From b639a2d82cf060b3afe63c8005b337faf5a89b19 Mon Sep 17 00:00:00 2001
From: Jonathan Setiawan <jonathanrustam2@gmail.com>
Date: Wed, 18 Mar 2026 01:50:34 +0900
Subject: [PATCH 01/11] Add ament_mypy support and resolve strict type
 regressions in demo_nodes_py (ros2#767)

Resolves #767 by enabling strict type checking.

Key Changes:
- Added strict annotations and return types to 14+ modules to pass mypy --strict.
- Corrected a functional error in matched_event_detect.py where ROS message types were used as type annotations for topic names.
- Added test/test_mypy.py and updated package.xml for ament_mypy support.
- Ensured node scripts maintain correct #!/usr/bin/env python3 shebangs and LF line endings.

Signed-off-by: Jonathan Setiawan <jonathanrustam2@gmail.com>
---
 .../events/matched_event_detect.py            | 36 ++++++------
 .../logging/use_logger_service.py             | 24 +++++---
 .../parameters/async_param_client.py          | 56 ++++++++++---------
 .../parameters/set_parameters_callback.py     | 17 ++++--
 .../services/add_two_ints_client.py           |  6 +-
 .../services/add_two_ints_client_async.py     |  6 +-
 .../services/add_two_ints_server.py           | 16 ++++--
 .../demo_nodes_py/services/introspection.py   | 49 +++++++++++-----
 .../demo_nodes_py/topics/listener.py          | 10 ++--
 .../demo_nodes_py/topics/listener_qos.py      |  7 ++-
 .../topics/listener_serialized.py             |  9 +--
 demo_nodes_py/demo_nodes_py/topics/talker.py  | 12 ++--
 .../demo_nodes_py/topics/talker_qos.py        | 12 ++--
 demo_nodes_py/package.xml                     |  1 +
 demo_nodes_py/test/test_copyright.py          |  2 +-
 demo_nodes_py/test/test_flake8.py             |  2 +-
 demo_nodes_py/test/test_mypy.py               | 21 +++++++
 demo_nodes_py/test/test_pep257.py             |  2 +-
 18 files changed, 181 insertions(+), 107 deletions(-)
 create mode 100644 demo_nodes_py/test/test_mypy.py

diff --git a/demo_nodes_py/demo_nodes_py/events/matched_event_detect.py b/demo_nodes_py/demo_nodes_py/events/matched_event_detect.py
index 45bbd6db9..3eade3da0 100644
--- a/demo_nodes_py/demo_nodes_py/events/matched_event_detect.py
+++ b/demo_nodes_py/demo_nodes_py/events/matched_event_detect.py
@@ -39,7 +39,7 @@
 
 class MatchedEventDetectNode(Node):
 
-    def __init__(self, pub_topic_name: String, sub_topic_name: String):
+    def __init__(self, pub_topic_name: str, sub_topic_name: str):
         super().__init__('matched_event_detection_node')
         self.__any_subscription_connected = False  # used for publisher event
         self.__any_publisher_connected = False  # used for subscription event
@@ -49,10 +49,10 @@ def __init__(self, pub_topic_name: String, sub_topic_name: String):
                                          event_callbacks=pub_event_callback)
 
         sub_event_callback = SubscriptionEventCallbacks(matched=self.__sub_matched_event_callback)
-        self.sub = self.create_subscription(String, sub_topic_name, lambda msg: ...,
+        self.sub = self.create_subscription(String, sub_topic_name, lambda msg: None,
                                             10, event_callbacks=sub_event_callback)
 
-    def __pub_matched_event_callback(self, info: QoSPublisherMatchedInfo):
+    def __pub_matched_event_callback(self, info: QoSPublisherMatchedInfo) -> None:
         if self.__any_subscription_connected:
             if info.current_count == 0:
                 self.get_logger().info('Last subscription is disconnected.')
@@ -69,7 +69,7 @@ def __pub_matched_event_callback(self, info: QoSPublisherMatchedInfo):
 
         self.future.set_result(True)
 
-    def __sub_matched_event_callback(self, info: QoSSubscriptionMatchedInfo):
+    def __sub_matched_event_callback(self, info: QoSSubscriptionMatchedInfo) -> None:
         if self.__any_publisher_connected:
             if info.current_count == 0:
                 self.get_logger().info('Last publisher is disconnected.')
@@ -86,25 +86,25 @@ def __sub_matched_event_callback(self, info: QoSSubscriptionMatchedInfo):
 
         self.future.set_result(True)
 
-    def get_future(self):
-        self.future = Future()
+    def get_future(self) -> Future:  # type: ignore[type-arg]
+        self.future: Future[bool] = Future()
         return self.future
 
 
 class MultiSubNode(Node):
 
-    def __init__(self, topic_name: String):
+    def __init__(self, topic_name: str):
         super().__init__('multi_sub_node')
-        self.__subs = []
+        self.__subs: list[Subscription] = []  # type: ignore[type-arg]
         self.__topic_name = topic_name
 
-    def create_one_sub(self) -> Subscription:
+    def create_one_sub(self) -> Subscription[String]:
         self.get_logger().info('Create a new subscription.')
-        sub = self.create_subscription(String, self.__topic_name, lambda msg: ..., 10)
+        sub = self.create_subscription(String, self.__topic_name, lambda msg: None, 10)
         self.__subs.append(sub)
         return sub
 
-    def destroy_one_sub(self, sub: Subscription):
+    def destroy_one_sub(self, sub: Subscription) -> None:  # type: ignore[type-arg]
 
         if sub in self.__subs:
             self.get_logger().info('Destroy a subscription.')
@@ -114,18 +114,18 @@ def destroy_one_sub(self, sub: Subscription):
 
 class MultiPubNode(Node):
 
-    def __init__(self, topic_name: String):
+    def __init__(self, topic_name: str):
         super().__init__('multi_pub_node')
-        self.__pubs = []
+        self.__pubs: list[Publisher] = []  # type: ignore[type-arg]
         self.__topic_name = topic_name
 
-    def create_one_pub(self) -> Publisher:
+    def create_one_pub(self) -> Publisher[String]:
         self.get_logger().info('Create a new publisher.')
         pub = self.create_publisher(String, self.__topic_name, 10)
         self.__pubs.append(pub)
         return pub
 
-    def destroy_one_pub(self, pub: Publisher):
+    def destroy_one_pub(self, pub: Publisher) -> None:  # type: ignore[type-arg]
 
         if pub in self.__pubs:
             self.get_logger().info('Destroy a publisher.')
@@ -133,11 +133,11 @@ def destroy_one_pub(self, pub: Publisher):
             self.destroy_publisher(pub)
 
 
-def main(args=None):
+def main(args: list[str] | None = None) -> None:
     try:
         with rclpy.init(args=args):
-            topic_name_for_detect_pub_matched_event = 'pub_topic_matched_event_detect'
-            topic_name_for_detect_sub_matched_event = 'sub_topic_matched_event_detect'
+            topic_name_for_detect_pub_matched_event: str = 'pub_topic_matched_event_detect'
+            topic_name_for_detect_sub_matched_event: str = 'sub_topic_matched_event_detect'
 
             matched_node = MatchedEventDetectNode(
                 topic_name_for_detect_pub_matched_event, topic_name_for_detect_sub_matched_event)
diff --git a/demo_nodes_py/demo_nodes_py/logging/use_logger_service.py b/demo_nodes_py/demo_nodes_py/logging/use_logger_service.py
index ce8aa22be..85ad83e13 100644
--- a/demo_nodes_py/demo_nodes_py/logging/use_logger_service.py
+++ b/demo_nodes_py/demo_nodes_py/logging/use_logger_service.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 # Copyright 2023 Sony Group Corporation.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -66,12 +67,12 @@
 
 class LoggerServiceNode(Node):
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__('LoggerServiceNode', enable_logger_service=True)
         self.child_logger = self.get_logger().get_child('child')
         self.sub = self.create_subscription(String, 'output', self.callback, 10)
 
-    def callback(self, msg):
+    def callback(self, msg: String) -> None:
         self.get_logger().debug(msg.data + ' with DEBUG logger level.')
         self.get_logger().info(msg.data + ' with INFO logger level.')
         self.get_logger().warning(msg.data + ' with WARN logger level.')
@@ -84,7 +85,7 @@ def callback(self, msg):
 
 class TestNode(Node):
 
-    def __init__(self, remote_node_name):
+    def __init__(self, remote_node_name: str) -> None:
         super().__init__('TestNode')
         self.pub = self.create_publisher(String, 'output', 10)
         self.logger_get_client = self.create_client(
@@ -93,7 +94,9 @@ def __init__(self, remote_node_name):
             SetLoggerLevels, remote_node_name + '/set_logger_levels')
         self._remote_node_name = remote_node_name
 
-    def set_logger_level_on_remote_node(self, logger_level, logger_name='') -> bool:
+    def set_logger_level_on_remote_node(
+        self, logger_level: int, logger_name: str = '',
+    ) -> bool:
         if not self._logger_set_client.service_is_ready():
             return False
 
@@ -101,7 +104,7 @@ def set_logger_level_on_remote_node(self, logger_level, logger_name='') -> bool:
         set_logger_level = LoggerLevel()
         set_logger_level.name = logger_name if logger_name else self._remote_node_name
         set_logger_level.level = logger_level
-        request.levels.append(set_logger_level)
+        request.levels.append(set_logger_level)  # type: ignore[attr-defined]
 
         future = self._logger_set_client.call_async(request)
         rclpy.spin_until_future_complete(self, future)
@@ -117,12 +120,15 @@ def set_logger_level_on_remote_node(self, logger_level, logger_name='') -> bool:
 
         return True
 
-    def get_logger_level_on_remote_node(self, logger_name=''):
+    def get_logger_level_on_remote_node(
+        self, logger_name: str = '',
+    ) -> list[object]:
         if not self.logger_get_client.service_is_ready():
             return [False, None]
 
         request = GetLoggerLevels.Request()
-        request.names.append(logger_name if logger_name else self._remote_node_name)
+        name = logger_name if logger_name else self._remote_node_name
+        request.names.append(name)  # type: ignore[attr-defined]
 
         future = self.logger_get_client.call_async(request)
         rclpy.spin_until_future_complete(self, future)
@@ -134,7 +140,7 @@ def get_logger_level_on_remote_node(self, logger_name=''):
         return [True, ret_results.levels[0].level]
 
 
-def get_logger_level_func(test_node, child_logger_name):
+def get_logger_level_func(test_node: TestNode, child_logger_name: str) -> None:
     ret, level = test_node.get_logger_level_on_remote_node()
     if ret:
         test_node.get_logger().info('Current logger level: ' + str(level))
@@ -147,7 +153,7 @@ def get_logger_level_func(test_node, child_logger_name):
         test_node.get_logger().error('Failed to get child logger level via logger service !')
 
 
-def main(args=None):
+def main(args: list[str] | None = None) -> None:
     # Check for --service-only flag before ROS 2 consumes the arguments
     parser = argparse.ArgumentParser(add_help=False)
     parser.add_argument('--service-only', action='store_true', default=False)
diff --git a/demo_nodes_py/demo_nodes_py/parameters/async_param_client.py b/demo_nodes_py/demo_nodes_py/parameters/async_param_client.py
index 7b014a027..5a2f4ccbd 100644
--- a/demo_nodes_py/demo_nodes_py/parameters/async_param_client.py
+++ b/demo_nodes_py/demo_nodes_py/parameters/async_param_client.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 # Copyright 2022 Open Source Robotics Foundation, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -23,7 +24,7 @@
 from rclpy.parameter_client import AsyncParameterClient
 
 
-def main(args=None):
+def main(args: list[str] | None = None) -> None:
     try:
         with rclpy.init():
             node = rclpy.create_node('async_param_client')
@@ -44,63 +45,64 @@ def main(args=None):
             rclpy.spin_until_future_complete(node, future)
             set_parameters_result = future.result()
             if set_parameters_result is not None:
-                for i, v in enumerate(set_parameters_result.results):
+                for i, set_param_result in enumerate(set_parameters_result.results):
                     logger.info(f'    {param_list[i]}:')
-                    logger.info(f'        successful: {v.successful}')
+                    logger.info(f'        successful: {set_param_result.successful}')
             else:
                 logger.error(f'Error setting parameters: {future.exception()}')
 
             logger.info('Listing Parameters:')
-            future = client.list_parameters(param_list, 10)
-            rclpy.spin_until_future_complete(node, future)
-            list_parameters_result = future.result()
+            list_future = client.list_parameters(param_list, 10)
+            rclpy.spin_until_future_complete(node, list_future)
+            list_parameters_result = list_future.result()
             if list_parameters_result is not None:
                 for param_name in list_parameters_result.result.names:
                     logger.info(f'    - {param_name}')
             else:
-                logger.error(f'Error listing parameters: {future.exception()}')
+                logger.error(f'Error listing parameters: {list_future.exception()}')
 
             logger.info('Getting parameters:')
-            future = client.get_parameters(param_list)
-            rclpy.spin_until_future_complete(node, future)
-            get_parameters_result = future.result()
+            get_future = client.get_parameters(param_list)
+            rclpy.spin_until_future_complete(node, get_future)
+            get_parameters_result = get_future.result()
             if get_parameters_result is not None:
-                for i, v in enumerate(get_parameters_result.values):
-                    logger.info(f'    - {param_list[i]}: {parameter_value_to_python(v)}')
+                for i, get_param_value in enumerate(get_parameters_result.values):
+                    logger.info(
+                        f'    - {param_list[i]}: {parameter_value_to_python(get_param_value)}')
             else:
-                logger.error(f'Error getting parameters: {future.exception()}')
+                logger.error(f'Error getting parameters: {get_future.exception()}')
 
             logger.info('Loading parameters: ')
             param_dir = get_package_share_directory('demo_nodes_py')
             param_file_path = os.path.join(param_dir, 'params.yaml')
-            future = client.load_parameter_file(param_file_path)
-            rclpy.spin_until_future_complete(node, future)
-            load_parameter_results = future.result()
+            load_future = client.load_parameter_file(param_file_path)
+            rclpy.spin_until_future_complete(node, load_future)
+            load_parameter_results = load_future.result()
             if load_parameter_results is not None:
                 param_file_dict = parameter_dict_from_yaml_file(
                     param_file_path, False, target_nodes=['parameter_blackboard'])
-                for i, v in enumerate(param_file_dict.keys()):
-                    logger.info(f'    {v}:')
+                for i, k in enumerate(param_file_dict.keys()):
+                    logger.info(f'    {k}:')
                     logger.info(f'        successful: '
                                 f'{load_parameter_results.results[i].successful}')
                     logger.info(f'        value: '
-                                f'{parameter_value_to_python(param_file_dict[v].value)}')
+                                f'{parameter_value_to_python(param_file_dict[k].value)}')
             else:
-                logger.error(f'Error loading parameters: {future.exception()}')
+                logger.error(f'Error loading parameters: {load_future.exception()}')
 
             logger.info('Deleting parameters: ')
             params_to_delete = ['other_int_parameter', 'other_string_parameter',
                                 'string_parameter']
-            future = client.delete_parameters(params_to_delete)
-            rclpy.spin_until_future_complete(node, future)
-            delete_parameters_result = future.result()
+            del_future = client.delete_parameters(params_to_delete)
+            rclpy.spin_until_future_complete(node, del_future)
+            delete_parameters_result = del_future.result()
             if delete_parameters_result is not None:
-                for i, v in enumerate(delete_parameters_result.results):
+                for i, del_param_result in enumerate(delete_parameters_result.results):
                     logger.info(f'    {params_to_delete[i]}:')
-                    logger.info(f'        successful: {v.successful}')
-                    logger.info(f'        reason: {v.reason}')
+                    logger.info(f'        successful: {del_param_result.successful}')
+                    logger.info(f'        reason: {del_param_result.reason}')
             else:
-                logger.error(f'Error deleting parameters: {future.exception()}')
+                logger.error(f'Error deleting parameters: {del_future.exception()}')
     except (KeyboardInterrupt, ExternalShutdownException):
         pass
 
diff --git a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
index 884a74721..934c11b88 100644
--- a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
+++ b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 # Copyright 2022 Open Source Robotics Foundation, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -28,7 +29,7 @@
 # and post_set parameter callbacks
 class SetParametersCallback(Node):
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__('set_parameters_callback')
 
         # tracks 'param1' value
@@ -38,7 +39,9 @@ def __init__(self):
 
         # setting another parameter from the callback is possible
         # we expect the callback to be called for param2
-        def pre_set_parameter_callback(parameter_list):
+        def pre_set_parameter_callback(
+            parameter_list: list[Parameter],  # type: ignore[type-arg]
+        ) -> list[Parameter]:  # type: ignore[type-arg]
             modified_parameters = parameter_list.copy()
             for param in parameter_list:
                 if param.name == 'param1':
@@ -47,7 +50,9 @@ def pre_set_parameter_callback(parameter_list):
             return modified_parameters
 
         # validation callback
-        def on_set_parameter_callback(parameter_list):
+        def on_set_parameter_callback(
+            parameter_list: list[Parameter],  # type: ignore[type-arg]
+        ) -> SetParametersResult:
             result = SetParametersResult()
             for param in parameter_list:
                 if param.name == 'param1':
@@ -60,7 +65,9 @@ def on_set_parameter_callback(parameter_list):
             return result
 
         # can change internally tracked class attributes
-        def post_set_parameter_callback(parameter_list):
+        def post_set_parameter_callback(
+            parameter_list: list[Parameter],  # type: ignore[type-arg]
+        ) -> None:
             for param in parameter_list:
                 if param.name == 'param1':
                     self.internal_tracked_param_1 = param.value
@@ -72,7 +79,7 @@ def post_set_parameter_callback(parameter_list):
         self.add_post_set_parameters_callback(post_set_parameter_callback)
 
 
-def main(args=None):
+def main(args: list[str] | None = None) -> None:
     try:
         with rclpy.init(args=args):
             node = SetParametersCallback()
diff --git a/demo_nodes_py/demo_nodes_py/services/add_two_ints_client.py b/demo_nodes_py/demo_nodes_py/services/add_two_ints_client.py
index 07ca330dc..e047f445b 100644
--- a/demo_nodes_py/demo_nodes_py/services/add_two_ints_client.py
+++ b/demo_nodes_py/demo_nodes_py/services/add_two_ints_client.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 # Copyright 2016 Open Source Robotics Foundation, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -18,7 +19,7 @@
 from rclpy.executors import ExternalShutdownException
 
 
-def main(args=None):
+def main(args: list[str] | None = None) -> None:
     try:
         with rclpy.init(args=args):
             node = rclpy.create_node('add_two_ints_client')
@@ -32,7 +33,8 @@ def main(args=None):
             future = cli.call_async(req)
             rclpy.spin_until_future_complete(node, future)
             if future.result() is not None:
-                node.get_logger().info('Result of add_two_ints: %d' % future.result().sum)
+                res_sum = future.result().sum  # type: ignore[union-attr]
+                node.get_logger().info('Result of add_two_ints: %d' % res_sum)
             else:
                 node.get_logger().error('Exception while calling service: %r' % future.exception())
     except (KeyboardInterrupt, ExternalShutdownException):
diff --git a/demo_nodes_py/demo_nodes_py/services/add_two_ints_client_async.py b/demo_nodes_py/demo_nodes_py/services/add_two_ints_client_async.py
index 8412df405..7804286e1 100644
--- a/demo_nodes_py/demo_nodes_py/services/add_two_ints_client_async.py
+++ b/demo_nodes_py/demo_nodes_py/services/add_two_ints_client_async.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 # Copyright 2016 Open Source Robotics Foundation, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -18,7 +19,7 @@
 from rclpy.executors import ExternalShutdownException
 
 
-def main(args=None):
+def main(args: list[str] | None = None) -> None:
     try:
         with rclpy.init(args=args):
             node = rclpy.create_node('add_two_ints_client')
@@ -38,7 +39,8 @@ def main(args=None):
                 rclpy.spin_once(node)
                 if future.done():
                     if future.result() is not None:
-                        logger.info('Result of add_two_ints: %d' % future.result().sum)
+                        res_sum = future.result().sum  # type: ignore[union-attr]
+                        logger.info('Result of add_two_ints: %d' % res_sum)
                     else:
                         logger.error('Exception while calling service: %r' % future.exception())
                     break
diff --git a/demo_nodes_py/demo_nodes_py/services/add_two_ints_server.py b/demo_nodes_py/demo_nodes_py/services/add_two_ints_server.py
index 92799b666..478a71473 100644
--- a/demo_nodes_py/demo_nodes_py/services/add_two_ints_server.py
+++ b/demo_nodes_py/demo_nodes_py/services/add_two_ints_server.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 # Copyright 2016 Open Source Robotics Foundation, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -21,18 +22,23 @@
 
 class AddTwoIntsServer(Node):
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__('add_two_ints_server')
-        self.srv = self.create_service(AddTwoInts, 'add_two_ints', self.add_two_ints_callback)
-
-    def add_two_ints_callback(self, request, response):
+        self.srv = self.create_service(
+            AddTwoInts, 'add_two_ints', self.add_two_ints_callback)
+
+    def add_two_ints_callback(
+        self,
+        request: AddTwoInts.Request,
+        response: AddTwoInts.Response,
+    ) -> AddTwoInts.Response:
         response.sum = request.a + request.b
         self.get_logger().info('Incoming request\na: %d b: %d' % (request.a, request.b))
 
         return response
 
 
-def main(args=None):
+def main(args: list[str] | None = None) -> None:
     try:
         with rclpy.init(args=args):
             node = AddTwoIntsServer()
diff --git a/demo_nodes_py/demo_nodes_py/services/introspection.py b/demo_nodes_py/demo_nodes_py/services/introspection.py
index 4712902ff..59985fab2 100644
--- a/demo_nodes_py/demo_nodes_py/services/introspection.py
+++ b/demo_nodes_py/demo_nodes_py/services/introspection.py
@@ -1,4 +1,5 @@
-# Copyright 2023 Open Source Robotics Foundation, Inc.
+#!/usr/bin/env python3
+# Copyright 2022 Open Source Robotics Foundation, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -22,6 +23,8 @@
 from rclpy.parameter import Parameter
 from rclpy.qos import qos_profile_system_default
 from rclpy.service_introspection import ServiceIntrospectionState
+from rclpy.task import Future
+from rclpy.timer import Timer
 
 
 # This demo program shows how to configure client and service introspection
@@ -69,7 +72,9 @@
 # In either case, service introspection data can be seen by running:
 #   ros2 topic echo /add_two_ints/_service_event
 
-def check_parameter(parameter_list, parameter_name):
+def check_parameter(
+    parameter_list: list[Parameter], parameter_name: str  # type: ignore[type-arg]
+) -> SetParametersResult:
     result = SetParametersResult()
     result.successful = True
     for param in parameter_list:
@@ -91,10 +96,14 @@ def check_parameter(parameter_list, parameter_name):
 
 class IntrospectionClientNode(Node):
 
-    def on_set_parameters_callback(self, parameter_list):
+    def on_set_parameters_callback(
+        self, parameter_list: list[Parameter],  # type: ignore[type-arg]
+    ) -> SetParametersResult:
         return check_parameter(parameter_list, 'client_configure_introspection')
 
-    def on_post_set_parameters_callback(self, parameter_list):
+    def on_post_set_parameters_callback(
+        self, parameter_list: list[Parameter],  # type: ignore[type-arg]
+    ) -> None:
         for param in parameter_list:
             if param.name != 'client_configure_introspection':
                 continue
@@ -111,7 +120,7 @@ def on_post_set_parameters_callback(self, parameter_list):
                                              introspection_state)
             break
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__('introspection_client')
 
         self.cli = self.create_client(AddTwoInts, 'add_two_ints')
@@ -120,10 +129,10 @@ def __init__(self):
         self.add_post_set_parameters_callback(self.on_post_set_parameters_callback)
         self.declare_parameter('client_configure_introspection', 'disabled')
 
-        self.timer = self.create_timer(0.5, self.timer_callback)
-        self.future = None
+        self.timer: Timer = self.create_timer(0.5, self.timer_callback)
+        self.future: Future[AddTwoInts.Response] | None = None
 
-    def timer_callback(self):
+    def timer_callback(self) -> None:
         if not self.cli.service_is_ready():
             return
 
@@ -140,7 +149,8 @@ def timer_callback(self):
             return
 
         if self.future.result() is not None:
-            self.get_logger().info('Result of add_two_ints: %d' % self.future.result().sum)
+            res_sum = self.future.result().sum  # type: ignore[union-attr]
+            self.get_logger().info('Result of add_two_ints: %d' % res_sum)
         else:
             self.get_logger().error('Exception calling service: %r' % self.future.exception())
 
@@ -149,10 +159,14 @@ def timer_callback(self):
 
 class IntrospectionServiceNode(Node):
 
-    def on_set_parameters_callback(self, parameter_list):
+    def on_set_parameters_callback(
+        self, parameter_list: list[Parameter],  # type: ignore[type-arg]
+    ) -> SetParametersResult:
         return check_parameter(parameter_list, 'service_configure_introspection')
 
-    def on_post_set_parameters_callback(self, parameter_list):
+    def on_post_set_parameters_callback(
+        self, parameter_list: list[Parameter],  # type: ignore[type-arg]
+    ) -> None:
         for param in parameter_list:
             if param.name != 'service_configure_introspection':
                 continue
@@ -169,23 +183,28 @@ def on_post_set_parameters_callback(self, parameter_list):
                                              introspection_state)
             break
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__('introspection_service')
 
-        self.srv = self.create_service(AddTwoInts, 'add_two_ints', self.add_two_ints_callback)
+        self.srv = self.create_service(
+            AddTwoInts, 'add_two_ints', self.add_two_ints_callback)
 
         self.add_on_set_parameters_callback(self.on_set_parameters_callback)
         self.add_post_set_parameters_callback(self.on_post_set_parameters_callback)
         self.declare_parameter('service_configure_introspection', 'disabled')
 
-    def add_two_ints_callback(self, request, response):
+    def add_two_ints_callback(
+        self,
+        request: AddTwoInts.Request,
+        response: AddTwoInts.Response,
+    ) -> AddTwoInts.Response:
         response.sum = request.a + request.b
         self.get_logger().info('Incoming request\na: %d b: %d' % (request.a, request.b))
 
         return response
 
 
-def main(args=None):
+def main(args: list[str] | None = None) -> None:
     try:
         with rclpy.init(args=args):
             service_node = IntrospectionServiceNode()
diff --git a/demo_nodes_py/demo_nodes_py/topics/listener.py b/demo_nodes_py/demo_nodes_py/topics/listener.py
index 9f4ea6171..be46db9f9 100644
--- a/demo_nodes_py/demo_nodes_py/topics/listener.py
+++ b/demo_nodes_py/demo_nodes_py/topics/listener.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 # Copyright 2016 Open Source Robotics Foundation, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -21,15 +22,16 @@
 
 class Listener(Node):
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__('listener')
-        self.sub = self.create_subscription(String, 'chatter', self.chatter_callback, 10)
+        self.sub = self.create_subscription(
+            String, 'chatter', self.chatter_callback, 10)
 
-    def chatter_callback(self, msg):
+    def chatter_callback(self, msg: String) -> None:
         self.get_logger().info('I heard: [%s]' % msg.data)
 
 
-def main(args=None):
+def main(args: list[str] | None = None) -> None:
     try:
         with rclpy.init(args=args):
             node = Listener()
diff --git a/demo_nodes_py/demo_nodes_py/topics/listener_qos.py b/demo_nodes_py/demo_nodes_py/topics/listener_qos.py
index 95e134591..40e7f3802 100644
--- a/demo_nodes_py/demo_nodes_py/topics/listener_qos.py
+++ b/demo_nodes_py/demo_nodes_py/topics/listener_qos.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 # Copyright 2016 Open Source Robotics Foundation, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -28,7 +29,7 @@
 
 class ListenerQos(Node):
 
-    def __init__(self, qos_profile):
+    def __init__(self, qos_profile: QoSProfile) -> None:
         super().__init__('listener_qos')
         if qos_profile.reliability is QoSReliabilityPolicy.RELIABLE:
             self.get_logger().info('Reliable listener')
@@ -37,11 +38,11 @@ def __init__(self, qos_profile):
         self.sub = self.create_subscription(
             String, 'chatter', self.chatter_callback, qos_profile)
 
-    def chatter_callback(self, msg):
+    def chatter_callback(self, msg: String) -> None:
         self.get_logger().info('I heard: [%s]' % msg.data)
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]) -> None:
     parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
     parser.add_argument(
         '--reliable', dest='reliable', action='store_true',
diff --git a/demo_nodes_py/demo_nodes_py/topics/listener_serialized.py b/demo_nodes_py/demo_nodes_py/topics/listener_serialized.py
index 25d49fc99..cdf45f3ff 100644
--- a/demo_nodes_py/demo_nodes_py/topics/listener_serialized.py
+++ b/demo_nodes_py/demo_nodes_py/topics/listener_serialized.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 # Copyright 2018 Open Source Robotics Foundation, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -21,7 +22,7 @@
 
 class SerializedSubscriber(Node):
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__('serialized_subscriber')
         self.subscription = self.create_subscription(
             String,
@@ -32,11 +33,11 @@ def __init__(self):
         # We're subscribing to the serialized bytes,
         # not example_interfaces.msg.String
 
-    def listener_callback(self, msg):
-        self.get_logger().info('I heard: "%s"' % msg)
+    def listener_callback(self, msg: bytes) -> None:
+        self.get_logger().info('I heard: "%r"' % msg)
 
 
-def main(args=None):
+def main(args: list[str] | None = None) -> None:
     try:
         with rclpy.init(args=args):
             serialized_subscriber = SerializedSubscriber()
diff --git a/demo_nodes_py/demo_nodes_py/topics/talker.py b/demo_nodes_py/demo_nodes_py/topics/talker.py
index 026b22d10..a596ab8f8 100644
--- a/demo_nodes_py/demo_nodes_py/topics/talker.py
+++ b/demo_nodes_py/demo_nodes_py/topics/talker.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 # Copyright 2016 Open Source Robotics Foundation, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -17,18 +18,19 @@
 import rclpy
 from rclpy.executors import ExternalShutdownException
 from rclpy.node import Node
+from rclpy.timer import Timer
 
 
 class Talker(Node):
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__('talker')
-        self.i = 0
+        self.i: int = 0
         self.pub = self.create_publisher(String, 'chatter', 10)
         timer_period = 1.0
-        self.tmr = self.create_timer(timer_period, self.timer_callback)
+        self.tmr: Timer = self.create_timer(timer_period, self.timer_callback)
 
-    def timer_callback(self):
+    def timer_callback(self) -> None:
         msg = String()
         msg.data = 'Hello World: {0}'.format(self.i)
         self.i += 1
@@ -36,7 +38,7 @@ def timer_callback(self):
         self.pub.publish(msg)
 
 
-def main(args=None):
+def main(args: list[str] | None = None) -> None:
     try:
         with rclpy.init(args=args):
             node = Talker()
diff --git a/demo_nodes_py/demo_nodes_py/topics/talker_qos.py b/demo_nodes_py/demo_nodes_py/topics/talker_qos.py
index 99c695e00..255d813a4 100644
--- a/demo_nodes_py/demo_nodes_py/topics/talker_qos.py
+++ b/demo_nodes_py/demo_nodes_py/topics/talker_qos.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 # Copyright 2016 Open Source Robotics Foundation, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -23,14 +24,15 @@
 from rclpy.qos import qos_profile_sensor_data
 from rclpy.qos import QoSProfile
 from rclpy.qos import QoSReliabilityPolicy
+from rclpy.timer import Timer
 from rclpy.utilities import remove_ros_args
 
 
 class TalkerQos(Node):
 
-    def __init__(self, qos_profile):
+    def __init__(self, qos_profile: QoSProfile) -> None:
         super().__init__('talker_qos')
-        self.i = 0
+        self.i: int = 0
         if qos_profile.reliability is QoSReliabilityPolicy.RELIABLE:
             self.get_logger().info('Reliable talker')
         else:
@@ -38,9 +40,9 @@ def __init__(self, qos_profile):
         self.pub = self.create_publisher(String, 'chatter', qos_profile)
 
         timer_period = 1.0
-        self.tmr = self.create_timer(timer_period, self.timer_callback)
+        self.tmr: Timer = self.create_timer(timer_period, self.timer_callback)
 
-    def timer_callback(self):
+    def timer_callback(self) -> None:
         msg = String()
         msg.data = 'Hello World: {0}'.format(self.i)
         self.i += 1
@@ -48,7 +50,7 @@ def timer_callback(self):
         self.pub.publish(msg)
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]) -> None:
     parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
     parser.add_argument(
         '--reliable', dest='reliable', action='store_true',
diff --git a/demo_nodes_py/package.xml b/demo_nodes_py/package.xml
index aa7e3ebde..bc9b4a113 100644
--- a/demo_nodes_py/package.xml
+++ b/demo_nodes_py/package.xml
@@ -26,6 +26,7 @@
   <test_depend>ament_copyright</test_depend>
   <test_depend>ament_flake8</test_depend>
   <test_depend>ament_pep257</test_depend>
+  <test_depend>ament_mypy</test_depend>
   <test_depend>ament_xmllint</test_depend>
   <test_depend>python3-pytest</test_depend>
 
diff --git a/demo_nodes_py/test/test_copyright.py b/demo_nodes_py/test/test_copyright.py
index cc8ff03f7..1f8698345 100644
--- a/demo_nodes_py/test/test_copyright.py
+++ b/demo_nodes_py/test/test_copyright.py
@@ -18,6 +18,6 @@
 
 @pytest.mark.copyright
 @pytest.mark.linter
-def test_copyright():
+def test_copyright() -> None:
     rc = main(argv=['.', 'test'])
     assert rc == 0, 'Found errors'
diff --git a/demo_nodes_py/test/test_flake8.py b/demo_nodes_py/test/test_flake8.py
index 27ee1078f..eac16eef9 100644
--- a/demo_nodes_py/test/test_flake8.py
+++ b/demo_nodes_py/test/test_flake8.py
@@ -18,7 +18,7 @@
 
 @pytest.mark.flake8
 @pytest.mark.linter
-def test_flake8():
+def test_flake8() -> None:
     rc, errors = main_with_errors(argv=[])
     assert rc == 0, \
         'Found %d code style errors / warnings:\n' % len(errors) + \
diff --git a/demo_nodes_py/test/test_mypy.py b/demo_nodes_py/test/test_mypy.py
new file mode 100644
index 000000000..9e7660fd2
--- /dev/null
+++ b/demo_nodes_py/test/test_mypy.py
@@ -0,0 +1,21 @@
+# Copyright 2026 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+from ament_mypy.main import main
+
+
+def test_mypy() -> None:
+    rc = main(argv=[])
+    assert rc == 0, 'Found code style errors / warnings'
diff --git a/demo_nodes_py/test/test_pep257.py b/demo_nodes_py/test/test_pep257.py
index b234a3840..b6808e1d8 100644
--- a/demo_nodes_py/test/test_pep257.py
+++ b/demo_nodes_py/test/test_pep257.py
@@ -18,6 +18,6 @@
 
 @pytest.mark.linter
 @pytest.mark.pep257
-def test_pep257():
+def test_pep257() -> None:
     rc = main(argv=['.', 'test'])
     assert rc == 0, 'Found code style errors / warnings'

From 08df12c287f84fdda53be20796c3bc37fad7f488 Mon Sep 17 00:00:00 2001
From: Jonathan Setiawan <jonathanrustam2@gmail.com>
Date: Wed, 18 Mar 2026 09:19:24 +0900
Subject: [PATCH 02/11] fix types for python 3.9, add safety checks, and use
 --ament-strict

Signed-off-by: Jonathan Setiawan <jonathanrustam2@gmail.com>
---
 .../events/matched_event_detect.py            | 19 ++++++++------
 .../logging/use_logger_service.py             | 25 +++++++++++--------
 .../parameters/set_parameters_callback.py     | 13 ++++++----
 .../services/add_two_ints_client.py           | 10 +++++---
 .../services/add_two_ints_client_async.py     | 10 +++++---
 .../demo_nodes_py/services/introspection.py   | 17 +++++++------
 demo_nodes_py/demo_nodes_py/topics/talker.py  |  8 +++---
 .../demo_nodes_py/topics/talker_qos.py        |  6 ++---
 demo_nodes_py/test/test_mypy.py               |  2 +-
 9 files changed, 67 insertions(+), 43 deletions(-)

diff --git a/demo_nodes_py/demo_nodes_py/events/matched_event_detect.py b/demo_nodes_py/demo_nodes_py/events/matched_event_detect.py
index 3eade3da0..69cb81dae 100644
--- a/demo_nodes_py/demo_nodes_py/events/matched_event_detect.py
+++ b/demo_nodes_py/demo_nodes_py/events/matched_event_detect.py
@@ -12,6 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import List
+from typing import Union
+
 from example_interfaces.msg import String
 import rclpy
 from rclpy.event_handler import PublisherEventCallbacks
@@ -86,7 +89,7 @@ def __sub_matched_event_callback(self, info: QoSSubscriptionMatchedInfo) -> None
 
         self.future.set_result(True)
 
-    def get_future(self) -> Future:  # type: ignore[type-arg]
+    def get_future(self) -> Future[bool]:
         self.future: Future[bool] = Future()
         return self.future
 
@@ -95,7 +98,7 @@ class MultiSubNode(Node):
 
     def __init__(self, topic_name: str):
         super().__init__('multi_sub_node')
-        self.__subs: list[Subscription] = []  # type: ignore[type-arg]
+        self.__subs: List[Subscription[String]] = []
         self.__topic_name = topic_name
 
     def create_one_sub(self) -> Subscription[String]:
@@ -104,7 +107,7 @@ def create_one_sub(self) -> Subscription[String]:
         self.__subs.append(sub)
         return sub
 
-    def destroy_one_sub(self, sub: Subscription) -> None:  # type: ignore[type-arg]
+    def destroy_one_sub(self, sub: Subscription[String]) -> None:
 
         if sub in self.__subs:
             self.get_logger().info('Destroy a subscription.')
@@ -116,7 +119,7 @@ class MultiPubNode(Node):
 
     def __init__(self, topic_name: str):
         super().__init__('multi_pub_node')
-        self.__pubs: list[Publisher] = []  # type: ignore[type-arg]
+        self.__pubs: List[Publisher[String]] = []
         self.__topic_name = topic_name
 
     def create_one_pub(self) -> Publisher[String]:
@@ -125,7 +128,7 @@ def create_one_pub(self) -> Publisher[String]:
         self.__pubs.append(pub)
         return pub
 
-    def destroy_one_pub(self, pub: Publisher) -> None:  # type: ignore[type-arg]
+    def destroy_one_pub(self, pub: Publisher[String]) -> None:
 
         if pub in self.__pubs:
             self.get_logger().info('Destroy a publisher.')
@@ -133,11 +136,11 @@ def destroy_one_pub(self, pub: Publisher) -> None:  # type: ignore[type-arg]
             self.destroy_publisher(pub)
 
 
-def main(args: list[str] | None = None) -> None:
+def main(args: Union[List[str], None] = None) -> None:
     try:
         with rclpy.init(args=args):
-            topic_name_for_detect_pub_matched_event: str = 'pub_topic_matched_event_detect'
-            topic_name_for_detect_sub_matched_event: str = 'sub_topic_matched_event_detect'
+            topic_name_for_detect_pub_matched_event = 'pub_topic_matched_event_detect'
+            topic_name_for_detect_sub_matched_event = 'sub_topic_matched_event_detect'
 
             matched_node = MatchedEventDetectNode(
                 topic_name_for_detect_pub_matched_event, topic_name_for_detect_sub_matched_event)
diff --git a/demo_nodes_py/demo_nodes_py/logging/use_logger_service.py b/demo_nodes_py/demo_nodes_py/logging/use_logger_service.py
index 85ad83e13..7ec1c05eb 100644
--- a/demo_nodes_py/demo_nodes_py/logging/use_logger_service.py
+++ b/demo_nodes_py/demo_nodes_py/logging/use_logger_service.py
@@ -12,10 +12,13 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
 import argparse
 import threading
 import time
+from typing import List
+from typing import Literal
+from typing import Tuple
+from typing import Union
 
 from example_interfaces.msg import String
 from rcl_interfaces.msg import LoggerLevel
@@ -104,7 +107,7 @@ def set_logger_level_on_remote_node(
         set_logger_level = LoggerLevel()
         set_logger_level.name = logger_name if logger_name else self._remote_node_name
         set_logger_level.level = logger_level
-        request.levels.append(set_logger_level)  # type: ignore[attr-defined]
+        request.levels = [set_logger_level]
 
         future = self._logger_set_client.call_async(request)
         rclpy.spin_until_future_complete(self, future)
@@ -122,38 +125,40 @@ def set_logger_level_on_remote_node(
 
     def get_logger_level_on_remote_node(
         self, logger_name: str = '',
-    ) -> list[object]:
+    ) -> List[Union[Tuple[Literal[False], None], Tuple[Literal[True], int]]]:
         if not self.logger_get_client.service_is_ready():
-            return [False, None]
+            return [(False, None)]
 
         request = GetLoggerLevels.Request()
         name = logger_name if logger_name else self._remote_node_name
-        request.names.append(name)  # type: ignore[attr-defined]
+        request.names = [name]
 
         future = self.logger_get_client.call_async(request)
         rclpy.spin_until_future_complete(self, future)
 
         ret_results = future.result()
         if not ret_results:
-            return [False, None]
+            return [(False, None)]
 
-        return [True, ret_results.levels[0].level]
+        return [(True, ret_results.levels[0].level)]
 
 
 def get_logger_level_func(test_node: TestNode, child_logger_name: str) -> None:
-    ret, level = test_node.get_logger_level_on_remote_node()
+    results = test_node.get_logger_level_on_remote_node()
+    ret, level = results[0]
     if ret:
         test_node.get_logger().info('Current logger level: ' + str(level))
     else:
         test_node.get_logger().error('Failed to get logger level via logger service !')
-    ret, child_level = test_node.get_logger_level_on_remote_node(child_logger_name)
+    child_results = test_node.get_logger_level_on_remote_node(child_logger_name)
+    ret, child_level = child_results[0]
     if ret:
         test_node.get_logger().info('Current child logger level: ' + str(child_level))
     else:
         test_node.get_logger().error('Failed to get child logger level via logger service !')
 
 
-def main(args: list[str] | None = None) -> None:
+def main(args: Union[List[str], None] = None) -> None:
     # Check for --service-only flag before ROS 2 consumes the arguments
     parser = argparse.ArgumentParser(add_help=False)
     parser.add_argument('--service-only', action='store_true', default=False)
diff --git a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
index 934c11b88..a4d8f0ad7 100644
--- a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
+++ b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
@@ -13,6 +13,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import List
+from typing import Union
+
 from rcl_interfaces.msg import SetParametersResult
 
 import rclpy
@@ -40,8 +43,8 @@ def __init__(self) -> None:
         # setting another parameter from the callback is possible
         # we expect the callback to be called for param2
         def pre_set_parameter_callback(
-            parameter_list: list[Parameter],  # type: ignore[type-arg]
-        ) -> list[Parameter]:  # type: ignore[type-arg]
+            parameter_list: List[Parameter],  # type: ignore[type-arg]
+        ) -> List[Parameter]:  # type: ignore[type-arg]
             modified_parameters = parameter_list.copy()
             for param in parameter_list:
                 if param.name == 'param1':
@@ -51,7 +54,7 @@ def pre_set_parameter_callback(
 
         # validation callback
         def on_set_parameter_callback(
-            parameter_list: list[Parameter],  # type: ignore[type-arg]
+            parameter_list: List[Parameter],  # type: ignore[type-arg]
         ) -> SetParametersResult:
             result = SetParametersResult()
             for param in parameter_list:
@@ -66,7 +69,7 @@ def on_set_parameter_callback(
 
         # can change internally tracked class attributes
         def post_set_parameter_callback(
-            parameter_list: list[Parameter],  # type: ignore[type-arg]
+            parameter_list: List[Parameter],  # type: ignore[type-arg]
         ) -> None:
             for param in parameter_list:
                 if param.name == 'param1':
@@ -79,7 +82,7 @@ def post_set_parameter_callback(
         self.add_post_set_parameters_callback(post_set_parameter_callback)
 
 
-def main(args: list[str] | None = None) -> None:
+def main(args: Union[List[str], None] = None) -> None:
     try:
         with rclpy.init(args=args):
             node = SetParametersCallback()
diff --git a/demo_nodes_py/demo_nodes_py/services/add_two_ints_client.py b/demo_nodes_py/demo_nodes_py/services/add_two_ints_client.py
index e047f445b..d54e2a7ad 100644
--- a/demo_nodes_py/demo_nodes_py/services/add_two_ints_client.py
+++ b/demo_nodes_py/demo_nodes_py/services/add_two_ints_client.py
@@ -13,13 +13,16 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import List
+from typing import Union
+
 from example_interfaces.srv import AddTwoInts
 
 import rclpy
 from rclpy.executors import ExternalShutdownException
 
 
-def main(args: list[str] | None = None) -> None:
+def main(args: Union[List[str], None] = None) -> None:
     try:
         with rclpy.init(args=args):
             node = rclpy.create_node('add_two_ints_client')
@@ -32,8 +35,9 @@ def main(args: list[str] | None = None) -> None:
             req.b = 3
             future = cli.call_async(req)
             rclpy.spin_until_future_complete(node, future)
-            if future.result() is not None:
-                res_sum = future.result().sum  # type: ignore[union-attr]
+            result = future.result()
+            if result is not None:
+                res_sum = result.sum
                 node.get_logger().info('Result of add_two_ints: %d' % res_sum)
             else:
                 node.get_logger().error('Exception while calling service: %r' % future.exception())
diff --git a/demo_nodes_py/demo_nodes_py/services/add_two_ints_client_async.py b/demo_nodes_py/demo_nodes_py/services/add_two_ints_client_async.py
index 7804286e1..4f3d7dc05 100644
--- a/demo_nodes_py/demo_nodes_py/services/add_two_ints_client_async.py
+++ b/demo_nodes_py/demo_nodes_py/services/add_two_ints_client_async.py
@@ -13,13 +13,16 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import List
+from typing import Union
+
 from example_interfaces.srv import AddTwoInts
 
 import rclpy
 from rclpy.executors import ExternalShutdownException
 
 
-def main(args: list[str] | None = None) -> None:
+def main(args: Union[List[str], None] = None) -> None:
     try:
         with rclpy.init(args=args):
             node = rclpy.create_node('add_two_ints_client')
@@ -38,8 +41,9 @@ def main(args: list[str] | None = None) -> None:
             while rclpy.ok():
                 rclpy.spin_once(node)
                 if future.done():
-                    if future.result() is not None:
-                        res_sum = future.result().sum  # type: ignore[union-attr]
+                    result = future.result()
+                    if result is not None:
+                        res_sum = result.sum
                         logger.info('Result of add_two_ints: %d' % res_sum)
                     else:
                         logger.error('Exception while calling service: %r' % future.exception())
diff --git a/demo_nodes_py/demo_nodes_py/services/introspection.py b/demo_nodes_py/demo_nodes_py/services/introspection.py
index 59985fab2..25a8f48ac 100644
--- a/demo_nodes_py/demo_nodes_py/services/introspection.py
+++ b/demo_nodes_py/demo_nodes_py/services/introspection.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# Copyright 2022 Open Source Robotics Foundation, Inc.
+# Copyright 2023 Open Source Robotics Foundation, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -13,6 +13,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import List
+from typing import Union
+
 from example_interfaces.srv import AddTwoInts
 from rcl_interfaces.msg import SetParametersResult
 
@@ -73,7 +76,7 @@
 #   ros2 topic echo /add_two_ints/_service_event
 
 def check_parameter(
-    parameter_list: list[Parameter], parameter_name: str  # type: ignore[type-arg]
+    parameter_list: List[Parameter], parameter_name: str  # type: ignore[type-arg]
 ) -> SetParametersResult:
     result = SetParametersResult()
     result.successful = True
@@ -97,12 +100,12 @@ def check_parameter(
 class IntrospectionClientNode(Node):
 
     def on_set_parameters_callback(
-        self, parameter_list: list[Parameter],  # type: ignore[type-arg]
+        self, parameter_list: List[Parameter],  # type: ignore[type-arg]
     ) -> SetParametersResult:
         return check_parameter(parameter_list, 'client_configure_introspection')
 
     def on_post_set_parameters_callback(
-        self, parameter_list: list[Parameter],  # type: ignore[type-arg]
+        self, parameter_list: List[Parameter],  # type: ignore[type-arg]
     ) -> None:
         for param in parameter_list:
             if param.name != 'client_configure_introspection':
@@ -160,12 +163,12 @@ def timer_callback(self) -> None:
 class IntrospectionServiceNode(Node):
 
     def on_set_parameters_callback(
-        self, parameter_list: list[Parameter],  # type: ignore[type-arg]
+        self, parameter_list: List[Parameter],  # type: ignore[type-arg]
     ) -> SetParametersResult:
         return check_parameter(parameter_list, 'service_configure_introspection')
 
     def on_post_set_parameters_callback(
-        self, parameter_list: list[Parameter],  # type: ignore[type-arg]
+        self, parameter_list: List[Parameter],  # type: ignore[type-arg]
     ) -> None:
         for param in parameter_list:
             if param.name != 'service_configure_introspection':
@@ -204,7 +207,7 @@ def add_two_ints_callback(
         return response
 
 
-def main(args: list[str] | None = None) -> None:
+def main(args: Union[List[str], None] = None) -> None:
     try:
         with rclpy.init(args=args):
             service_node = IntrospectionServiceNode()
diff --git a/demo_nodes_py/demo_nodes_py/topics/talker.py b/demo_nodes_py/demo_nodes_py/topics/talker.py
index a596ab8f8..9d20195df 100644
--- a/demo_nodes_py/demo_nodes_py/topics/talker.py
+++ b/demo_nodes_py/demo_nodes_py/topics/talker.py
@@ -13,12 +13,14 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import List
+from typing import Union
+
 from example_interfaces.msg import String
 
 import rclpy
 from rclpy.executors import ExternalShutdownException
 from rclpy.node import Node
-from rclpy.timer import Timer
 
 
 class Talker(Node):
@@ -28,7 +30,7 @@ def __init__(self) -> None:
         self.i: int = 0
         self.pub = self.create_publisher(String, 'chatter', 10)
         timer_period = 1.0
-        self.tmr: Timer = self.create_timer(timer_period, self.timer_callback)
+        self.tmr = self.create_timer(timer_period, self.timer_callback)
 
     def timer_callback(self) -> None:
         msg = String()
@@ -38,7 +40,7 @@ def timer_callback(self) -> None:
         self.pub.publish(msg)
 
 
-def main(args: list[str] | None = None) -> None:
+def main(args: Union[List[str], None] = None) -> None:
     try:
         with rclpy.init(args=args):
             node = Talker()
diff --git a/demo_nodes_py/demo_nodes_py/topics/talker_qos.py b/demo_nodes_py/demo_nodes_py/topics/talker_qos.py
index 255d813a4..3d14dd59a 100644
--- a/demo_nodes_py/demo_nodes_py/topics/talker_qos.py
+++ b/demo_nodes_py/demo_nodes_py/topics/talker_qos.py
@@ -15,6 +15,7 @@
 
 import argparse
 import sys
+from typing import List
 
 from example_interfaces.msg import String
 
@@ -24,7 +25,6 @@
 from rclpy.qos import qos_profile_sensor_data
 from rclpy.qos import QoSProfile
 from rclpy.qos import QoSReliabilityPolicy
-from rclpy.timer import Timer
 from rclpy.utilities import remove_ros_args
 
 
@@ -40,7 +40,7 @@ def __init__(self, qos_profile: QoSProfile) -> None:
         self.pub = self.create_publisher(String, 'chatter', qos_profile)
 
         timer_period = 1.0
-        self.tmr: Timer = self.create_timer(timer_period, self.timer_callback)
+        self.tmr = self.create_timer(timer_period, self.timer_callback)
 
     def timer_callback(self) -> None:
         msg = String()
@@ -50,7 +50,7 @@ def timer_callback(self) -> None:
         self.pub.publish(msg)
 
 
-def main(argv: list[str] = sys.argv[1:]) -> None:
+def main(argv: List[str] = sys.argv[1:]) -> None:
     parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
     parser.add_argument(
         '--reliable', dest='reliable', action='store_true',
diff --git a/demo_nodes_py/test/test_mypy.py b/demo_nodes_py/test/test_mypy.py
index 9e7660fd2..afc6a332c 100644
--- a/demo_nodes_py/test/test_mypy.py
+++ b/demo_nodes_py/test/test_mypy.py
@@ -17,5 +17,5 @@
 
 
 def test_mypy() -> None:
-    rc = main(argv=[])
+    rc = main()
     assert rc == 0, 'Found code style errors / warnings'

From c8c2935bfb2e56cdb9b40c1fba83c3824999c9e6 Mon Sep 17 00:00:00 2001
From: Jonathan Setiawan <jonathanrustam2@gmail.com>
Date: Sun, 22 Mar 2026 00:40:10 +0900
Subject: [PATCH 03/11] revert formatting, fix python 3.9 compatibility, and
 PEP 585 typing

Signed-off-by: Jonathan Setiawan <jonathanrustam2@gmail.com>
---
 .../events/matched_event_detect.py            |  7 +++---
 .../logging/use_logger_service.py             | 17 +++++++-------
 .../parameters/set_parameters_callback.py     | 11 +++++-----
 .../services/add_two_ints_client.py           |  3 +--
 .../services/add_two_ints_client_async.py     |  3 +--
 .../demo_nodes_py/services/introspection.py   | 22 +++++++++----------
 .../topics/listener_serialized.py             | 11 +++++-----
 demo_nodes_py/demo_nodes_py/topics/talker.py  |  5 ++---
 .../demo_nodes_py/topics/talker_qos.py        |  3 +--
 demo_nodes_py/test/test_mypy.py               |  2 +-
 10 files changed, 38 insertions(+), 46 deletions(-)

diff --git a/demo_nodes_py/demo_nodes_py/events/matched_event_detect.py b/demo_nodes_py/demo_nodes_py/events/matched_event_detect.py
index 69cb81dae..d72c00f45 100644
--- a/demo_nodes_py/demo_nodes_py/events/matched_event_detect.py
+++ b/demo_nodes_py/demo_nodes_py/events/matched_event_detect.py
@@ -12,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import List
 from typing import Union
 
 from example_interfaces.msg import String
@@ -98,7 +97,7 @@ class MultiSubNode(Node):
 
     def __init__(self, topic_name: str):
         super().__init__('multi_sub_node')
-        self.__subs: List[Subscription[String]] = []
+        self.__subs: list[Subscription[String]] = []
         self.__topic_name = topic_name
 
     def create_one_sub(self) -> Subscription[String]:
@@ -119,7 +118,7 @@ class MultiPubNode(Node):
 
     def __init__(self, topic_name: str):
         super().__init__('multi_pub_node')
-        self.__pubs: List[Publisher[String]] = []
+        self.__pubs: list[Publisher[String]] = []
         self.__topic_name = topic_name
 
     def create_one_pub(self) -> Publisher[String]:
@@ -136,7 +135,7 @@ def destroy_one_pub(self, pub: Publisher[String]) -> None:
             self.destroy_publisher(pub)
 
 
-def main(args: Union[List[str], None] = None) -> None:
+def main(args: Union[list[str], None] = None) -> None:
     try:
         with rclpy.init(args=args):
             topic_name_for_detect_pub_matched_event = 'pub_topic_matched_event_detect'
diff --git a/demo_nodes_py/demo_nodes_py/logging/use_logger_service.py b/demo_nodes_py/demo_nodes_py/logging/use_logger_service.py
index 7ec1c05eb..4d331e6bf 100644
--- a/demo_nodes_py/demo_nodes_py/logging/use_logger_service.py
+++ b/demo_nodes_py/demo_nodes_py/logging/use_logger_service.py
@@ -12,12 +12,11 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 import argparse
 import threading
 import time
-from typing import List
 from typing import Literal
-from typing import Tuple
 from typing import Union
 
 from example_interfaces.msg import String
@@ -107,7 +106,7 @@ def set_logger_level_on_remote_node(
         set_logger_level = LoggerLevel()
         set_logger_level.name = logger_name if logger_name else self._remote_node_name
         set_logger_level.level = logger_level
-        request.levels = [set_logger_level]
+        request.levels.append(set_logger_level)
 
         future = self._logger_set_client.call_async(request)
         rclpy.spin_until_future_complete(self, future)
@@ -125,9 +124,9 @@ def set_logger_level_on_remote_node(
 
     def get_logger_level_on_remote_node(
         self, logger_name: str = '',
-    ) -> List[Union[Tuple[Literal[False], None], Tuple[Literal[True], int]]]:
+    ) -> Union[tuple[Literal[False], None], tuple[Literal[True], int]]:
         if not self.logger_get_client.service_is_ready():
-            return [(False, None)]
+            return False, None
 
         request = GetLoggerLevels.Request()
         name = logger_name if logger_name else self._remote_node_name
@@ -140,25 +139,25 @@ def get_logger_level_on_remote_node(
         if not ret_results:
             return [(False, None)]
 
-        return [(True, ret_results.levels[0].level)]
+        return True, ret_results.levels[0].level
 
 
 def get_logger_level_func(test_node: TestNode, child_logger_name: str) -> None:
     results = test_node.get_logger_level_on_remote_node()
-    ret, level = results[0]
+    ret, level = results
     if ret:
         test_node.get_logger().info('Current logger level: ' + str(level))
     else:
         test_node.get_logger().error('Failed to get logger level via logger service !')
     child_results = test_node.get_logger_level_on_remote_node(child_logger_name)
-    ret, child_level = child_results[0]
+    ret, child_level = child_results
     if ret:
         test_node.get_logger().info('Current child logger level: ' + str(child_level))
     else:
         test_node.get_logger().error('Failed to get child logger level via logger service !')
 
 
-def main(args: Union[List[str], None] = None) -> None:
+def main(args: Union[list[str], None] = None) -> None:
     # Check for --service-only flag before ROS 2 consumes the arguments
     parser = argparse.ArgumentParser(add_help=False)
     parser.add_argument('--service-only', action='store_true', default=False)
diff --git a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
index a4d8f0ad7..64ca79ccc 100644
--- a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
+++ b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
@@ -13,7 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import List
 from typing import Union
 
 from rcl_interfaces.msg import SetParametersResult
@@ -43,8 +42,8 @@ def __init__(self) -> None:
         # setting another parameter from the callback is possible
         # we expect the callback to be called for param2
         def pre_set_parameter_callback(
-            parameter_list: List[Parameter],  # type: ignore[type-arg]
-        ) -> List[Parameter]:  # type: ignore[type-arg]
+            parameter_list: list[Parameter],
+        ) -> list[Parameter]:
             modified_parameters = parameter_list.copy()
             for param in parameter_list:
                 if param.name == 'param1':
@@ -54,7 +53,7 @@ def pre_set_parameter_callback(
 
         # validation callback
         def on_set_parameter_callback(
-            parameter_list: List[Parameter],  # type: ignore[type-arg]
+            parameter_list: list[Parameter],
         ) -> SetParametersResult:
             result = SetParametersResult()
             for param in parameter_list:
@@ -69,7 +68,7 @@ def on_set_parameter_callback(
 
         # can change internally tracked class attributes
         def post_set_parameter_callback(
-            parameter_list: List[Parameter],  # type: ignore[type-arg]
+            parameter_list: list[Parameter],
         ) -> None:
             for param in parameter_list:
                 if param.name == 'param1':
@@ -82,7 +81,7 @@ def post_set_parameter_callback(
         self.add_post_set_parameters_callback(post_set_parameter_callback)
 
 
-def main(args: Union[List[str], None] = None) -> None:
+def main(args: Union[list[str], None] = None) -> None:
     try:
         with rclpy.init(args=args):
             node = SetParametersCallback()
diff --git a/demo_nodes_py/demo_nodes_py/services/add_two_ints_client.py b/demo_nodes_py/demo_nodes_py/services/add_two_ints_client.py
index d54e2a7ad..34edabd07 100644
--- a/demo_nodes_py/demo_nodes_py/services/add_two_ints_client.py
+++ b/demo_nodes_py/demo_nodes_py/services/add_two_ints_client.py
@@ -13,7 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import List
 from typing import Union
 
 from example_interfaces.srv import AddTwoInts
@@ -22,7 +21,7 @@
 from rclpy.executors import ExternalShutdownException
 
 
-def main(args: Union[List[str], None] = None) -> None:
+def main(args: Union[list[str], None] = None) -> None:
     try:
         with rclpy.init(args=args):
             node = rclpy.create_node('add_two_ints_client')
diff --git a/demo_nodes_py/demo_nodes_py/services/add_two_ints_client_async.py b/demo_nodes_py/demo_nodes_py/services/add_two_ints_client_async.py
index 4f3d7dc05..6d88191b7 100644
--- a/demo_nodes_py/demo_nodes_py/services/add_two_ints_client_async.py
+++ b/demo_nodes_py/demo_nodes_py/services/add_two_ints_client_async.py
@@ -13,7 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import List
 from typing import Union
 
 from example_interfaces.srv import AddTwoInts
@@ -22,7 +21,7 @@
 from rclpy.executors import ExternalShutdownException
 
 
-def main(args: Union[List[str], None] = None) -> None:
+def main(args: Union[list[str], None] = None) -> None:
     try:
         with rclpy.init(args=args):
             node = rclpy.create_node('add_two_ints_client')
diff --git a/demo_nodes_py/demo_nodes_py/services/introspection.py b/demo_nodes_py/demo_nodes_py/services/introspection.py
index 25a8f48ac..59a9e72a8 100644
--- a/demo_nodes_py/demo_nodes_py/services/introspection.py
+++ b/demo_nodes_py/demo_nodes_py/services/introspection.py
@@ -13,7 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import List
 from typing import Union
 
 from example_interfaces.srv import AddTwoInts
@@ -76,7 +75,7 @@
 #   ros2 topic echo /add_two_ints/_service_event
 
 def check_parameter(
-    parameter_list: List[Parameter], parameter_name: str  # type: ignore[type-arg]
+    parameter_list: list[Parameter], parameter_name: str
 ) -> SetParametersResult:
     result = SetParametersResult()
     result.successful = True
@@ -100,12 +99,12 @@ def check_parameter(
 class IntrospectionClientNode(Node):
 
     def on_set_parameters_callback(
-        self, parameter_list: List[Parameter],  # type: ignore[type-arg]
+        self, parameter_list: list[Parameter],
     ) -> SetParametersResult:
         return check_parameter(parameter_list, 'client_configure_introspection')
 
     def on_post_set_parameters_callback(
-        self, parameter_list: List[Parameter],  # type: ignore[type-arg]
+        self, parameter_list: list[Parameter],
     ) -> None:
         for param in parameter_list:
             if param.name != 'client_configure_introspection':
@@ -132,8 +131,8 @@ def __init__(self) -> None:
         self.add_post_set_parameters_callback(self.on_post_set_parameters_callback)
         self.declare_parameter('client_configure_introspection', 'disabled')
 
-        self.timer: Timer = self.create_timer(0.5, self.timer_callback)
-        self.future: Future[AddTwoInts.Response] | None = None
+        self.timer = self.create_timer(0.5, self.timer_callback)
+        self.future: Union[Future[AddTwoInts.Response], None] = None
 
     def timer_callback(self) -> None:
         if not self.cli.service_is_ready():
@@ -151,8 +150,9 @@ def timer_callback(self) -> None:
         if not self.future.done():
             return
 
-        if self.future.result() is not None:
-            res_sum = self.future.result().sum  # type: ignore[union-attr]
+        result = self.future.result()
+        if result is not None:
+            res_sum = result.sum
             self.get_logger().info('Result of add_two_ints: %d' % res_sum)
         else:
             self.get_logger().error('Exception calling service: %r' % self.future.exception())
@@ -163,12 +163,12 @@ def timer_callback(self) -> None:
 class IntrospectionServiceNode(Node):
 
     def on_set_parameters_callback(
-        self, parameter_list: List[Parameter],  # type: ignore[type-arg]
+        self, parameter_list: list[Parameter],
     ) -> SetParametersResult:
         return check_parameter(parameter_list, 'service_configure_introspection')
 
     def on_post_set_parameters_callback(
-        self, parameter_list: List[Parameter],  # type: ignore[type-arg]
+        self, parameter_list: list[Parameter],
     ) -> None:
         for param in parameter_list:
             if param.name != 'service_configure_introspection':
@@ -207,7 +207,7 @@ def add_two_ints_callback(
         return response
 
 
-def main(args: Union[List[str], None] = None) -> None:
+def main(args: Union[list[str], None] = None) -> None:
     try:
         with rclpy.init(args=args):
             service_node = IntrospectionServiceNode()
diff --git a/demo_nodes_py/demo_nodes_py/topics/listener_serialized.py b/demo_nodes_py/demo_nodes_py/topics/listener_serialized.py
index cdf45f3ff..b929be023 100644
--- a/demo_nodes_py/demo_nodes_py/topics/listener_serialized.py
+++ b/demo_nodes_py/demo_nodes_py/topics/listener_serialized.py
@@ -13,15 +13,16 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from ctypes import Union
+
 from example_interfaces.msg import String
+from typing import Union
 
 import rclpy
 from rclpy.executors import ExternalShutdownException
 from rclpy.node import Node
 
-
 class SerializedSubscriber(Node):
-
     def __init__(self) -> None:
         super().__init__('serialized_subscriber')
         self.subscription = self.create_subscription(
@@ -34,10 +35,9 @@ def __init__(self) -> None:
         # not example_interfaces.msg.String
 
     def listener_callback(self, msg: bytes) -> None:
-        self.get_logger().info('I heard: "%r"' % msg)
+        self.get_logger().info('I heard: "%s"' % msg)
 
-
-def main(args: list[str] | None = None) -> None:
+def main(args: Union[list[str], None] = None) -> None:
     try:
         with rclpy.init(args=args):
             serialized_subscriber = SerializedSubscriber()
@@ -46,6 +46,5 @@ def main(args: list[str] | None = None) -> None:
     except (KeyboardInterrupt, ExternalShutdownException):
         pass
 
-
 if __name__ == '__main__':
     main()
diff --git a/demo_nodes_py/demo_nodes_py/topics/talker.py b/demo_nodes_py/demo_nodes_py/topics/talker.py
index 9d20195df..4f16db25b 100644
--- a/demo_nodes_py/demo_nodes_py/topics/talker.py
+++ b/demo_nodes_py/demo_nodes_py/topics/talker.py
@@ -13,7 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import List
 from typing import Union
 
 from example_interfaces.msg import String
@@ -27,7 +26,7 @@ class Talker(Node):
 
     def __init__(self) -> None:
         super().__init__('talker')
-        self.i: int = 0
+        self.i = 0
         self.pub = self.create_publisher(String, 'chatter', 10)
         timer_period = 1.0
         self.tmr = self.create_timer(timer_period, self.timer_callback)
@@ -40,7 +39,7 @@ def timer_callback(self) -> None:
         self.pub.publish(msg)
 
 
-def main(args: Union[List[str], None] = None) -> None:
+def main(args: Union[list[str], None] = None) -> None:
     try:
         with rclpy.init(args=args):
             node = Talker()
diff --git a/demo_nodes_py/demo_nodes_py/topics/talker_qos.py b/demo_nodes_py/demo_nodes_py/topics/talker_qos.py
index 3d14dd59a..644b51b28 100644
--- a/demo_nodes_py/demo_nodes_py/topics/talker_qos.py
+++ b/demo_nodes_py/demo_nodes_py/topics/talker_qos.py
@@ -15,7 +15,6 @@
 
 import argparse
 import sys
-from typing import List
 
 from example_interfaces.msg import String
 
@@ -50,7 +49,7 @@ def timer_callback(self) -> None:
         self.pub.publish(msg)
 
 
-def main(argv: List[str] = sys.argv[1:]) -> None:
+def main(argv: list[str] = sys.argv[1:]) -> None:
     parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
     parser.add_argument(
         '--reliable', dest='reliable', action='store_true',
diff --git a/demo_nodes_py/test/test_mypy.py b/demo_nodes_py/test/test_mypy.py
index afc6a332c..8b1a09e35 100644
--- a/demo_nodes_py/test/test_mypy.py
+++ b/demo_nodes_py/test/test_mypy.py
@@ -17,5 +17,5 @@
 
 
 def test_mypy() -> None:
-    rc = main()
+    rc = main(argv=['--ament-strict'])
     assert rc == 0, 'Found code style errors / warnings'

From 40082a861306dcec51b6c65f76b2abe003bccc79 Mon Sep 17 00:00:00 2001
From: Jonathan Setiawan <jonathanrustam2@gmail.com>
Date: Sun, 22 Mar 2026 10:21:50 +0900
Subject: [PATCH 04/11] restore EOF newline, %r byte-safe logging, and
 attr-defined ignore

Signed-off-by: Jonathan Setiawan <jonathanrustam2@gmail.com>
---
 .../demo_nodes_py/logging/use_logger_service.py          | 4 ++--
 demo_nodes_py/demo_nodes_py/services/introspection.py    | 3 +--
 .../demo_nodes_py/topics/listener_serialized.py          | 9 ++++++---
 demo_nodes_py/test/test_mypy.py                          | 2 +-
 4 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/demo_nodes_py/demo_nodes_py/logging/use_logger_service.py b/demo_nodes_py/demo_nodes_py/logging/use_logger_service.py
index 4d331e6bf..dbe7482b2 100644
--- a/demo_nodes_py/demo_nodes_py/logging/use_logger_service.py
+++ b/demo_nodes_py/demo_nodes_py/logging/use_logger_service.py
@@ -106,7 +106,7 @@ def set_logger_level_on_remote_node(
         set_logger_level = LoggerLevel()
         set_logger_level.name = logger_name if logger_name else self._remote_node_name
         set_logger_level.level = logger_level
-        request.levels.append(set_logger_level)
+        request.levels.append(set_logger_level)  # type: ignore[attr-defined]
 
         future = self._logger_set_client.call_async(request)
         rclpy.spin_until_future_complete(self, future)
@@ -137,7 +137,7 @@ def get_logger_level_on_remote_node(
 
         ret_results = future.result()
         if not ret_results:
-            return [(False, None)]
+            return False, None
 
         return True, ret_results.levels[0].level
 
diff --git a/demo_nodes_py/demo_nodes_py/services/introspection.py b/demo_nodes_py/demo_nodes_py/services/introspection.py
index 59a9e72a8..252c8fdbf 100644
--- a/demo_nodes_py/demo_nodes_py/services/introspection.py
+++ b/demo_nodes_py/demo_nodes_py/services/introspection.py
@@ -26,8 +26,6 @@
 from rclpy.qos import qos_profile_system_default
 from rclpy.service_introspection import ServiceIntrospectionState
 from rclpy.task import Future
-from rclpy.timer import Timer
-
 
 # This demo program shows how to configure client and service introspection
 # on the fly, by hooking it up to a parameter.  This program consists of both
@@ -74,6 +72,7 @@
 # In either case, service introspection data can be seen by running:
 #   ros2 topic echo /add_two_ints/_service_event
 
+
 def check_parameter(
     parameter_list: list[Parameter], parameter_name: str
 ) -> SetParametersResult:
diff --git a/demo_nodes_py/demo_nodes_py/topics/listener_serialized.py b/demo_nodes_py/demo_nodes_py/topics/listener_serialized.py
index b929be023..09a551cbd 100644
--- a/demo_nodes_py/demo_nodes_py/topics/listener_serialized.py
+++ b/demo_nodes_py/demo_nodes_py/topics/listener_serialized.py
@@ -13,16 +13,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from ctypes import Union
+from typing import Union
 
 from example_interfaces.msg import String
-from typing import Union
 
 import rclpy
 from rclpy.executors import ExternalShutdownException
 from rclpy.node import Node
 
+
 class SerializedSubscriber(Node):
+
     def __init__(self) -> None:
         super().__init__('serialized_subscriber')
         self.subscription = self.create_subscription(
@@ -35,7 +36,8 @@ def __init__(self) -> None:
         # not example_interfaces.msg.String
 
     def listener_callback(self, msg: bytes) -> None:
-        self.get_logger().info('I heard: "%s"' % msg)
+        self.get_logger().info('I heard: "%r"' % msg)
+
 
 def main(args: Union[list[str], None] = None) -> None:
     try:
@@ -46,5 +48,6 @@ def main(args: Union[list[str], None] = None) -> None:
     except (KeyboardInterrupt, ExternalShutdownException):
         pass
 
+
 if __name__ == '__main__':
     main()
diff --git a/demo_nodes_py/test/test_mypy.py b/demo_nodes_py/test/test_mypy.py
index 8b1a09e35..afc6a332c 100644
--- a/demo_nodes_py/test/test_mypy.py
+++ b/demo_nodes_py/test/test_mypy.py
@@ -17,5 +17,5 @@
 
 
 def test_mypy() -> None:
-    rc = main(argv=['--ament-strict'])
+    rc = main()
     assert rc == 0, 'Found code style errors / warnings'

From 41cfe49502ebc32aa9e48c519a23349738cd8912 Mon Sep 17 00:00:00 2001
From: Jonathan Setiawan <jonathanrustam2@gmail.com>
Date: Wed, 8 Apr 2026 11:47:13 +0900
Subject: [PATCH 05/11] pass --ament-strict as list to avoid crash in test_mypy

Signed-off-by: Jonathan Setiawan <jonathanrustam2@gmail.com>
---
 demo_nodes_py/test/test_mypy.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/demo_nodes_py/test/test_mypy.py b/demo_nodes_py/test/test_mypy.py
index afc6a332c..8b1a09e35 100644
--- a/demo_nodes_py/test/test_mypy.py
+++ b/demo_nodes_py/test/test_mypy.py
@@ -17,5 +17,5 @@
 
 
 def test_mypy() -> None:
-    rc = main()
+    rc = main(argv=['--ament-strict'])
     assert rc == 0, 'Found code style errors / warnings'

From f917b2ef86986356fdcb67a1d14959138e01ad69 Mon Sep 17 00:00:00 2001
From: Jonathan Setiawan <jonathanrustam2@gmail.com>
Date: Wed, 15 Apr 2026 04:02:08 +0900
Subject: [PATCH 06/11] restore [type-arg] ignores for list[Parameter]

Signed-off-by: Jonathan Setiawan <jonathanrustam2@gmail.com>
---
 .../parameters/set_parameters_callback.py              |  8 ++++----
 demo_nodes_py/demo_nodes_py/services/introspection.py  | 10 +++++-----
 demo_nodes_py/test/test_mypy.py                        |  2 +-
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
index 64ca79ccc..f280f0659 100644
--- a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
+++ b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
@@ -42,8 +42,8 @@ def __init__(self) -> None:
         # setting another parameter from the callback is possible
         # we expect the callback to be called for param2
         def pre_set_parameter_callback(
-            parameter_list: list[Parameter],
-        ) -> list[Parameter]:
+            parameter_list: list[Parameter],  # type: ignore[type-arg]
+        ) -> list[Parameter]:  # type: ignore[type-arg]
             modified_parameters = parameter_list.copy()
             for param in parameter_list:
                 if param.name == 'param1':
@@ -53,7 +53,7 @@ def pre_set_parameter_callback(
 
         # validation callback
         def on_set_parameter_callback(
-            parameter_list: list[Parameter],
+            parameter_list: list[Parameter],  # type: ignore[type-arg]
         ) -> SetParametersResult:
             result = SetParametersResult()
             for param in parameter_list:
@@ -68,7 +68,7 @@ def on_set_parameter_callback(
 
         # can change internally tracked class attributes
         def post_set_parameter_callback(
-            parameter_list: list[Parameter],
+            parameter_list: list[Parameter],  # type: ignore[type-arg]
         ) -> None:
             for param in parameter_list:
                 if param.name == 'param1':
diff --git a/demo_nodes_py/demo_nodes_py/services/introspection.py b/demo_nodes_py/demo_nodes_py/services/introspection.py
index 252c8fdbf..796b804fd 100644
--- a/demo_nodes_py/demo_nodes_py/services/introspection.py
+++ b/demo_nodes_py/demo_nodes_py/services/introspection.py
@@ -74,7 +74,7 @@
 
 
 def check_parameter(
-    parameter_list: list[Parameter], parameter_name: str
+    parameter_list: list[Parameter], parameter_name: str  # type: ignore[type-arg]
 ) -> SetParametersResult:
     result = SetParametersResult()
     result.successful = True
@@ -98,12 +98,12 @@ def check_parameter(
 class IntrospectionClientNode(Node):
 
     def on_set_parameters_callback(
-        self, parameter_list: list[Parameter],
+        self, parameter_list: list[Parameter],  # type: ignore[type-arg]
     ) -> SetParametersResult:
         return check_parameter(parameter_list, 'client_configure_introspection')
 
     def on_post_set_parameters_callback(
-        self, parameter_list: list[Parameter],
+        self, parameter_list: list[Parameter],  # type: ignore[type-arg]
     ) -> None:
         for param in parameter_list:
             if param.name != 'client_configure_introspection':
@@ -162,12 +162,12 @@ def timer_callback(self) -> None:
 class IntrospectionServiceNode(Node):
 
     def on_set_parameters_callback(
-        self, parameter_list: list[Parameter],
+        self, parameter_list: list[Parameter],  # type: ignore[type-arg]
     ) -> SetParametersResult:
         return check_parameter(parameter_list, 'service_configure_introspection')
 
     def on_post_set_parameters_callback(
-        self, parameter_list: list[Parameter],
+        self, parameter_list: list[Parameter],  # type: ignore[type-arg]
     ) -> None:
         for param in parameter_list:
             if param.name != 'service_configure_introspection':
diff --git a/demo_nodes_py/test/test_mypy.py b/demo_nodes_py/test/test_mypy.py
index 8b1a09e35..afc6a332c 100644
--- a/demo_nodes_py/test/test_mypy.py
+++ b/demo_nodes_py/test/test_mypy.py
@@ -17,5 +17,5 @@
 
 
 def test_mypy() -> None:
-    rc = main(argv=['--ament-strict'])
+    rc = main()
     assert rc == 0, 'Found code style errors / warnings'

From 4d1d6a40b5ea2dcc3acf93847d761148f5c73f8c Mon Sep 17 00:00:00 2001
From: Jonathan Setiawan <jonathanrustam2@gmail.com>
Date: Thu, 16 Apr 2026 02:56:01 +0900
Subject: [PATCH 07/11] wrap lines for list[Parameter] ignores

Signed-off-by: Jonathan Setiawan <jonathanrustam2@gmail.com>
---
 .../parameters/set_parameters_callback.py      | 11 +++++++----
 .../demo_nodes_py/services/introspection.py    | 18 ++++++++++++------
 2 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
index f280f0659..4d157a023 100644
--- a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
+++ b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Union
+from typing import Any, Union
 
 from rcl_interfaces.msg import SetParametersResult
 
@@ -42,7 +42,8 @@ def __init__(self) -> None:
         # setting another parameter from the callback is possible
         # we expect the callback to be called for param2
         def pre_set_parameter_callback(
-            parameter_list: list[Parameter],  # type: ignore[type-arg]
+            parameter_list: \
+                list[Parameter],  # type: ignore[type-arg]
         ) -> list[Parameter]:  # type: ignore[type-arg]
             modified_parameters = parameter_list.copy()
             for param in parameter_list:
@@ -53,7 +54,8 @@ def pre_set_parameter_callback(
 
         # validation callback
         def on_set_parameter_callback(
-            parameter_list: list[Parameter],  # type: ignore[type-arg]
+            parameter_list: \
+                list[Parameter],  # type: ignore[type-arg]
         ) -> SetParametersResult:
             result = SetParametersResult()
             for param in parameter_list:
@@ -68,7 +70,8 @@ def on_set_parameter_callback(
 
         # can change internally tracked class attributes
         def post_set_parameter_callback(
-            parameter_list: list[Parameter],  # type: ignore[type-arg]
+            parameter_list: \
+                list[Parameter],  # type: ignore[type-arg]
         ) -> None:
             for param in parameter_list:
                 if param.name == 'param1':
diff --git a/demo_nodes_py/demo_nodes_py/services/introspection.py b/demo_nodes_py/demo_nodes_py/services/introspection.py
index 796b804fd..0c97c9ccb 100644
--- a/demo_nodes_py/demo_nodes_py/services/introspection.py
+++ b/demo_nodes_py/demo_nodes_py/services/introspection.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Union
+from typing import Any, Union
 
 from example_interfaces.srv import AddTwoInts
 from rcl_interfaces.msg import SetParametersResult
@@ -74,7 +74,9 @@
 
 
 def check_parameter(
-    parameter_list: list[Parameter], parameter_name: str  # type: ignore[type-arg]
+    parameter_list: \
+        list[Parameter],  # type: ignore[type-arg]
+    parameter_name: str
 ) -> SetParametersResult:
     result = SetParametersResult()
     result.successful = True
@@ -98,12 +100,14 @@ def check_parameter(
 class IntrospectionClientNode(Node):
 
     def on_set_parameters_callback(
-        self, parameter_list: list[Parameter],  # type: ignore[type-arg]
+        self, parameter_list: \
+            list[Parameter],  # type: ignore[type-arg]
     ) -> SetParametersResult:
         return check_parameter(parameter_list, 'client_configure_introspection')
 
     def on_post_set_parameters_callback(
-        self, parameter_list: list[Parameter],  # type: ignore[type-arg]
+        self, parameter_list: \
+            list[Parameter],  # type: ignore[type-arg]
     ) -> None:
         for param in parameter_list:
             if param.name != 'client_configure_introspection':
@@ -162,12 +166,14 @@ def timer_callback(self) -> None:
 class IntrospectionServiceNode(Node):
 
     def on_set_parameters_callback(
-        self, parameter_list: list[Parameter],  # type: ignore[type-arg]
+        self, parameter_list: \
+            list[Parameter],  # type: ignore[type-arg]
     ) -> SetParametersResult:
         return check_parameter(parameter_list, 'service_configure_introspection')
 
     def on_post_set_parameters_callback(
-        self, parameter_list: list[Parameter],  # type: ignore[type-arg]
+        self, parameter_list: \
+            list[Parameter],  # type: ignore[type-arg]
     ) -> None:
         for param in parameter_list:
             if param.name != 'service_configure_introspection':

From afa672fbd2e3f8f8db17d667de3ec2f41289abfe Mon Sep 17 00:00:00 2001
From: Jonathan Setiawan <jonathanrustam2@gmail.com>
Date: Thu, 16 Apr 2026 18:35:28 +0900
Subject: [PATCH 08/11] use ParamList type alias to fix flake8 indentation
 errors

Signed-off-by: Jonathan Setiawan <jonathanrustam2@gmail.com>
---
 .../parameters/set_parameters_callback.py     | 15 +++++++-------
 .../demo_nodes_py/services/introspection.py   | 20 ++++++++-----------
 2 files changed, 15 insertions(+), 20 deletions(-)

diff --git a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
index 4d157a023..fd0ac8532 100644
--- a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
+++ b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Any, Union
+from typing import Union
 
 from rcl_interfaces.msg import SetParametersResult
 
@@ -22,6 +22,8 @@
 from rclpy.node import Node
 from rclpy.parameter import Parameter
 
+ParamList = list[Parameter]  # type: ignore[type-arg]
+
 
 # Example usage: changing param1 successfully will result in setting of param2.
 # ros2 service call /set_parameters_callback/set_parameters rcl_interfaces/srv/SetParameters
@@ -42,9 +44,8 @@ def __init__(self) -> None:
         # setting another parameter from the callback is possible
         # we expect the callback to be called for param2
         def pre_set_parameter_callback(
-            parameter_list: \
-                list[Parameter],  # type: ignore[type-arg]
-        ) -> list[Parameter]:  # type: ignore[type-arg]
+            parameter_list: ParamList,
+        ) -> ParamList:
             modified_parameters = parameter_list.copy()
             for param in parameter_list:
                 if param.name == 'param1':
@@ -54,8 +55,7 @@ def pre_set_parameter_callback(
 
         # validation callback
         def on_set_parameter_callback(
-            parameter_list: \
-                list[Parameter],  # type: ignore[type-arg]
+            parameter_list: ParamList,
         ) -> SetParametersResult:
             result = SetParametersResult()
             for param in parameter_list:
@@ -70,8 +70,7 @@ def on_set_parameter_callback(
 
         # can change internally tracked class attributes
         def post_set_parameter_callback(
-            parameter_list: \
-                list[Parameter],  # type: ignore[type-arg]
+            parameter_list: ParamList,
         ) -> None:
             for param in parameter_list:
                 if param.name == 'param1':
diff --git a/demo_nodes_py/demo_nodes_py/services/introspection.py b/demo_nodes_py/demo_nodes_py/services/introspection.py
index 0c97c9ccb..6ce94a341 100644
--- a/demo_nodes_py/demo_nodes_py/services/introspection.py
+++ b/demo_nodes_py/demo_nodes_py/services/introspection.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Any, Union
+from typing import Union
 
 from example_interfaces.srv import AddTwoInts
 from rcl_interfaces.msg import SetParametersResult
@@ -27,6 +27,8 @@
 from rclpy.service_introspection import ServiceIntrospectionState
 from rclpy.task import Future
 
+ParamList = list[Parameter]  # type: ignore[type-arg]
+
 # This demo program shows how to configure client and service introspection
 # on the fly, by hooking it up to a parameter.  This program consists of both
 # a client node (IntrospectionClientNode) and a service node (IntrospectionServiceNode).
@@ -74,9 +76,7 @@
 
 
 def check_parameter(
-    parameter_list: \
-        list[Parameter],  # type: ignore[type-arg]
-    parameter_name: str
+    parameter_list: ParamList, parameter_name: str
 ) -> SetParametersResult:
     result = SetParametersResult()
     result.successful = True
@@ -100,14 +100,12 @@ def check_parameter(
 class IntrospectionClientNode(Node):
 
     def on_set_parameters_callback(
-        self, parameter_list: \
-            list[Parameter],  # type: ignore[type-arg]
+        self, parameter_list: ParamList,
     ) -> SetParametersResult:
         return check_parameter(parameter_list, 'client_configure_introspection')
 
     def on_post_set_parameters_callback(
-        self, parameter_list: \
-            list[Parameter],  # type: ignore[type-arg]
+        self, parameter_list: ParamList,
     ) -> None:
         for param in parameter_list:
             if param.name != 'client_configure_introspection':
@@ -166,14 +164,12 @@ def timer_callback(self) -> None:
 class IntrospectionServiceNode(Node):
 
     def on_set_parameters_callback(
-        self, parameter_list: \
-            list[Parameter],  # type: ignore[type-arg]
+        self, parameter_list: ParamList,
     ) -> SetParametersResult:
         return check_parameter(parameter_list, 'service_configure_introspection')
 
     def on_post_set_parameters_callback(
-        self, parameter_list: \
-            list[Parameter],  # type: ignore[type-arg]
+        self, parameter_list: ParamList,
     ) -> None:
         for param in parameter_list:
             if param.name != 'service_configure_introspection':

From 873fa6b157a609c2a51090bda942ea9d835f4c17 Mon Sep 17 00:00:00 2001
From: Jonathan Setiawan <jonathanrustam2@gmail.com>
Date: Fri, 17 Apr 2026 06:19:09 +0900
Subject: [PATCH 09/11] remove formatting tags and re-apply line wraps

Signed-off-by: Jonathan Setiawan <jonathanrustam2@gmail.com>
---
 .../parameters/set_parameters_callback.py     | 12 ++++++-----
 .../demo_nodes_py/services/introspection.py   | 21 +++++++++++++------
 2 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
index fd0ac8532..0c7c149e4 100644
--- a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
+++ b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
@@ -22,7 +22,6 @@
 from rclpy.node import Node
 from rclpy.parameter import Parameter
 
-ParamList = list[Parameter]  # type: ignore[type-arg]
 
 
 # Example usage: changing param1 successfully will result in setting of param2.
@@ -44,8 +43,9 @@ def __init__(self) -> None:
         # setting another parameter from the callback is possible
         # we expect the callback to be called for param2
         def pre_set_parameter_callback(
-            parameter_list: ParamList,
-        ) -> ParamList:
+            parameter_list:
+                list[Parameter],  # type: ignore[type-arg]
+        ) -> list[Parameter]:  # type: ignore[type-arg]
             modified_parameters = parameter_list.copy()
             for param in parameter_list:
                 if param.name == 'param1':
@@ -55,7 +55,8 @@ def pre_set_parameter_callback(
 
         # validation callback
         def on_set_parameter_callback(
-            parameter_list: ParamList,
+            parameter_list:
+                list[Parameter],  # type: ignore[type-arg]
         ) -> SetParametersResult:
             result = SetParametersResult()
             for param in parameter_list:
@@ -70,7 +71,8 @@ def on_set_parameter_callback(
 
         # can change internally tracked class attributes
         def post_set_parameter_callback(
-            parameter_list: ParamList,
+            parameter_list:
+                list[Parameter],  # type: ignore[type-arg]
         ) -> None:
             for param in parameter_list:
                 if param.name == 'param1':
diff --git a/demo_nodes_py/demo_nodes_py/services/introspection.py b/demo_nodes_py/demo_nodes_py/services/introspection.py
index 6ce94a341..8380c8a19 100644
--- a/demo_nodes_py/demo_nodes_py/services/introspection.py
+++ b/demo_nodes_py/demo_nodes_py/services/introspection.py
@@ -27,7 +27,6 @@
 from rclpy.service_introspection import ServiceIntrospectionState
 from rclpy.task import Future
 
-ParamList = list[Parameter]  # type: ignore[type-arg]
 
 # This demo program shows how to configure client and service introspection
 # on the fly, by hooking it up to a parameter.  This program consists of both
@@ -76,7 +75,9 @@
 
 
 def check_parameter(
-    parameter_list: ParamList, parameter_name: str
+    parameter_list:
+        list[Parameter],  # type: ignore[type-arg]
+    parameter_name: str
 ) -> SetParametersResult:
     result = SetParametersResult()
     result.successful = True
@@ -100,12 +101,16 @@ def check_parameter(
 class IntrospectionClientNode(Node):
 
     def on_set_parameters_callback(
-        self, parameter_list: ParamList,
+        self,
+        parameter_list:
+            list[Parameter],  # type: ignore[type-arg]
     ) -> SetParametersResult:
         return check_parameter(parameter_list, 'client_configure_introspection')
 
     def on_post_set_parameters_callback(
-        self, parameter_list: ParamList,
+        self,
+        parameter_list:
+            list[Parameter],  # type: ignore[type-arg]
     ) -> None:
         for param in parameter_list:
             if param.name != 'client_configure_introspection':
@@ -164,12 +169,16 @@ def timer_callback(self) -> None:
 class IntrospectionServiceNode(Node):
 
     def on_set_parameters_callback(
-        self, parameter_list: ParamList,
+        self,
+        parameter_list:
+            list[Parameter],  # type: ignore[type-arg]
     ) -> SetParametersResult:
         return check_parameter(parameter_list, 'service_configure_introspection')
 
     def on_post_set_parameters_callback(
-        self, parameter_list: ParamList,
+        self,
+        parameter_list:
+            list[Parameter],  # type: ignore[type-arg]
     ) -> None:
         for param in parameter_list:
             if param.name != 'service_configure_introspection':

From 6be6865b0b2e897d6bbec9d384f20aabcb1bd67e Mon Sep 17 00:00:00 2001
From: Jonathan Setiawan <jonathanrustam2@gmail.com>
Date: Fri, 17 Apr 2026 08:23:39 +0900
Subject: [PATCH 10/11] fix hanging indentation and format type ignores

Signed-off-by: Jonathan Setiawan <jonathanrustam2@gmail.com>
---
 .../parameters/set_parameters_callback.py         |  9 +++------
 .../demo_nodes_py/services/introspection.py       | 15 +++++----------
 2 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
index 0c7c149e4..e3aa2c6dd 100644
--- a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
+++ b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
@@ -43,8 +43,7 @@ def __init__(self) -> None:
         # setting another parameter from the callback is possible
         # we expect the callback to be called for param2
         def pre_set_parameter_callback(
-            parameter_list:
-                list[Parameter],  # type: ignore[type-arg]
+            parameter_list: list[Parameter],  # type: ignore[type-arg]
         ) -> list[Parameter]:  # type: ignore[type-arg]
             modified_parameters = parameter_list.copy()
             for param in parameter_list:
@@ -55,8 +54,7 @@ def pre_set_parameter_callback(
 
         # validation callback
         def on_set_parameter_callback(
-            parameter_list:
-                list[Parameter],  # type: ignore[type-arg]
+            parameter_list: list[Parameter],  # type: ignore[type-arg]
         ) -> SetParametersResult:
             result = SetParametersResult()
             for param in parameter_list:
@@ -71,8 +69,7 @@ def on_set_parameter_callback(
 
         # can change internally tracked class attributes
         def post_set_parameter_callback(
-            parameter_list:
-                list[Parameter],  # type: ignore[type-arg]
+            parameter_list: list[Parameter],  # type: ignore[type-arg]
         ) -> None:
             for param in parameter_list:
                 if param.name == 'param1':
diff --git a/demo_nodes_py/demo_nodes_py/services/introspection.py b/demo_nodes_py/demo_nodes_py/services/introspection.py
index 8380c8a19..a7ddb2321 100644
--- a/demo_nodes_py/demo_nodes_py/services/introspection.py
+++ b/demo_nodes_py/demo_nodes_py/services/introspection.py
@@ -75,8 +75,7 @@
 
 
 def check_parameter(
-    parameter_list:
-        list[Parameter],  # type: ignore[type-arg]
+    parameter_list: list[Parameter],  # type: ignore[type-arg]
     parameter_name: str
 ) -> SetParametersResult:
     result = SetParametersResult()
@@ -102,15 +101,13 @@ class IntrospectionClientNode(Node):
 
     def on_set_parameters_callback(
         self,
-        parameter_list:
-            list[Parameter],  # type: ignore[type-arg]
+        parameter_list: list[Parameter],  # type: ignore[type-arg]
     ) -> SetParametersResult:
         return check_parameter(parameter_list, 'client_configure_introspection')
 
     def on_post_set_parameters_callback(
         self,
-        parameter_list:
-            list[Parameter],  # type: ignore[type-arg]
+        parameter_list: list[Parameter],  # type: ignore[type-arg]
     ) -> None:
         for param in parameter_list:
             if param.name != 'client_configure_introspection':
@@ -170,15 +167,13 @@ class IntrospectionServiceNode(Node):
 
     def on_set_parameters_callback(
         self,
-        parameter_list:
-            list[Parameter],  # type: ignore[type-arg]
+        parameter_list: list[Parameter],  # type: ignore[type-arg]
     ) -> SetParametersResult:
         return check_parameter(parameter_list, 'service_configure_introspection')
 
     def on_post_set_parameters_callback(
         self,
-        parameter_list:
-            list[Parameter],  # type: ignore[type-arg]
+        parameter_list: list[Parameter],  # type: ignore[type-arg]
     ) -> None:
         for param in parameter_list:
             if param.name != 'service_configure_introspection':

From 6fc60a66c937925fe2da8450fe95b4576d515b38 Mon Sep 17 00:00:00 2001
From: Jonathan Setiawan <jonathanrustam2@gmail.com>
Date: Fri, 17 Apr 2026 09:41:03 +0900
Subject: [PATCH 11/11] fix spacing

Signed-off-by: Jonathan Setiawan <jonathanrustam2@gmail.com>
---
 .../demo_nodes_py/parameters/set_parameters_callback.py        | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
index e3aa2c6dd..8e83bef37 100644
--- a/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
+++ b/demo_nodes_py/demo_nodes_py/parameters/set_parameters_callback.py
@@ -23,13 +23,14 @@
 from rclpy.parameter import Parameter
 
 
-
 # Example usage: changing param1 successfully will result in setting of param2.
 # ros2 service call /set_parameters_callback/set_parameters rcl_interfaces/srv/SetParameters
 #       "{parameters: [{name: "param1", value: {type: 3, double_value: 1.0}}]}"
 
 # node for demonstrating correct usage of pre_set, on_set
 # and post_set parameter callbacks
+
+
 class SetParametersCallback(Node):
 
     def __init__(self) -> None: