refactor: Make ServerCallContext a required parameter for RequestHandler methods (#782)

## Changes
- make `ServerCallContext` a required parameter for `RequestHandler`
methods
- update corresponding tests

## Note
I will make `ServerCallContext` a required parameter for the rest of the
Server in other PRs

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Fixes #718 🦕

Author: sokoliva

src/a2a/server/request_handlers/default_request_handler.py

@@ -123,7 +123,7 @@ def __init__(  # noqa: PLR0913
     async def on_get_task(
         self,
         params: GetTaskRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> Task | None:
         """Default handler for 'tasks/get'."""
         validate_history_length(params)
@@ -138,7 +138,7 @@ async def on_get_task(
     async def on_list_tasks(
         self,
         params: ListTasksRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> ListTasksResponse:
         """Default handler for 'tasks/list'."""
         validate_history_length(params)
@@ -159,7 +159,7 @@ async def on_list_tasks(
     async def on_cancel_task(
         self,
         params: CancelTaskRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> Task | None:
         """Default handler for 'tasks/cancel'.
 
@@ -231,7 +231,7 @@ async def _run_event_stream(
     async def _setup_message_execution(
         self,
         params: SendMessageRequest,
-        context: ServerCallContext | None,
+        context: ServerCallContext,
     ) -> tuple[TaskManager, str, EventQueue, ResultAggregator, asyncio.Task]:
         """Common setup logic for both streaming and non-streaming message handling.
 
@@ -322,7 +322,7 @@ async def _send_push_notification_if_needed(
     async def on_message_send(
         self,
         params: SendMessageRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> Message | Task:
         """Default handler for 'message/send' interface (non-streaming).
 
@@ -388,7 +388,7 @@ async def push_notification_callback(event: Event) -> None:
     async def on_message_send_stream(
         self,
         params: SendMessageRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> AsyncGenerator[Event]:
         """Default handler for 'message/stream' (streaming).
 
@@ -476,7 +476,7 @@ async def _cleanup_producer(
     async def on_create_task_push_notification_config(
         self,
         params: CreateTaskPushNotificationConfigRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> TaskPushNotificationConfig:
         """Default handler for 'tasks/pushNotificationConfig/create'.
 
@@ -504,7 +504,7 @@ async def on_create_task_push_notification_config(
     async def on_get_task_push_notification_config(
         self,
         params: GetTaskPushNotificationConfigRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> TaskPushNotificationConfig:
         """Default handler for 'tasks/pushNotificationConfig/get'.
 
@@ -538,7 +538,7 @@ async def on_get_task_push_notification_config(
     async def on_subscribe_to_task(
         self,
         params: SubscribeToTaskRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> AsyncGenerator[Event, None]:
         """Default handler for 'SubscribeToTask'.
 
@@ -580,7 +580,7 @@ async def on_subscribe_to_task(
     async def on_list_task_push_notification_configs(
         self,
         params: ListTaskPushNotificationConfigsRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> ListTaskPushNotificationConfigsResponse:
         """Default handler for 'ListTaskPushNotificationConfigs'.
 
@@ -611,7 +611,7 @@ async def on_list_task_push_notification_configs(
     async def on_delete_task_push_notification_config(
         self,
         params: DeleteTaskPushNotificationConfigRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> None:
         """Default handler for 'tasks/pushNotificationConfig/delete'.
 

src/a2a/server/request_handlers/jsonrpc_handler.py

@@ -141,7 +141,7 @@ def _get_request_id(
     async def on_message_send(
         self,
         request: SendMessageRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> dict[str, Any]:
         """Handles the 'message/send' JSON-RPC method.
 
@@ -174,7 +174,7 @@ async def on_message_send(
     async def on_message_send_stream(
         self,
         request: SendMessageRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> AsyncIterable[dict[str, Any]]:
         """Handles the 'message/stream' JSON-RPC method.
 
@@ -208,7 +208,7 @@ async def on_message_send_stream(
     async def on_cancel_task(
         self,
         request: CancelTaskRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> dict[str, Any]:
         """Handles the 'tasks/cancel' JSON-RPC method.
 
@@ -234,7 +234,7 @@ async def on_cancel_task(
     async def on_subscribe_to_task(
         self,
         request: SubscribeToTaskRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> AsyncIterable[dict[str, Any]]:
         """Handles the 'SubscribeToTask' JSON-RPC method.
 
@@ -268,7 +268,7 @@ async def on_subscribe_to_task(
     async def get_push_notification_config(
         self,
         request: GetTaskPushNotificationConfigRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> dict[str, Any]:
         """Handles the 'tasks/pushNotificationConfig/get' JSON-RPC method.
 
@@ -298,7 +298,7 @@ async def get_push_notification_config(
     async def set_push_notification_config(
         self,
         request: CreateTaskPushNotificationConfigRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> dict[str, Any]:
         """Handles the 'tasks/pushNotificationConfig/set' JSON-RPC method.
 
@@ -331,7 +331,7 @@ async def set_push_notification_config(
     async def on_get_task(
         self,
         request: GetTaskRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> dict[str, Any]:
         """Handles the 'tasks/get' JSON-RPC method.
 
@@ -357,7 +357,7 @@ async def on_get_task(
     async def list_tasks(
         self,
         request: ListTasksRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> dict[str, Any]:
         """Handles the 'tasks/list' JSON-RPC method.
 
@@ -381,7 +381,7 @@ async def list_tasks(
     async def list_push_notification_configs(
         self,
         request: ListTaskPushNotificationConfigsRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> dict[str, Any]:
         """Handles the 'ListTaskPushNotificationConfigs' JSON-RPC method.
 
@@ -406,7 +406,7 @@ async def list_push_notification_configs(
     async def delete_push_notification_config(
         self,
         request: DeleteTaskPushNotificationConfigRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> dict[str, Any]:
         """Handles the 'tasks/pushNotificationConfig/delete' JSON-RPC method.
 
@@ -429,7 +429,7 @@ async def delete_push_notification_config(
     async def get_authenticated_extended_card(
         self,
         request: GetExtendedAgentCardRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> dict[str, Any]:
         """Handles the 'agent/authenticatedExtendedCard' JSON-RPC method.
 

src/a2a/server/request_handlers/request_handler.py

@@ -33,7 +33,7 @@ class RequestHandler(ABC):
     async def on_get_task(
         self,
         params: GetTaskRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> Task | None:
         """Handles the 'tasks/get' method.
 
@@ -49,7 +49,7 @@ async def on_get_task(
 
     @abstractmethod
     async def on_list_tasks(
-        self, params: ListTasksRequest, context: ServerCallContext | None = None
+        self, params: ListTasksRequest, context: ServerCallContext
     ) -> ListTasksResponse:
         """Handles the tasks/list method.
 
@@ -68,7 +68,7 @@ async def on_list_tasks(
     async def on_cancel_task(
         self,
         params: CancelTaskRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> Task | None:
         """Handles the 'tasks/cancel' method.
 
@@ -86,7 +86,7 @@ async def on_cancel_task(
     async def on_message_send(
         self,
         params: SendMessageRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> Task | Message:
         """Handles the 'message/send' method (non-streaming).
 
@@ -105,7 +105,7 @@ async def on_message_send(
     async def on_message_send_stream(
         self,
         params: SendMessageRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> AsyncGenerator[Event]:
         """Handles the 'message/stream' method (streaming).
 
@@ -129,7 +129,7 @@ async def on_message_send_stream(
     async def on_create_task_push_notification_config(
         self,
         params: CreateTaskPushNotificationConfigRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> TaskPushNotificationConfig:
         """Handles the 'tasks/pushNotificationConfig/create' method.
 
@@ -147,7 +147,7 @@ async def on_create_task_push_notification_config(
     async def on_get_task_push_notification_config(
         self,
         params: GetTaskPushNotificationConfigRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> TaskPushNotificationConfig:
         """Handles the 'tasks/pushNotificationConfig/get' method.
 
@@ -165,7 +165,7 @@ async def on_get_task_push_notification_config(
     async def on_subscribe_to_task(
         self,
         params: SubscribeToTaskRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> AsyncGenerator[Event]:
         """Handles the 'SubscribeToTask' method.
 
@@ -188,7 +188,7 @@ async def on_subscribe_to_task(
     async def on_list_task_push_notification_configs(
         self,
         params: ListTaskPushNotificationConfigsRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> ListTaskPushNotificationConfigsResponse:
         """Handles the 'ListTaskPushNotificationConfigs' method.
 
@@ -206,7 +206,7 @@ async def on_list_task_push_notification_configs(
     async def on_delete_task_push_notification_config(
         self,
         params: DeleteTaskPushNotificationConfigRequest,
-        context: ServerCallContext | None = None,
+        context: ServerCallContext,
     ) -> None:
         """Handles the 'tasks/pushNotificationConfig/delete' method.