Tests: add a test for worlds to not modify the itempool after `create_items` (#1460)

* Tests: add a test for worlds to only modify the itempool in `create_items`

* extend test multiworld setup instead of a new function

* cleanup the test a bit

* put more strict wording in `create_items` docstring

* list of shame

* Don't call `set_rules` before testing

* remove ChecksFinder from the list of shame

---------

Co-authored-by: black-sliver <59490463+black-sliver@users.noreply.github.com>
Co-authored-by: Fabian Dill <Berserker66@users.noreply.github.com>

test/general/test_items.py

@@ -1,5 +1,6 @@
 import unittest
-from worlds.AutoWorld import AutoWorldRegister
+
+from worlds.AutoWorld import AutoWorldRegister, call_all
 from . import setup_solo_multiworld
 
 
@@ -53,7 +54,7 @@ class TestBase(unittest.TestCase):
                     f"{game_name} Item count MUST meet or exceed the number of locations",
                 )
 
-    def testItemsInDatapackage(self):
+    def test_items_in_datapackage(self):
         """Test that any created items in the itempool are in the datapackage"""
         for game_name, world_type in AutoWorldRegister.world_types.items():
             with self.subTest("Game", game=game_name):
@@ -69,3 +70,20 @@ class TestBase(unittest.TestCase):
                 with self.subTest("Name should be valid", game=game_name, item=name):
                     self.assertIn(name, valid_names,
                                   "All item descriptions must match defined item names")
+
+    def test_itempool_not_modified(self):
+        """Test that worlds don't modify the itempool after `create_items`"""
+        gen_steps = ("generate_early", "create_regions", "create_items")
+        additional_steps = ("set_rules", "generate_basic", "pre_fill")
+        excluded_games = ("Links Awakening DX", "Ocarina of Time", "SMZ3")
+        worlds_to_test = {game: world
+                          for game, world in AutoWorldRegister.world_types.items() if game not in excluded_games}
+        for game_name, world_type in worlds_to_test.items():
+            with self.subTest("Game", game=game_name):
+                multiworld = setup_solo_multiworld(world_type, gen_steps)
+                created_items = multiworld.itempool.copy()
+                for step in additional_steps:
+                    with self.subTest("step", step=step):
+                        call_all(multiworld, step)
+                        self.assertEqual(created_items, multiworld.itempool,
+                                         f"{game_name} modified the itempool during {step}")

worlds/AutoWorld.py

@@ -328,7 +328,7 @@ class World(metaclass=AutoWorldRegister):
 
     def create_items(self) -> None:
         """
-        Method for creating and submitting items to the itempool. Items and Regions should *not* be created and submitted
+        Method for creating and submitting items to the itempool. Items and Regions must *not* be created and submitted
         to the MultiWorld after this step. If items need to be placed during pre_fill use `get_prefill_items`.
         """
         pass