Fix start_activity() dropping priority parameter

temporalio/workflow.py

@@ -2087,6 +2087,7 @@ def start_activity(
         activity_id=activity_id,
         versioning_intent=versioning_intent,
         summary=summary,
+        priority=priority,
     )
 
 

tests/worker/test_interceptor.py

@@ -7,6 +7,7 @@
 
 from temporalio import activity, workflow
 from temporalio.client import Client, WorkflowUpdateFailedError
+from temporalio.common import Priority
 from temporalio.exceptions import ApplicationError
 from temporalio.testing import WorkflowEnvironment
 from temporalio.worker import (
@@ -324,3 +325,66 @@ async def test_workflow_instance_access_from_interceptor(client: Client):
             task_queue=task_queue,
         )
         assert difference == 0
+
+
+@activity.defn
+async def priority_activity() -> str:
+    return "done"
+
+
+captured_start_activity_inputs: List[StartActivityInput] = []
+
+
+class PriorityCapturingInterceptor(Interceptor):
+    def workflow_interceptor_class(
+        self, input: WorkflowInterceptorClassInput
+    ) -> Optional[Type[WorkflowInboundInterceptor]]:
+        return PriorityCapturingInboundInterceptor
+
+
+class PriorityCapturingInboundInterceptor(WorkflowInboundInterceptor):
+    def init(self, outbound: WorkflowOutboundInterceptor) -> None:
+        super().init(PriorityCapturingOutboundInterceptor(outbound))
+
+    async def execute_workflow(self, input: ExecuteWorkflowInput) -> Any:
+        return await super().execute_workflow(input)
+
+
+class PriorityCapturingOutboundInterceptor(WorkflowOutboundInterceptor):
+    def start_activity(self, input: StartActivityInput) -> workflow.ActivityHandle:
+        captured_start_activity_inputs.append(input)
+        return super().start_activity(input)
+
+
+@workflow.defn
+class StartActivityPriorityWorkflow:
+    @workflow.run
+    async def run(self) -> str:
+        # Use start_activity (not execute_activity) to test that path
+        handle = workflow.start_activity(
+            priority_activity,
+            start_to_close_timeout=timedelta(seconds=5),
+            priority=Priority(priority_key=3),
+        )
+        return await handle
+
+
+async def test_start_activity_forwards_priority(client: Client):
+    captured_start_activity_inputs.clear()
+    task_queue = f"task_queue_{uuid.uuid4()}"
+    async with Worker(
+        client,
+        task_queue=task_queue,
+        workflows=[StartActivityPriorityWorkflow],
+        activities=[priority_activity],
+        interceptors=[PriorityCapturingInterceptor()],
+    ):
+        result = await client.execute_workflow(
+            StartActivityPriorityWorkflow.run,
+            id=f"workflow_{uuid.uuid4()}",
+            task_queue=task_queue,
+        )
+        assert result == "done"
+
+    assert len(captured_start_activity_inputs) == 1
+    assert captured_start_activity_inputs[0].priority == Priority(priority_key=3)