Fix scheduler race conditions and add comprehensive test suite (#9348)

tests/integration/test_scheduler_defer_cancel.py

@@ -0,0 +1,94 @@
+"""Test that defer() with the same name cancels previous defers."""
+
+import asyncio
+
+from aioesphomeapi import EntityState, Event, EventInfo, UserService
+import pytest
+
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@pytest.mark.asyncio
+async def test_scheduler_defer_cancel(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """Test that defer() with the same name cancels previous defers."""
+
+    async with run_compiled(yaml_config), api_client_connected() as client:
+        # Verify we can connect
+        device_info = await client.device_info()
+        assert device_info is not None
+        assert device_info.name == "scheduler-defer-cancel"
+
+        # List entities and services
+        entity_info, services = await asyncio.wait_for(
+            client.list_entities_services(), timeout=5.0
+        )
+
+        # Find our test entities
+        test_complete_entity: EventInfo | None = None
+        test_result_entity: EventInfo | None = None
+
+        for entity in entity_info:
+            if isinstance(entity, EventInfo):
+                if entity.object_id == "test_complete":
+                    test_complete_entity = entity
+                elif entity.object_id == "test_result":
+                    test_result_entity = entity
+
+        assert test_complete_entity is not None, "test_complete event not found"
+        assert test_result_entity is not None, "test_result event not found"
+
+        # Find our test service
+        test_defer_cancel_service: UserService | None = None
+        for service in services:
+            if service.name == "test_defer_cancel":
+                test_defer_cancel_service = service
+
+        assert test_defer_cancel_service is not None, (
+            "test_defer_cancel service not found"
+        )
+
+        # Get the event loop
+        loop = asyncio.get_running_loop()
+
+        # Subscribe to states
+        test_complete_future: asyncio.Future[bool] = loop.create_future()
+        test_result_future: asyncio.Future[int] = loop.create_future()
+
+        def on_state(state: EntityState) -> None:
+            if not isinstance(state, Event):
+                return
+
+            if (
+                state.key == test_complete_entity.key
+                and state.event_type == "test_finished"
+                and not test_complete_future.done()
+            ):
+                test_complete_future.set_result(True)
+                return
+
+            if state.key == test_result_entity.key and not test_result_future.done():
+                # Event type should be "defer_executed_X" where X is the defer number
+                if state.event_type.startswith("defer_executed_"):
+                    defer_num = int(state.event_type.split("_")[-1])
+                    test_result_future.set_result(defer_num)
+
+        client.subscribe_states(on_state)
+
+        # Execute the test
+        client.execute_service(test_defer_cancel_service, {})
+
+        # Wait for test completion
+        try:
+            await asyncio.wait_for(test_complete_future, timeout=10.0)
+            executed_defer = await asyncio.wait_for(test_result_future, timeout=1.0)
+        except asyncio.TimeoutError:
+            pytest.fail("Test did not complete within timeout")
+
+        # Verify that only defer 10 was executed
+        assert executed_defer == 10, (
+            f"Expected defer 10 to execute, got {executed_defer}"
+        )