fix: address review comments on test file and middleware

- Remove spurious `# noqa: F811` on __init__ (no redefinition here)
- Replace `bytes | None` with `Optional[bytes]` for Python 3.9 compat
- Use `asyncio.run()` instead of deprecated `get_event_loop().run_until_complete()`
- Remove unused `pytest` import

litellm/proxy/proxy_server.py

@@ -13409,7 +13409,7 @@ class _MCPTrailingSlashMiddleware:
     """Transparently append '/' to the MCP mount path so Starlette serves it
     directly instead of responding with 307 Temporary Redirect."""
 
-    def __init__(self, app: Any) -> None:  # noqa: F811
+    def __init__(self, app: Any) -> None:
         self.app = app
 
     async def __call__(self, scope: Any, receive: Any, send: Any) -> None:

tests/mcp_tests/test_mcp_trailing_slash_middleware.py

@@ -7,6 +7,7 @@ everything else through unchanged.
 """
 
 import asyncio
+from typing import Optional
 
 
 # The middleware is defined at module scope in proxy_server.py alongside heavy
@@ -45,17 +46,13 @@ class _Recorder:
         self.scopes.append(scope)
 
 
-def _make_http_scope(path: str, raw_path: bytes | None = None) -> dict:
+def _make_http_scope(path: str, raw_path: Optional[bytes] = None) -> dict:
     scope: dict = {"type": "http", "path": path}
     if raw_path is not None:
         scope["raw_path"] = raw_path
     return scope
 
 
-def _run(coro):
-    return asyncio.run(coro)
-
-
 # ── tests ────────────────────────────────────────────────────────────────
 
 
@@ -65,7 +62,7 @@ def test_rewrites_exact_mcp_path():
     mw = _MCPTrailingSlashMiddleware(recorder)
 
     scope = _make_http_scope("/mcp", b"/mcp")
-    _run(mw(scope, None, None))
+    asyncio.run(mw(scope, None, None))
 
     assert len(recorder.scopes) == 1
     assert recorder.scopes[0]["path"] == "/mcp/"
@@ -78,7 +75,7 @@ def test_no_rewrite_for_mcp_subpath():
     mw = _MCPTrailingSlashMiddleware(recorder)
 
     scope = _make_http_scope("/mcp/foo", b"/mcp/foo")
-    _run(mw(scope, None, None))
+    asyncio.run(mw(scope, None, None))
 
     assert recorder.scopes[0]["path"] == "/mcp/foo"
     assert recorder.scopes[0]["raw_path"] == b"/mcp/foo"
@@ -90,7 +87,7 @@ def test_no_rewrite_for_other_paths():
     mw = _MCPTrailingSlashMiddleware(recorder)
 
     scope = _make_http_scope("/health", b"/health")
-    _run(mw(scope, None, None))
+    asyncio.run(mw(scope, None, None))
 
     assert recorder.scopes[0]["path"] == "/health"
 
@@ -101,7 +98,7 @@ def test_no_rewrite_for_non_http_scope():
     mw = _MCPTrailingSlashMiddleware(recorder)
 
     scope = {"type": "websocket", "path": "/mcp"}
-    _run(mw(scope, None, None))
+    asyncio.run(mw(scope, None, None))
 
     assert recorder.scopes[0]["path"] == "/mcp"
 
@@ -112,7 +109,7 @@ def test_raw_path_fallback_when_absent():
     mw = _MCPTrailingSlashMiddleware(recorder)
 
     scope = _make_http_scope("/mcp")  # no raw_path
-    _run(mw(scope, None, None))
+    asyncio.run(mw(scope, None, None))
 
     assert recorder.scopes[0]["path"] == "/mcp/"
     assert recorder.scopes[0]["raw_path"] == b"/mcp/"
@@ -124,7 +121,7 @@ def test_already_trailing_slash_no_double():
     mw = _MCPTrailingSlashMiddleware(recorder)
 
     scope = _make_http_scope("/mcp/", b"/mcp/")
-    _run(mw(scope, None, None))
+    asyncio.run(mw(scope, None, None))
 
     assert recorder.scopes[0]["path"] == "/mcp/"
     assert recorder.scopes[0]["raw_path"] == b"/mcp/"