[ros2param] Provide tests for ros2param verbs

ros2param/package.xml

@@ -21,6 +21,7 @@
   <test_depend>ament_pep257</test_depend>
   <test_depend>ament_xmllint</test_depend>
   <test_depend>python3-pytest</test_depend>
+  <test_depend>ros_testing</test_depend>
 
   <export>
     <build_type>ament_python</build_type>

ros2param/test/fixtures/param_node.py

@@ -0,0 +1,56 @@
+# Copyright 2019 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.
+
+import sys
+
+from rcl_interfaces.msg import ParameterDescriptor
+import rclpy
+from rclpy.node import Node
+
+
+class ParamNode(Node):
+
+    def __init__(self):
+        super().__init__('param_node')
+        self.declare_parameter('bool_param', True, ParameterDescriptor())
+        self.declare_parameter('int_param', 42, ParameterDescriptor())
+        self.declare_parameter('double_param', 1.23, ParameterDescriptor())
+        self.declare_parameter('str_param', 'Hello World', ParameterDescriptor())
+        self.declare_parameter('int_array', [1, 2, 3], ParameterDescriptor())
+        self.declare_parameter('double_array', [1.0, 2.0, 3.0], ParameterDescriptor())
+        self.declare_parameter('bool_array', [True, False, True], ParameterDescriptor())
+        self.declare_parameter('str_array', ['Hello', 'World'], ParameterDescriptor())
+        self.declare_parameter('byte_array', [b'p', b'v'], ParameterDescriptor())
+        self.declare_parameter('parameter_with_no_value', None, ParameterDescriptor())
+
+
+def main(args=None):
+    rclpy.init(args=args)
+
+    node = ParamNode()
+
+    try:
+        rclpy.spin(node)
+    except KeyboardInterrupt:
+        print('node stopped cleanly')
+    except BaseException:
+        print('exception in node:', file=sys.stderr)
+        raise
+    finally:
+        node.destroy_node()
+        rclpy.shutdown()
+
+
+if __name__ == '__main__':
+    main()