test for a property in ember object
===

Let's say:
 
    Foo.user = Ember.Object.extend({
        username:null,
        name:null,
        loadData:function(data){
            _.each(data, function(value, key){
                console.log(this.hasOwnProperty(String(key)), key, String(key));
                console.log((String(key) in this));
                console.log(key in this.__proto__);
                console.log(_.has(this, key));
                ...
            });
        },
    })

Where data is an Object ex. JSON

Is there any Ember way of testing or just a JS OO way??

Yes it is underscore... ;)
