Cancel update tasks on workflow cancellation

Author: dandavison

temporalio/worker/_workflow_instance.py

@@ -1851,6 +1851,13 @@ async def _run_top_level_workflow_function(self, coro: Awaitable[None]) -> None:
                 err
             ):
                 self._add_command().cancel_workflow_execution.SetInParent()
+                # Cancel update tasks, so that the update caller receives an
+                # update failed error. We do not currently cancel signal tasks
+                # since (a) doing so would require a workflow flag and (b) the
+                # presence of the update caller gives a strong reason to cancel
+                # update tasks.
+                for update_handler in self._in_progress_updates.values():
+                    update_handler.task.cancel("The workflow was cancelled.")
             elif self._is_workflow_failure_exception(err):
                 # All other failure errors fail the workflow
                 self._set_workflow_failure(err)

tests/worker/test_workflow.py

@@ -5646,7 +5646,16 @@ async def _run_workflow_and_get_warning(self) -> bool:
             with pytest.WarningsRecorder() as warnings:
                 if self.handler_type == "-update-":
                     assert update_task
-                    if self.handler_waiting == "-wait-all-handlers-finish-":
+
+                    if self.workflow_termination_type == "-cancellation-":
+                        with pytest.raises(WorkflowUpdateFailedError) as update_err:
+                            await update_task
+                        assert isinstance(update_err.value.cause, CancelledError)
+                        assert (
+                            "the workflow was cancelled"
+                            in str(update_err.value.cause).lower()
+                        )
+                    elif self.handler_waiting == "-wait-all-handlers-finish-":
                         await update_task
                     else:
                         with pytest.raises(RPCError) as update_err: