Add Collection#sort method

Sorts the collection with the function passed as an argument. Works just like Array#find.

Collection#sort will trigger a 'update' event on the collection, making views update automatically.

Example:

  @collection = new Serenade.Collection([{name:'Jonas'}, {name:'CJ'}])
  @collection.sort((a, b) -> if a.name.length < b.name.length then -1 else 1)
  @collection.get(0) # Returns the `{name:'CJ'}` object

spec/collection.spec.coffee

@@ -30,6 +30,18 @@ describe 'Serenade.Collection', ->
       @collection.update([1,2])
       expect(@collection.length).toEqual(2)
 
+  describe '#sort', ->
+    it 'updates the order of the items in the collection', ->
+      @collection.push('a')
+      @collection.sort()
+      expect(@collection.list).toEqual(['a', 'a', 'b', 'c'])
+    it 'updates the order of the items in the collection', ->
+      @collection.sort((a, b) -> if a > b then -1 else 1)
+      expect(@collection.list).toEqual(['c', 'b', 'a'])
+    it 'triggers an update event', ->
+      @collection.sort()
+      expect(@collection).toHaveReceivedEvent('update')
+
   describe '#push', ->
     it 'adds an item to the collection', ->
       @collection.push('g')

src/collection.coffee

@@ -25,6 +25,9 @@ class exports.Collection
     @_in(element) for element in list
     @trigger("update", list)
     @trigger("change", @list)
+  sort: (fun) ->
+    @list.sort(fun)
+    @trigger("update", @list)
   forEach: (fun) ->
     forEach(@list, fun)
   map: (fun) ->