WIP: cancellation

Author: dandavison

temporalio/worker/_workflow_instance.py

@@ -422,8 +422,6 @@ def activate(
                 continue
             i += 1
 
-        if seen_completion:
-            self._warn_if_unfinished_handlers()
         return self._current_completion
 
     def _apply(

tests/worker/test_workflow.py

@@ -5632,6 +5632,53 @@ async def finish(self):
         self.workflow_may_exit = True
 
 
+@workflow.defn
+class UpdateCancellationWorkflow(CoroutinesUseLockWorkflow):
+    def __init__(self) -> None:
+        self.non_terminating_operation_has_started = False
+
+    @workflow.run
+    async def run(self) -> str:
+        await workflow.wait_condition(lambda: False)
+        return "unreachable"
+
+    @workflow.update
+    async def wait_until_non_terminating_operation_has_started(self) -> None:
+        await workflow.wait_condition(
+            lambda: self.non_terminating_operation_has_started
+        )
+
+    @workflow.update
+    async def non_terminating_operation(self) -> str:
+        self.non_terminating_operation_has_started = True
+        await workflow.wait_condition(lambda: False)
+        return "unreachable"
+
+
+async def test_update_cancellation(client: Client):
+    async with new_worker(client, UpdateCancellationWorkflow) as worker:
+        wf_handle = await client.start_workflow(
+            UpdateCancellationWorkflow.run,
+            id=str(uuid.uuid4()),
+            task_queue=worker.task_queue,
+        )
+        # Asynchronously run an update that will never complete
+        non_terminating_update_task = asyncio.create_task(
+            wf_handle.execute_update(
+                UpdateCancellationWorkflow.non_terminating_operation
+            )
+        )
+        print("wait until handler started...")
+        # Wait until we know the update handler has started executing
+        await wf_handle.execute_update(
+            UpdateCancellationWorkflow.wait_until_non_terminating_operation_has_started
+        )
+        print("cancel the workflow")
+        await wf_handle.cancel()
+        print("await non_terminating_update_task...")
+        await non_terminating_update_task
+
+
 async def _do_workflow_coroutines_lock_or_semaphore_test(
     client: Client,
     params: UseLockOrSemaphoreWorkflowParameters,