Fix unit test (#6084)

* Add debug print statements

* Add more debug prints

* Upate unit test

- Use global variables to ensure correct error is raised
- collect() does not always collect in the same "order"

InvenTree/InvenTree/helpers.py

@@ -832,6 +832,7 @@ def inheritors(cls):
     """Return all classes that are subclasses from the supplied cls."""
     subcls = set()
     work = [cls]
+
     while work:
         parent = work.pop()
         for child in parent.__subclasses__():

InvenTree/generic/states/test_transition.py

@@ -4,6 +4,13 @@ from InvenTree.unit_test import InvenTreeTestCase
 
 from .transition import StateTransitionMixin, TransitionMethod, storage
 
+# Global variables to determine which transition classes raises an exception
+global raise_storage
+global raise_function
+
+raise_storage = False
+raise_function = False
+
 
 class MyPrivateError(NotImplementedError):
     """Error for testing purposes."""
@@ -16,6 +23,7 @@ def dflt(*args, **kwargs):
 
 def _clean_storage(refs):
     """Clean the storage."""
+
     for ref in refs:
         del ref
     storage.collect()
@@ -38,9 +46,20 @@ class TransitionTests(InvenTreeTestCase):
     def test_storage(self):
         """Ensure that the storage collection mechanism works."""
 
+        global raise_storage
+        global raise_function
+
+        raise_storage = True
+        raise_function = False
+
         class RaisingImplementation(TransitionMethod):
             def transition(self, *args, **kwargs):
-                raise MyPrivateError('RaisingImplementation')
+                """Custom transition method."""
+
+                global raise_storage
+
+                if raise_storage:
+                    raise MyPrivateError('RaisingImplementation')
 
         # Ensure registering works
         storage.collect()
@@ -58,6 +77,12 @@ class TransitionTests(InvenTreeTestCase):
     def test_function(self):
         """Ensure that a TransitionMethod's function is called."""
 
+        global raise_storage
+        global raise_function
+
+        raise_storage = False
+        raise_function = True
+
         # Setup
         class ValidImplementationNoEffect(TransitionMethod):
             def transition(self, *args, **kwargs):

InvenTree/generic/states/transition.py

@@ -71,6 +71,7 @@ class StateTransitionMixin:
             instance: Object instance
             default_action: Default action to be taken if none of the transitions returns a boolean true value
         """
+
         # Check if there is a custom override function for this transition
         for override in storage.list:
             rslt = override.transition(current_state, target_state, instance, default_action, **kwargs)