Tests: test that item/location name groups are not empty (#2748)

* Tests: test that item/location name groups are not empty

* Tests: better name for test_groups TestCase

---------

Co-authored-by: Fabian Dill <Berserker66@users.noreply.github.com>

test/general/test_groups.py

@@ -0,0 +1,27 @@
+from unittest import TestCase
+
+from worlds.AutoWorld import AutoWorldRegister
+
+
+class TestNameGroups(TestCase):
+    def test_item_name_groups_not_empty(self) -> None:
+        """
+        Test that there are no empty item name groups, which is likely a bug.
+        """
+        for game_name, world_type in AutoWorldRegister.world_types.items():
+            if not world_type.item_id_to_name:
+                continue  # ignore worlds without items
+            with self.subTest(game=game_name):
+                for name, group in world_type.item_name_groups.items():
+                    self.assertTrue(group, f"Item name group \"{name}\" of \"{game_name}\" is empty")
+
+    def test_location_name_groups_not_empty(self) -> None:
+        """
+        Test that there are no empty location name groups, which is likely a bug.
+        """
+        for game_name, world_type in AutoWorldRegister.world_types.items():
+            if not world_type.location_id_to_name:
+                continue  # ignore worlds without locations
+            with self.subTest(game=game_name):
+                for name, group in world_type.location_name_groups.items():
+                    self.assertTrue(group, f"Location name group \"{name}\" of \"{game_name}\" is empty")