From ed78d50103beb802cbf8471fcdf9e43c02760415 Mon Sep 17 00:00:00 2001
From: Christian Clauss <cclauss@me.com>
Date: Tue, 15 Apr 2025 22:31:55 +0200
Subject: [PATCH 1/2] Python lint: Ruff rules for pylint and code complexity

---
 pyproject.toml                              | 25 ++++++++++++++++---
 src/mcp/server/lowlevel/server.py           |  2 +-
 src/mcp/server/streamable_http.py           | 27 ++++++++++-----------
 tests/shared/test_progress_notifications.py |  2 +-
 4 files changed, 36 insertions(+), 20 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index 0a11a3b15..5c0a59562 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -91,18 +91,35 @@ venvPath = "."
 venv = ".venv"
 strict = ["src/mcp/**/*.py"]
 
-[tool.ruff.lint]
-select = ["C4", "E", "F", "I", "PERF", "UP"]
-ignore = ["PERF203"]
-
 [tool.ruff]
 line-length = 88
 target-version = "py310"
 
+[tool.ruff.lint]
+select = [
+    "C4",    # flake8-comprehensions
+    "C90",   # mccabe
+    "E",     # pycodestyle
+    "F",     # pyflakes
+    "I",     # isort
+    "PERF",  # Perflint
+    "PL",    # Pylint
+    "UP",    # pyupgrade
+]
+ignore = ["PERF203", "PLR0402"]
+mccabe.max-complexity = 24  # Default is 10
+
 [tool.ruff.lint.per-file-ignores]
 "__init__.py" = ["F401"]
 "tests/server/fastmcp/test_func_metadata.py" = ["E501"]
 
+[tool.ruff.lint.pylint]
+allow-magic-value-types = ["bytes", "float", "int", "str"]
+max-args = 20        # Default is 5
+max-branches = 23    # Default is 12
+max-returns = 13      # Default is 6
+max-statements = 99  # Default is 50
+
 [tool.uv.workspace]
 members = ["examples/servers/*"]
 
diff --git a/src/mcp/server/lowlevel/server.py b/src/mcp/server/lowlevel/server.py
index f6d390c2f..70491acc3 100644
--- a/src/mcp/server/lowlevel/server.py
+++ b/src/mcp/server/lowlevel/server.py
@@ -83,7 +83,7 @@ async def main():
 from mcp.server.lowlevel.helper_types import ReadResourceContents
 from mcp.server.models import InitializationOptions
 from mcp.server.session import ServerSession
-from mcp.server.stdio import stdio_server as stdio_server
+from mcp.server.stdio import stdio_server as stdio_server  # noqa: PLC0414
 from mcp.shared.context import RequestContext
 from mcp.shared.exceptions import McpError
 from mcp.shared.message import ServerMessageMetadata, SessionMessage
diff --git a/src/mcp/server/streamable_http.py b/src/mcp/server/streamable_http.py
index a94cc2834..b19357305 100644
--- a/src/mcp/server/streamable_http.py
+++ b/src/mcp/server/streamable_http.py
@@ -859,20 +859,19 @@ async def message_router():
                             if response_id in self._request_streams:
                                 target_request_id = response_id
 
-                        else:
-                            # Extract related_request_id from meta if it exists
-                            if (
-                                session_message.metadata is not None
-                                and isinstance(
-                                    session_message.metadata,
-                                    ServerMessageMetadata,
-                                )
-                                and session_message.metadata.related_request_id
-                                is not None
-                            ):
-                                target_request_id = str(
-                                    session_message.metadata.related_request_id
-                                )
+                        # Extract related_request_id from meta if it exists
+                        elif (
+                            session_message.metadata is not None
+                            and isinstance(
+                                session_message.metadata,
+                                ServerMessageMetadata,
+                            )
+                            and session_message.metadata.related_request_id
+                            is not None
+                        ):
+                            target_request_id = str(
+                                session_message.metadata.related_request_id
+                            )
 
                         request_stream_id = (
                             target_request_id
diff --git a/tests/shared/test_progress_notifications.py b/tests/shared/test_progress_notifications.py
index 1e0409e14..9f17caf20 100644
--- a/tests/shared/test_progress_notifications.py
+++ b/tests/shared/test_progress_notifications.py
@@ -41,7 +41,7 @@ async def run_server():
                 capabilities=server.get_capabilities(NotificationOptions(), {}),
             ),
         ) as server_session:
-            global serv_sesh
+            global serv_sesh  # noqa: PLW0603
 
             serv_sesh = server_session
             async for message in server_session.incoming_messages:

From 1596aca4ceb8ea52378ee273b9102e0c36ed24b6 Mon Sep 17 00:00:00 2001
From: Christian Clauss <cclauss@me.com>
Date: Tue, 3 Jun 2025 14:40:39 +0200
Subject: [PATCH 2/2] Increase max-statements to 102 (default is 50)

---
 pyproject.toml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index 5c0a59562..ec01b8d1b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -115,10 +115,10 @@ mccabe.max-complexity = 24  # Default is 10
 
 [tool.ruff.lint.pylint]
 allow-magic-value-types = ["bytes", "float", "int", "str"]
-max-args = 20        # Default is 5
-max-branches = 23    # Default is 12
+max-args = 20         # Default is 5
+max-branches = 23     # Default is 12
 max-returns = 13      # Default is 6
-max-statements = 99  # Default is 50
+max-statements = 102  # Default is 50
 
 [tool.uv.workspace]
 members = ["examples/servers/*"]