spec_app/spec/javascripts/up/popup_spec.js.coffee in unpoly-rails-0.23.0 vs spec_app/spec/javascripts/up/popup_spec.js.coffee in unpoly-rails-0.24.0

@@ -71,10 +71,10 @@
 
     describe 'a[up-popup]', ->
 
       beforeEach ->
         @$link = affix('a[href="/path"][up-popup=".target"]')
-        @attachSpy = up.popup.knife.mock('attach')
+        @attachSpy = up.popup.knife.mock('attach').and.returnValue(u.resolvedPromise())
         @defaultSpy = up.link.knife.mock('allowDefault').and.callFake((event) -> event.preventDefault())
 
       it 'opens the clicked link in a popup', ->
         Trigger.click(@$link)
         expect(@attachSpy).toHaveBeenCalledWith(@$link)