Reverted WaitForTopics utility usage

launch_testing/launch_testing_examples/launch_testing_examples/check_msgs_launch_test.py

@@ -12,15 +12,18 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from threading import Event
+from threading import Thread
 import unittest
 
 import launch
 import launch.actions
 import launch_ros.actions
 import launch_testing.actions
 import launch_testing.markers
-from launch_testing_ros import WaitForTopics
 import pytest
+import rclpy
+from rclpy.node import Node
 from std_msgs.msg import String
 
 
@@ -39,6 +42,33 @@ def generate_test_description():
 
 class TestFixture(unittest.TestCase):
 
-    def test_check_if_msgs_published(self):
-        with WaitForTopics([('chatter', String)], timeout=5.0):
-            print('Topic received messages !')
+    def test_check_if_msgs_published(self, proc_output):
+        rclpy.init()
+        node = DummyNode('test_node')
+        node.start_subscriber()
+        msgs_received_flag = node.msg_event_object.wait(timeout=5.0)
+        assert msgs_received_flag, 'Did not receive msgs !'
+        rclpy.shutdown()
+
+
+class DummyNode(Node):
+
+    def __init__(self, name='test_node'):
+        super().__init__(name)
+        self.msg_event_object = Event()
+
+    def start_subscriber(self):
+        # Create a subscriber
+        self.subscription = self.create_subscription(
+            String,
+            'chatter',
+            self.subscriber_callback,
+            10
+        )
+
+        # Add a spin thread
+        self.ros_spin_thread = Thread(target=lambda node: rclpy.spin(node), args=(self,))
+        self.ros_spin_thread.start()
+
+    def subscriber_callback(self, data):
+        self.msg_event_object.set()