Collection.add return value no longer the same as Backbone.Collection's

[mlilley]

According to the Backbone docs, Collection.add() returns the added model (or array of models when adding multiple), and the changelog says this changed for all of set, add, remove, and reset in version 1.1 (previous behaviour was to return the collection).

Issue #412 and associated fix 285161e shows some work was done on this to bring backbone-relational into line (specifically for set) in master.

Unfortunately either add didn't get the same love, or the fix didn't work completely -- I'm seeing add return an array in both cases, instead of just the model when adding a single item (using backbone-relational master).

I haven't checked whether set, remove, and reset are likewise affected.

[mlilley]

Yeah, ok, I'm seeing the issue for all 4 functions.

Here's some quick and dirty code showing the problems:
(change Car to extend Backbone.Model, and the return values differ)

var Car  = Backbone.RelationalModel.extend({ });
var Cars = Backbone.Collection.extend({ model: Car });
var cars = new Cars();

console.log(cars.add({name:'A'}));                  // returns [model] (should not be array)
console.log(cars.add([{name:'B'},{name:'C'}]));     // returns [model,model] (OK)

console.log(cars.remove(cars.at(0)));               // returns [model] (should not be array)
console.log(cars.remove([cars.at(0), cars.at(1)])); // returns [model,model] (OK)

console.log(cars.reset({name:'D'}));                // returns [model] (should not be array)
console.log(cars.reset([{name:'E'},{name:'F'}]));   // returns [model,model] (OK)

var e = cars.at(0), f = cars.at(1);
console.log(cars.set(e));                           // returns [model] (should not be array)
console.log(cars.set([e,f]));                       // returns [model,model] (OK)

[mlilley]

Fiddle: http://jsfiddle.net/RrAsW/

[PaulUithol]

This was the correct behavior for Backbone 1.0. Backbone 1.1 adds different behavior when 'single' models are added to a collection.

[lsimoneau]

Any chance of seeing a new release with this fix? Cheers.

[PaulUithol]

Yep, I'm looking a couple more issues I'd like to fix before creating a new release. Won't be too long (well, I hope ;).