test failure modes

src/backend/InvenTree/InvenTree/test_serializers.py

@@ -91,3 +91,53 @@ class FilteredSerializers(InvenTreeAPITestCase):
             self.assertNotContains(response, 'field_b')
             self.assertNotContains(response, 'field_c')
             self.assertNotContains(response, 'field_d')
+
+    def test_failiure_enable_filter(self):
+        """Test sanity check for enable_filter."""
+        # Allowed usage
+        field_b = InvenTree.serializers.enable_filter(  # noqa: F841
+            InvenTree.serializers.FilterableSerializerMethodField(method_name='sample')
+        )
+
+        # Disallowed usage
+        with self.assertRaises(Exception) as cm:
+            field_a = InvenTree.serializers.enable_filter(  # noqa: F841
+                SerializerMethodField(method_name='sample')
+            )
+        self.assertIn(
+            'INVE-I2: `enable_filter` can only be applied to serializer fields',
+            str(cm.exception),
+        )
+
+    def test_failiure_FilterableSerializerMixin(self):
+        """Test failure case for FilteredSerializerMixin."""
+
+        class BadSerializer(
+            InvenTree.serializers.FilterableSerializerMixin,
+            InvenTree.serializers.InvenTreeModelSerializer,
+        ):
+            """Bad serializer for testing FilterableSerializerMixin."""
+
+            class Meta:
+                """Meta options."""
+
+                model = User
+                fields = ['field_a', 'id']
+
+            field_a = SerializerMethodField(method_name='sample')
+
+            def sample(self, obj):
+                """Sample method field."""
+                return 'sample'
+
+        with self.assertRaises(Exception) as cm:
+            _ = BadSerializer()
+        self.assertIn(
+            'INVE-I2: No filter targets found in fields, remove `PathScopedMixin`',
+            str(cm.exception),
+        )
+
+        # Test override
+        BadSerializer.no_filters = True
+        _ = BadSerializer()
+        self.assertTrue(True)  # Dummy assertion to ensure we reach here