Contrived CP example

controllers.application.js

import Ember from 'ember';

function makeCP(keys, cb) {
  keys = keys.map(key => `someObj.${key}`);
  
  const args = [...keys, cb];
  return Ember.computed(...args);
}

const someObj = {
  thePeople: 'are real',
  theCases: 'are real',
  theRulings: 'are final'
};

const theKeys = Object.keys(someObj);

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  foo: makeCP(theKeys, function() {
    return this.get('someObj.thePeople');
  }),
  someObj
});

templates.application.hbs

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

<input oninput={{action (mut someObj.thePeople) value="target.value"}}>
<br>
<br>

twiddle.json

{
  "version": "0.10.4",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.7.0",
    "ember-data": "2.7.0",
    "ember-template-compiler": "2.7.0"
  },
  "addons": {}
}