$.fn.preempt takes namespaced event names

spec/stdlib/jquery-extensions-spec.coffee

@@ -5,6 +5,7 @@ describe 'jQuery extensions', ->
     [returnValue, element, events] = []
 
     beforeEach ->
+      returnValue = undefined
       element = $("<div>")
       events = []
 
@@ -22,4 +23,19 @@ describe 'jQuery extensions', ->
       it 'does not call subsequent handlers', ->
         returnValue = false
         element.trigger 'foo'
-        expect(events).toEqual [2]
+        expect(events).toEqual [2]
+
+    describe 'when the event is namespaced', ->
+      it 'calls handler', ->
+        element.preempt 'foo.bar', -> events.push(4)
+        element.trigger 'foo'
+        expect(events).toEqual [4,2,1,3]
+
+        events = []
+        element.trigger 'foo.bar'
+        expect(events).toEqual [4]
+
+        events = []
+        element.off('.bar')
+        element.trigger 'foo'
+        expect(events).toEqual [2,1,3]

src/stdlib/jquery-extensions.coffee

@@ -19,5 +19,6 @@ $.fn.preempt = (eventName, handler) ->
   @on eventName, (e) ->
     if handler() == false then e.stopImmediatePropagation()
 
-  handlers = @data('events')[eventName]
+  eventNameWithoutNamespace = eventName.split('.')[0]
+  handlers = @data('events')[eventNameWithoutNamespace]
   handlers.unshift(handlers.pop())