             )
 
             =>
-                if not @hasKey key
+                if not @hasKey key, false
                     # This field has just been deleted
                     return J.makeValueNotReadyObject()
 



    getKeys: ->
        @_keysVar.get()


    hasKey: (key) ->
        if @_keysVar._value is undefined or @_keysVar._invalidAncestors.length
            # This might have a special @_replaceKeys side effect
            # which then makes the logic in super work

            @_hasKeyDeps[key] ?= new Tracker.Dependency @creator
            @_hasKeyDeps[key].depend()

        if _filtered and @filterFunc?
            key of @_fields and @tryGet(key) isnt undefined
        else
            key of @_fields


    isActive: ->
