Add tests for StC tasks without client store

Author: LucaButBoring

src/mcp/client/session.py

@@ -762,7 +762,7 @@ async def _received_request(self, responder: RequestResponder[types.ServerReques
                             types.ErrorData(code=types.INVALID_REQUEST, message="Task store not configured")
                         )
 
-            case _:
+            case _:  # pragma: no cover
                 # Other request types are not expected to be received by the client
                 pass
 

tests/client/test_server_to_client_tasks.py

@@ -187,6 +187,42 @@ async def query_client_result(name: str, arguments: dict[str, Any]) -> list[type
         assert "EmptyResult" in result.content[0].text
 
 
+@pytest.mark.anyio
+async def test_server_queries_client_get_task_payload_without_task_store():
+    """Test server querying client for task payload without task store configured."""
+    server = Server("test", task_store=InMemoryTaskStore())
+
+    @server.list_tools()
+    async def list_tools() -> list[types.Tool]:
+        return [
+            types.Tool(
+                name="query_payload_no_store",
+                description="Query payload without store",
+                inputSchema={"type": "object", "properties": {}, "required": []},
+            )
+        ]
+
+    @server.call_tool()
+    async def query_payload_no_store(name: str, arguments: dict[str, Any]) -> list[types.TextContent]:
+        try:
+            session = server.request_context.session
+            await session.get_task_result("some-task", types.ClientResult)
+            return [types.TextContent(type="text", text="Should have failed")]
+        except Exception as e:
+            return [types.TextContent(type="text", text=f"Error: {str(e)}")]
+
+    async with create_connected_server_and_client_session(server) as client_session:
+        # No task store on client
+        await client_session.initialize()
+
+        result = await client_session.call_tool("query_payload_no_store", {})
+
+        assert len(result.content) == 1
+        assert isinstance(result.content[0], types.TextContent)
+        assert "Error" in result.content[0].text
+        assert "Task store not configured" in result.content[0].text or "INVALID_REQUEST" in result.content[0].text
+
+
 @pytest.mark.anyio
 async def test_server_queries_client_list_tasks():
     """Test server querying client's task list."""