add camera unit test

src/camera/test/test_camera.py

@@ -0,0 +1,72 @@
+import os
+import sys
+import unittest
+import time
+
+import launch
+import launch_ros
+import launch_ros.actions
+import launch_testing.actions
+import pytest
+import rclpy
+
+from drone_services.srv import TakePicture
+
+@pytest.mark.rostest
+def generate_test_description():
+    file_path = os.path.dirname(__file__)
+    camera_node = launch_ros.actions.Node(
+        executable=sys.executable,
+        arguments=[os.path.join(file_path, '..', 'camera', 'camera.py')],
+        additional_env={'PYTHONUNBUFFERED': '1'}
+    )
+
+    return (
+        launch.LaunchDescription([
+            camera_node,
+            launch_testing.actions.ReadyToTest(),
+        ]),
+        {
+            'camera_node': camera_node,
+        }
+    )
+
+class CameraUnitTest(unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        rclpy.init()
+
+    @classmethod
+    def tearDownClass(cls):
+        rclpy.shutdown()
+    
+    def setUp(self):
+        self.node = rclpy.create_node('test_camera')
+        self.service_called = False
+
+    def tearDown(self):
+        self.node.destroy_node()
+
+    def service_call_callback(self,future):
+        self.assertIsNotNone(future.result())
+        self.assertEqual(future.result().filename, "/home/ubuntu/test_image.jpg")
+        self.assertTrue(os.path.exists("/home/ubuntu/test_image.jpg"))
+        self.service_called = True
+
+    def test_camera_save_image(self,camera_node,proc_output):
+        # call camera service
+        camera_client = self.node.create_client(TakePicture, '/drone/take_picture')
+        while not camera_client.wait_for_service(timeout_sec=1.0):
+            self.node.get_logger().info('camera service not available, waiting again...')
+        request = TakePicture.Request()
+        request.input_name = "/home/ubuntu/test_image.jpg"
+        try:
+            while True:
+                rclpy.spin_once(self.node,timeout_sec=0.1)
+                if not self.service_called:
+                    camera_client.call_async(request).add_done_callback(self.service_call_callback)
+                else:
+                    break
+        finally:
+            self.node.destroy_client(camera_client)