inheritance of properties not correct

[jneuendorf]

Hi,

when enumerable properties are defined on a class's prototype they are not correctly inherited.
The problem is the generate function.
In case of data descriptors no errors occur but the descriptor be dropped (since only the value will be copied).
In case of accessor descriptors errors can occurs (for example if the getter calls something on this) because

for own key, val of obj
  ...

is compiled to

for (key in obj) {
  if (!hasProp.call(obj, key)) continue;
  val = obj[key];
  ...
}

and val = obj[key] will trigger the getter to be evaluated with the prototype as context instead of the instance.

Object.getOwnPropertyDescriptor(obj, propName) can be used to determine if an attribute is a defined property or not.
This should be used in both loops - maybe like this:

for own key of next
  descriptor = Object.getOwnPropertyDescriptor(next, key)
  if not descriptor?
    value = next[key]
    @[key] = reparent next, @, value
  else
    # I don't know if this really does it
    Object.defineProperty @, key, descriptor

I am not quite sure if Object.defineProperty @, key, descriptor does the job.
However, if the descriptor contains get: () -> this.something or get: () -> this.doSomething() (or a setter) the function body is evaluated when property is accessed so I think everything is fine because at that time heterarchy should have taken care of everything, right?

I guess properties on the class itself behave similarly.

See https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Object/getOwnPropertyDescriptor