Add ros_arguments option to Node action (#249)

Signed-off-by: Christophe Bedard <[email protected]>

Author: christophebedard

launch_ros/launch_ros/actions/node.py

@@ -125,6 +125,7 @@ def __init__(
         exec_name: Optional[SomeSubstitutionsType] = None,
         parameters: Optional[SomeParameters] = None,
         remappings: Optional[SomeRemapRules] = None,
+        ros_arguments: Optional[Iterable[SomeSubstitutionsType]] = None,
         arguments: Optional[Iterable[SomeSubstitutionsType]] = None,
         **kwargs
     ) -> None:
@@ -180,6 +181,9 @@ def __init__(
         wildcard namespace (`/**`) and other specific parameter declarations
         may overwrite it.
 
+        Using `ros_arguments` is equivalent to using `arguments` with a
+        prepended '--ros-args' item.
+
         :param: executable the name of the executable to find if a package
             is provided or otherwise a path to the executable to run.
         :param: package the package in which the node executable can be found
@@ -191,13 +195,15 @@ def __init__(
             or dictionaries of parameters.
         :param: remappings ordered list of 'to' and 'from' string pairs to be
             passed to the node as ROS remapping rules
+        :param: ros_arguments list of ROS arguments for the node
         :param: arguments list of extra arguments for the node
         """
         if package is not None:
             cmd = [ExecutableInPackage(package=package, executable=executable)]
         else:
             cmd = [executable]
         cmd += [] if arguments is None else arguments
+        cmd += [] if ros_arguments is None else ['--ros-args'] + ros_arguments
         # Reserve space for ros specific arguments.
         # The substitutions will get expanded when the action is executed.
         cmd += ['--ros-args']  # Prepend ros specific arguments with --ros-args flag
@@ -218,6 +224,7 @@ def __init__(
         self.__node_namespace = namespace
         self.__parameters = [] if parameters is None else normalized_params
         self.__remappings = [] if remappings is None else list(normalize_remap_rules(remappings))
+        self.__ros_arguments = ros_arguments
         self.__arguments = arguments
 
         self.__expanded_node_name = self.UNSPECIFIED_NODE_NAME

test_launch_ros/test/test_launch_ros/actions/test_node.py

@@ -47,11 +47,12 @@ def _assert_launch_no_errors(self, actions):
         ls.include_launch_description(ld)
         assert 0 == ls.run()
 
-    def _create_node(self, *, parameters=None, remappings=None):
+    def _create_node(self, *, parameters=None, remappings=None, ros_arguments=None):
         return launch_ros.actions.Node(
             package='demo_nodes_py', executable='talker_qos', output='screen',
             name='my_node', namespace='my_ns',
             exec_name='my_node_process',
+            ros_arguments=ros_arguments,
             arguments=['--number_of_cycles', '1'],
             parameters=parameters,
             remappings=remappings,
@@ -92,6 +93,13 @@ def test_launch_node_with_remappings(self):
         for i in range(2):
             assert expanded_remappings[i] == ('chatter', 'new_chatter')
 
+    def test_launch_node_with_ros_arguments(self):
+        node_action = self._create_node(ros_arguments=['--log-level', 'debug'])
+        self._assert_launch_no_errors([node_action])
+
+        cmd_string = ' '.join(node_action.process_details['cmd'])
+        assert '--ros-args --log-level debug' in cmd_string
+
     def test_launch_required_node(self):
         # This node will never exit on its own, it'll keep publishing forever.
         long_running_node = launch_ros.actions.Node(