EventEmitter.off with no args removes all subscriptions

spec/app/event-emitter-spec.coffee

@@ -52,6 +52,13 @@ describe "EventEmitter mixin", ->
       object.trigger('junk.garbage')
 
   describe ".off", ->
+    describe "when called with no arguments", ->
+      it "removes all subscriptions", ->
+        object.off()
+        object.trigger 'foo'
+        expect(fooHandler1).not.toHaveBeenCalled()
+        expect(fooHandler2).not.toHaveBeenCalled()
+
     describe "when called with a non-namespaced event name", ->
       it "removes all handlers for that event name", ->
         object.off 'foo'

src/app/event-emitter.coffee

@@ -24,13 +24,16 @@ module.exports =
     else
       @eventHandlersByEventName?[eventName]?.forEach (handler) -> handler(event)
 
-  off: (eventName, handler) ->
+  off: (eventName='', handler) ->
     [eventName, namespace] = eventName.split('.')
-    eventName = undefined if eventName is ''
+    eventName = undefined if eventName == ''
 
     subscriptionCountBefore = @subscriptionCount()
 
-    if namespace
+    if !eventName? and !namespace?
+      @eventHandlersByEventName = {}
+      @eventHandlersByNamespace = {}
+    else if namespace
       if eventName
         handlers = @eventHandlersByNamespace?[namespace]?[eventName] ? []
         for handler in new Array(handlers...)