Improve status code comparison (#13006)

Fixes bug caused by override of BaseEnum.__new__ which broke comparison of status code values

src/backend/InvenTree/generic/states/states.py

@@ -9,6 +9,18 @@ from typing import Optional
 logger = logging.getLogger('inventree')
 
 
+def _new_int(cls, value):
+    """Construct a new int-based enum member with the provided value as its int payload.
+
+    Non-integer values (which are not valid status codes, and are ignored by
+    StatusCode._is_element) fall back to a zero payload.
+    """
+    if isinstance(value, int):
+        return int.__new__(cls, value)
+
+    return int.__new__(cls)
+
+
 class BaseEnum(enum.IntEnum):
     """An `Enum` capable of having its members have docstrings.
 
@@ -16,8 +28,13 @@ class BaseEnum(enum.IntEnum):
     """
 
     def __new__(cls, *args):
-        """Assign values on creation."""
-        obj = object.__new__(cls)
+        """Assign values on creation.
+
+        Note: The underlying int payload must be set (via int.__new__) to match the value,
+        otherwise any operation which uses the raw int (e.g. '!=', '<', bool(), json.dumps)
+        would see 0 for every member.
+        """
+        obj = _new_int(cls, args[0])
         obj._value_ = args[0]
         return obj
 
@@ -51,10 +68,13 @@ class BaseEnum(enum.IntEnum):
         return hash(self.value)
 
     def __ne__(self, obj):
-        """Override inequality operator to allow comparison with int."""
-        if type(self) is type(obj):
-            return super().__ne__(obj)
-        return self.value != obj
+        """Override inequality operator to remain consistent with __eq__."""
+        result = self.__eq__(obj)
+
+        if result is NotImplemented:
+            return result
+
+        return not result
 
 
 class StatusCode(BaseEnum):
@@ -72,7 +92,7 @@ class StatusCode(BaseEnum):
 
     def __new__(cls, *args):
         """Define object out of args."""
-        obj = int.__new__(cls)
+        obj = _new_int(cls, args[0])
         obj._value_ = args[0]
 
         # Normal item definition

src/backend/InvenTree/generic/states/tests.py

@@ -123,6 +123,41 @@ class GeneralStateTest(InvenTreeTestCase):
         # label
         self.assertEqual(GeneralStatus.label(10), 'Pending')
 
+    def test_int_payload(self):
+        """The underlying int payload of each member matches its value.
+
+        Regression test: members were previously constructed with a zero int payload,
+        so any operation using the raw int ('!=' between members of the same class,
+        ordering, bool(), arithmetic, json serialization) was silently wrong.
+        """
+        import json
+
+        from build.status_codes import BuildStatus
+
+        for cls in [GeneralStatus, BuildStatus]:
+            for member in cls.values():
+                self.assertEqual(int.__repr__(member), str(member.value))
+
+        pending, complete = GeneralStatus.PENDING, GeneralStatus.COMPLETE
+
+        # Comparison between members of the same class
+        self.assertNotEqual(pending, complete)
+        self.assertEqual(pending, GeneralStatus.PENDING)
+        self.assertNotEqual(BuildStatus.PENDING, BuildStatus.COMPLETE)
+        self.assertLess(pending, complete)
+        self.assertEqual(sorted([complete, pending]), [pending, complete])
+
+        # Comparison against raw integers
+        self.assertEqual(pending, 10)
+        self.assertNotEqual(pending, 20)
+        self.assertEqual(10, pending)
+        self.assertNotEqual(20, pending)
+
+        self.assertTrue(bool(pending))
+        self.assertEqual(pending + 1, 11)
+        self.assertEqual(f'{complete:d}', '30')
+        self.assertEqual(json.dumps({'status': complete}), '{"status": 30}')
+
     def test_color(self):
         """Test that the color enum validation works."""
         with self.assertRaises(ValueError) as e: