model.changedAttributes() behaves inconsistently

[cibernox]

I've observed that DS.Model.changedAttributes() behaves differently on new records than on saved ones (the behaviour on the saved models looks correct to me, the one in the new records seems as bug)

If you create a new record and change some of its attributes, model.changedAttributes() will return an object with the properties that have changed and the current and previous value, and model.isDirty is true. So far so good.

But when you save it, while the request is pending and the record is still being saved, on the new record the changed attributes is cleared (an empty object), while on the already saved record it the changed attributes don't change until the save operation completes.

The behaviour of the saved records seems the right one. The dirty attributes should remain dirty until we get confirmation from the API).

In both cases the record's isDirty property is true, is just the changedAttributes() function the one that returns the wrong value.

Reproducible live example: http://development.dummy-app.divshot.io/ember-data-dirty-bug
Code: https://github.com/cibernox/dummy-app-for-benchmark

Also I'm curious about why changedAttributes is a function and not a computedProperty.

[cibernox]

Just for the record, I've fixed this myself. I'm struggling a bit to add a proper test harness bug hopefully I should have a fix tonight.