only combine items on the sink addon

overcooked_simulator/counters.py

@@ -362,7 +362,7 @@ class SinkAddon(Counter):
         self.occupied_by = deque(occupied_by) if occupied_by else deque()
 
     def can_drop_off(self, item: Item) -> bool:
-        return not self.occupied_by or self.occupied_by[-1].can_combine(item)
+        return self.occupied_by and self.occupied_by[-1].can_combine(item)
 
     def drop_off(self, item: Item) -> Item | None:
         """Takes the thing dropped of by the player.
@@ -370,14 +370,10 @@ class SinkAddon(Counter):
         Args:
             item: The item to be placed on the counter.
 
-        Returns: TODO Return information, whether the score is affected (Serving Window?)
+        Returns:
 
         """
-        if not self.occupied_by:
-            self.occupied_by.append(item)
-        elif self.occupied_by[-1].can_combine(item):
-            return self.occupied_by[-1].combine(item)
-        return None
+        return self.occupied_by[-1].combine(item)
 
     def add_clean_plate(self, plate: Plate):
         self.occupied_by.appendleft(plate)

overcooked_simulator/game_content/layouts/basic.layout

@@ -4,8 +4,8 @@ _#_______M_______
 _#_______#_______
 _W_______________
 _#__A__A_________
-_B_______________
-_B_______#_______
+_C_______________
+_C_______#_______
 _#_______X_______
 _#P#S+#S+#_______
 _________________