddle/validations/user';

export default Ember.Controller.extend({
  UserValidations,
  
  model: {
  	firstName: '',
    lastName: ''
  },

  actions: {
    submit(model) {
      console.log('submit', model)
    }
  }
});

templates.application.hbs

{{#validated-form
	model=(changeset model UserValidations)
  on-submit    = (action "submit")
  submit-label = 'Save' as |f|}}
  
  {{#f.input label="First name" name="firstName" as |fi|}}
    {{textarea
      value=fi.value
      input=(action fi.update value="target.value") 
      focus-out=fi.setDirty}}
  {{/f.input}}
  
  {{#f.input label="Last name" name="lastName" as |fi|}}
    <textarea
     oninput={{action fi.update value="target.value"}} 
     onblur={{action fi.setDirty}}>{{fi.value}}</textarea>
  {{/f.input}}
  
  {{f.submit label="Save"}}
{{/validated-form}}

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1",
    "ember-validated-form": "0.4.0"
  }
}

validations.user.js

import {
  validatePresence,
  validateLength,
  validateInclusion
} from 'ember-changeset-validations/validators';

export default {
  firstName: [validatePresence(true), validateLength({ min: 3, max: 40 })],
  lastName: [validatePresence(true), validateLength({ min: 3, max: 40 })]
};