Core: optimize early items and add unit test (#1197)

* optimize early items and add unit test

* move sorting list init closer to sorting

test/general/TestFill.py

@@ -1,7 +1,8 @@
 from typing import List, Iterable
 import unittest
 from worlds.AutoWorld import World
-from Fill import FillError, balance_multiworld_progression, fill_restrictive, distribute_items_restrictive
+from Fill import FillError, balance_multiworld_progression, fill_restrictive, \
+    distribute_early_items, distribute_items_restrictive
 from BaseClasses import Entrance, LocationProgressType, MultiWorld, Region, RegionType, Item, Location, \
     ItemClassification
 from worlds.generic.Rules import CollectionRule, add_item_rule, locality_rules, set_rule
@@ -13,7 +14,7 @@ def generate_multi_world(players: int = 1) -> MultiWorld:
     for i in range(players):
         player_id = i+1
         world = World(multi_world, player_id)
-        multi_world.game[player_id] = world
+        multi_world.game[player_id] = f"Game {player_id}"
         multi_world.worlds[player_id] = world
         multi_world.player_name[player_id] = "Test Player " + str(player_id)
         region = Region("Menu", RegionType.Generic,
@@ -623,6 +624,55 @@ class TestDistributeItemsRestrictive(unittest.TestCase):
             self.assertEqual(item.player, item.location.player)
             self.assertFalse(item.location.event, False)
 
+    def test_early_items(self) -> None:
+        mw = generate_multi_world(2)
+        player1 = generate_player_data(mw, 1, location_count=5, basic_item_count=5)
+        player2 = generate_player_data(mw, 2, location_count=5, basic_item_count=5)
+        mw.early_items[1].value[player1.basic_items[0].name] = 1
+        mw.early_items[2].value[player2.basic_items[2].name] = 1
+        mw.early_items[2].value[player2.basic_items[3].name] = 1
+
+        early_items = [
+            player1.basic_items[0],
+            player2.basic_items[2],
+            player2.basic_items[3],
+        ]
+
+        # copied this code from the beginning of `distribute_items_restrictive`
+        # before `distribute_early_items` is called
+        fill_locations = sorted(mw.get_unfilled_locations())
+        mw.random.shuffle(fill_locations)
+        itempool = sorted(mw.itempool)
+        mw.random.shuffle(itempool)
+
+        fill_locations, itempool = distribute_early_items(mw, fill_locations, itempool)
+
+        remaining_p1 = [item for item in itempool if item.player == 1]
+        remaining_p2 = [item for item in itempool if item.player == 2]
+
+        assert len(itempool) == 7, f"number of items remaining after early_items: {len(itempool)}"
+        assert len(remaining_p1) == 4, f"number of p1 items after early_items: {len(remaining_p1)}"
+        assert len(remaining_p2) == 3, f"number of p2 items after early_items: {len(remaining_p1)}"
+        for i in range(5):
+            if i != 0:
+                assert player1.basic_items[i] in itempool, "non-early item to remain in itempool"
+            if i not in {2, 3}:
+                assert player2.basic_items[i] in itempool, "non-early item to remain in itempool"
+        for item in early_items:
+            assert item not in itempool, "early item to be taken out of itempool"
+
+        assert len(fill_locations) == len(mw.get_locations()) - len(early_items), \
+            f"early location count from {mw.get_locations()} to {len(fill_locations)} " \
+            f"after {len(early_items)} early items"
+
+        items_in_locations = {loc.item for loc in mw.get_locations() if loc.item}
+
+        assert len(items_in_locations) == len(early_items), \
+            f"{len(early_items)} early items in {len(items_in_locations)} locations"
+
+        for item in early_items:
+            assert item in items_in_locations, "early item to be placed in location"
+
 
 class TestBalanceMultiworldProgression(unittest.TestCase):
     def assertRegionContains(self, region: Region, item: Item) -> bool: