Collection#set uses un-parsed attribute id to determine uniqueness

[bdusell]

Due to limitations in a backend API I am working with, I have a model class whose id attribute is generated by its parse method (it's simply moving a nested attribute up to the top level). I am fetching a collection which may contain models with already exist in the collection. Under normal circumstances, when merge: true is set, I would expect models with the same id to be merged together. However, this will not work when the id attribute is not present in the un-parsed json data, as you can see from the following code in Collection#set:

for (i = 0, l = models.length; i < l; i++) {
  attrs = models[i] || {};
  if (attrs instanceof Model) {
    id = model = attrs;
  } else {
    id = attrs[targetModel.prototype.idAttribute || 'id'];
  }

  // If a duplicate is found, prevent it from being added and
  // optionally merge it into the existing model.
  if (existing = this.get(id)) {

The workaround I have in mind is to override parse in my collection class, and although this will work just fine, it feels a bit unclean and requires some code duplication. Would you consider moving the parsing stage to before the id check? All branches of execution eventually parse the model.

[jridgewell]

Take a look at #3133. It's only on master now, but should be part of v1.2.0.

[akre54]

Yep, that's the feature you want. Thanks @jridgewell