Allow automatic transition to None - add test for automatic transition

dlgr/griduniverse/experiment.py

@@ -837,27 +837,29 @@ def items_changed(self, last_items):
                 return True
         return False
 
-    def trigger_transitions(self):
-        now = time.time()
+    def trigger_transitions(self, time=time.time):
+        now = time()
         to_change = []
         for position, item in self.item_locations.items():
             item_type = self.item_config.get(item.item_id)
             if not item_type:
                 continue
             if "auto_transition_time" in item_type:
                 if now - item.creation_timestamp >= item_type["auto_transition_time"]:
-                    new_target_item = Item(
+                    target = item_type.get("auto_transition_target")
+                    new_target_item = target and Item(
                         id=item.id,
                         position=position,
-                        item_config=self.item_config[
-                            item_type["auto_transition_target"]
-                        ],
+                        item_config=self.item_config[target],
                     )
                     to_change.append((position, new_target_item))
         if to_change:
             self.items_updated = True
         for position, new_target_item in to_change:
-            self.item_locations[position] = new_target_item
+            if new_target_item is None:
+                del self.item_locations[position]
+            else:
+                self.item_locations[position] = new_target_item
 
     def replenish_items(self):
         items_by_type = collections.defaultdict(list)

test/test_automatic_transitions.py

@@ -0,0 +1,57 @@
+import time
+
+import pytest
+
+
+class TestAutoTransition(object):
+    messages = []
+
+    def test_automatic_transition(self, exp):
+        from dlgr.griduniverse.experiment import Item
+
+        item = Item(
+            {
+                "id": 1,
+                "item_id": "sunflower_sprout",
+                "name": "Sunflower Sprout",
+                "n_uses": 1,
+            }
+        )
+        exp.grid.item_locations[(2, 2)] = item
+
+        exp.grid.trigger_transitions(time=lambda: time.time() + 5)
+        assert exp.grid.item_locations[(2, 2)].item_id == "sunflower_bud"
+
+    def test_null_target(self, exp):
+        from dlgr.griduniverse.experiment import Item
+
+        item = Item(
+            {
+                "id": 1,
+                "item_id": "sunflower_dried",
+                "name": "Sunflower Dried",
+                "n_uses": 1,
+            }
+        )
+        exp.grid.item_locations[(2, 2)] = item
+
+        exp.item_config["sunflower_sprout"]["auto_transition_target"] = None
+        exp.grid.trigger_transitions(time=lambda: time.time() + 5)
+        assert (2, 2) not in exp.grid.item_locations
+
+
+@pytest.fixture(autouse=True)
+def add_item_config(exp):
+    """Make sure item configs needed for these tests are set"""
+    exp.grid.item_config["sunflower_dried"] = {
+        "name": "Sunflower dried",
+        "item_id": "sunflower_dried",
+        "n_uses": 1,
+        "auto_transition_time": 5,
+    }
+    exp.grid.item_config["sunflower_sprout"] = {
+        "auto_transition_target": "sunflower_bud",
+        "auto_transition_time": 5,
+        "n_uses": 1,
+        "name": "Sunflower sprout",
+    }