fix: resolve pyright type errors in experimental.py and tests

- Fix Server type arg count in ExperimentalHandlers (1 param, not 2)
- Add proper type annotations to all test functions and parameters

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: BabyChrist666

src/mcp/server/lowlevel/experimental.py

@@ -54,7 +54,7 @@ class ExperimentalHandlers(Generic[LifespanResultT]):
 
     def __init__(
         self,
-        server: Server[LifespanResultT, Any],
+        server: Server[LifespanResultT],
     ) -> None:
         self._server = server
         self._task_support: TaskSupport | None = None

tests/server/lowlevel/test_handler_registration.py

@@ -1,33 +1,36 @@
 """Tests for public handler registration/deregistration API on low-level Server."""
 
+from typing import Any
+
 import pytest
 
+from mcp.server.context import ServerRequestContext
 from mcp.server.lowlevel.server import Server
 
 
 @pytest.fixture
-def server():
+def server() -> Server[None]:
     return Server(name="test-server")
 
 
-async def _dummy_request_handler(ctx, params):
+async def _dummy_request_handler(ctx: ServerRequestContext[None], params: Any) -> dict[str, str]:
     return {"result": "ok"}
 
 
-async def _dummy_notification_handler(ctx, params):
+async def _dummy_notification_handler(ctx: ServerRequestContext[None], params: Any) -> None:
     pass
 
 
 class TestAddRequestHandler:
-    def test_add_request_handler(self, server):
+    def test_add_request_handler(self, server: Server[None]) -> None:
         server.add_request_handler("custom/method", _dummy_request_handler)
         assert server.has_handler("custom/method")
 
-    def test_add_request_handler_replaces_existing(self, server):
-        async def handler_a(ctx, params):
+    def test_add_request_handler_replaces_existing(self, server: Server[None]) -> None:
+        async def handler_a(ctx: ServerRequestContext[None], params: Any) -> str:
             return "a"
 
-        async def handler_b(ctx, params):
+        async def handler_b(ctx: ServerRequestContext[None], params: Any) -> str:
             return "b"
 
         server.add_request_handler("custom/method", handler_a)
@@ -37,27 +40,27 @@ async def handler_b(ctx, params):
 
 
 class TestRemoveRequestHandler:
-    def test_remove_request_handler(self, server):
+    def test_remove_request_handler(self, server: Server[None]) -> None:
         server.add_request_handler("custom/method", _dummy_request_handler)
         assert server.has_handler("custom/method")
         server.remove_request_handler("custom/method")
         assert not server.has_handler("custom/method")
 
-    def test_remove_request_handler_not_found(self, server):
+    def test_remove_request_handler_not_found(self, server: Server[None]) -> None:
         with pytest.raises(KeyError):
             server.remove_request_handler("nonexistent/method")
 
 
 class TestAddNotificationHandler:
-    def test_add_notification_handler(self, server):
+    def test_add_notification_handler(self, server: Server[None]) -> None:
         server.add_notification_handler("custom/notify", _dummy_notification_handler)
         assert server.has_handler("custom/notify")
 
-    def test_add_notification_handler_replaces_existing(self, server):
-        async def handler_a(ctx, params):
+    def test_add_notification_handler_replaces_existing(self, server: Server[None]) -> None:
+        async def handler_a(ctx: ServerRequestContext[None], params: Any) -> None:
             pass
 
-        async def handler_b(ctx, params):
+        async def handler_b(ctx: ServerRequestContext[None], params: Any) -> None:
             pass
 
         server.add_notification_handler("custom/notify", handler_a)
@@ -66,29 +69,29 @@ async def handler_b(ctx, params):
 
 
 class TestRemoveNotificationHandler:
-    def test_remove_notification_handler(self, server):
+    def test_remove_notification_handler(self, server: Server[None]) -> None:
         server.add_notification_handler("custom/notify", _dummy_notification_handler)
         assert server.has_handler("custom/notify")
         server.remove_notification_handler("custom/notify")
         assert not server.has_handler("custom/notify")
 
-    def test_remove_notification_handler_not_found(self, server):
+    def test_remove_notification_handler_not_found(self, server: Server[None]) -> None:
         with pytest.raises(KeyError):
             server.remove_notification_handler("nonexistent/notify")
 
 
 class TestHasHandler:
-    def test_has_handler_request(self, server):
+    def test_has_handler_request(self, server: Server[None]) -> None:
         server.add_request_handler("custom/method", _dummy_request_handler)
         assert server.has_handler("custom/method")
 
-    def test_has_handler_notification(self, server):
+    def test_has_handler_notification(self, server: Server[None]) -> None:
         server.add_notification_handler("custom/notify", _dummy_notification_handler)
         assert server.has_handler("custom/notify")
 
-    def test_has_handler_unregistered(self, server):
+    def test_has_handler_unregistered(self, server: Server[None]) -> None:
         assert not server.has_handler("nonexistent/method")
 
-    def test_has_handler_default_ping(self, server):
+    def test_has_handler_default_ping(self, server: Server[None]) -> None:
         """The ping handler is registered by default."""
         assert server.has_handler("ping")