DDAU with slow deserializer

components.slow-component.js

import Ember from 'ember';

const { get, computed } = Ember;

function serialize(val) {
  return JSON.stringify(val);
}

function deserialize(val) {
  console.log('deserializing, this takes a long time...');
  return JSON.parse(val);
}

export default Ember.Component.extend({
  parsedValue: computed('value', function() {
    return deserialize(get(this, 'value'));
  }),

  actions: {
    update() {
      let parsedValue = get(this, 'parsedValue');

      parsedValue.push(Math.random()+"");

      let storedValue = serialize(parsedValue);
      get(this, 'onupdate')(storedValue);
    }
  }
});

controllers.application.js

import Ember from 'ember';

const { set } = Ember;

export default Ember.Controller.extend({
  value: '["hello","there"]',

  actions: {
    update(value) {
      set(this, 'value', value);
    }
  }

});

templates.application.hbs

<h1>Parser Round Trip Test</h1>
<p>
This test app uses DDAU, but includes an editing component that has a very slow parse/serialize step that we'd like to avoid. Normal DDAU means pushing the serialized value to the parent and then having the component re-parse, how can we avoid the re-parse?
</p>

<p>
{{slow-component value=value onupdate=(action 'update')}}
</p>

templates.components.slow-component.hbs

<p>
  parsed: {{parsedValue}}
</p>

<p>
  raw: <pre>{{value}}</pre>
</p>

<p>
  <button {{action 'update'}}>update</button>
</p>

twiddle.json

{
  "version": "0.11.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.10.2",
    "ember-data": "2.11.0",
    "ember-template-compiler": "2.10.2",
    "ember-testing": "2.10.2"
  },
  "addons": {}
}