Revise test decorator used in TestPageEditHandlers

- Fix clear_edit_handler decorator
- Will  allow the TestPageEditHandlers test cases to run
- Fixes test for test_check_invalid_base_form_class
- Errors might be returned out of order, so sort them before comparing them to the expected list

CHANGELOG.txt

@@ -10,6 +10,7 @@ Changelog
  * Fix: ModelAdmin no longer fails when filtering over a foreign key relation (Jason Dilworth, Matt Westcott)
  * Fix: The Wagtail version number is now visible within the Settings menu (Kevin Howbrook)
  * Fix: Scaling images now rounds values to an integer so that images render without errors (Adrian Brunyate)
+ * Fix: Revised test decorator to ensure TestPageEditHandlers test cases run correctly (Alex Tomkins)
 
 
 2.5 (24.04.2019)

docs/releases/2.6.rst

@@ -24,6 +24,7 @@ Bug fixes
  * ModelAdmin no longer fails when filtering over a foreign key relation (Jason Dilworth, Matt Westcott)
  * The Wagtail version number is now visible within the Settings menu (Kevin Howbrook)
  * Scaling images now rounds values to an integer so that images render without errors (Adrian Brunyate)
+ * Revised test decorator to ensure TestPageEditHandlers test cases run correctly (Alex Tomkins)
 
 
 Upgrade considerations

wagtail/admin/tests/test_edit_handlers.py

@@ -1,4 +1,5 @@
 from datetime import date
+from functools import wraps
 from unittest import mock
 
 from django import forms
@@ -121,14 +122,16 @@ class TestGetFormForModel(TestCase):
 
 def clear_edit_handler(page_cls):
     def decorator(fn):
-        def decorated(self):
+        @wraps(fn)
+        def decorated(*args, **kwargs):
             # Clear any old EditHandlers generated
             page_cls.get_edit_handler.cache_clear()
             try:
-                fn(self)
+                fn(*args, **kwargs)
             finally:
                 # Clear the bad EditHandler generated just now
                 page_cls.get_edit_handler.cache_clear()
+        return decorated
     return decorator
 
 
@@ -182,6 +185,9 @@ class TestPageEditHandlers(TestCase):
             # don't build the CSS)
             errors = [e for e in errors if e.id != 'wagtailadmin.W001']
 
+            # Errors may appear out of order, so sort them by id
+            errors.sort(key=lambda e: e.id)
+
             self.assertEqual(errors, [invalid_base_form, invalid_edit_handler])
 
     @clear_edit_handler(ValidatedPage)