Speed up group setup (#38048)

homeassistant/components/group/__init__.py

@@ -39,6 +39,7 @@ from homeassistant.loader import bind_hass
 # mypy: allow-untyped-calls, allow-untyped-defs, no-check-untyped-defs
 
 DOMAIN = "group"
+GROUP_ORDER = "group_order"
 
 ENTITY_ID_FORMAT = DOMAIN + ".{}"
 
@@ -407,16 +408,23 @@ class Group(Entity):
 
         This method must be run in the event loop.
         """
+        hass.data.setdefault(GROUP_ORDER, 0)
+
         group = Group(
             hass,
             name,
-            order=len(hass.states.async_entity_ids(DOMAIN)),
+            order=hass.data[GROUP_ORDER],
             icon=icon,
             user_defined=user_defined,
             entity_ids=entity_ids,
             mode=mode,
         )
 
+        # Keep track of the group order without iterating
+        # every state in the state machine every time
+        # we setup a new group
+        hass.data[GROUP_ORDER] += 1
+
         group.entity_id = async_generate_entity_id(
             ENTITY_ID_FORMAT, object_id or name, hass=hass
         )

tests/components/group/test_init.py

@@ -490,3 +490,25 @@ async def test_service_group_set_group_remove_group(hass):
 
     group_state = hass.states.get("group.user_test_group")
     assert group_state is None
+
+
+async def test_group_order(hass):
+    """Test that order gets incremented when creating a new group."""
+    hass.states.async_set("light.bowl", STATE_ON)
+
+    assert await async_setup_component(
+        hass,
+        "group",
+        {
+            "group": {
+                "group_zero": {"entities": "light.Bowl", "icon": "mdi:work"},
+                "group_one": {"entities": "light.Bowl", "icon": "mdi:work"},
+                "group_two": {"entities": "light.Bowl", "icon": "mdi:work"},
+            }
+        },
+    )
+    await hass.async_block_till_done()
+
+    assert hass.states.get("group.group_zero").attributes["order"] == 0
+    assert hass.states.get("group.group_one").attributes["order"] == 1
+    assert hass.states.get("group.group_two").attributes["order"] == 2