Fix specs

spec-nylas/stores/focused-contacts-store-spec.coffee

@@ -3,6 +3,7 @@ Reflux = require 'reflux'
 
 MessageStoreStub = Reflux.createStore
   items: -> []
+  extensions: -> []
   threadId: -> null
 
 NamespaceStoreStub = Reflux.createStore

src/flux/stores/message-store.coffee

@@ -52,7 +52,6 @@ MessageStore = Reflux.createStore
   # - `ext` A {MessageStoreExtension} instance.
   #
   registerExtension: (ext) =>
-    @_extensions ?= []
     @_extensions.push(ext)
 
   # Public: Unregisters the extension provided from the MessageStore.
@@ -65,12 +64,13 @@ MessageStore = Reflux.createStore
 
   ########### PRIVATE ####################################################
 
-  _setStoreDefaults: ->
+  _setStoreDefaults: =>
     @_items = []
     @_itemsExpanded = {}
     @_itemsLocalIds = {}
     @_itemsLoading = false
     @_thread = null
+    @_extensions = []
     @_inflight = {}
 
   _registerListeners: ->

src/flux/stores/workspace-store.coffee

@@ -138,6 +138,7 @@ class WorkspaceStore
   # Public: Returns a {Boolean} indicating whether the location provided is hidden.
   # You should provide one of the WorkspaceStore.Location constant values.
   isLocationHidden: (loc) =>
+    return false unless loc
     @_hiddenLocations[loc.id]
 
   ###