chore: implemented test video function

If there is no qi session, the webcam of the device is used to send video.

test/unit/test_video_sender.py

@@ -97,3 +97,120 @@ def test_video_receive_error(zmq_context, mocker):
     sender.video_rcv_loop(mock_video_service, "stream_name")
 
     send_socket.assert_not_called()
+
+def test_video_stream_camera_fail(zmq_context, mocker):
+    """
+    Test that the function logs an error and returns early if
+    the webcam cannot be opened.
+    """
+    _patch_basics(mocker)
+    
+    # Mock cv2 and logging
+    mock_cv2 = mocker.patch("robot_interface.endpoints.video_sender.cv2")
+    mock_logging = mocker.patch("robot_interface.endpoints.video_sender.logging")
+
+    # Setup the mock capture to fail isOpened()
+    mock_cap = mock.Mock()
+    mock_cap.isOpened.return_value = False
+    mock_cv2.VideoCapture.return_value = mock_cap
+
+    sender = VideoSender(zmq_context)
+    sender.test_video_stream()
+
+    # Assertions
+    mock_cv2.VideoCapture.assert_called_with(0)
+    
+    # Ensure the loop was never entered and cleanup didn't happen
+    assert not mock_cap.read.called
+    assert not mock_cap.release.called
+
+
+def test_video_stream_read_fail(zmq_context, mocker):
+    """
+    Test that the function logs a warning and continues the loop 
+    if a specific frame fails to read.
+    """
+    _patch_basics(mocker)
+    _patch_exit_event(mocker)  # Run loop exactly once
+
+    mock_cv2 = mocker.patch("robot_interface.endpoints.video_sender.cv2")
+    mock_logging = mocker.patch("robot_interface.endpoints.video_sender.logging")
+
+    # Setup capture to open successfully, but fail the read()
+    mock_cap = mock.Mock()
+    mock_cap.isOpened.return_value = True
+    # Return (False, None) simulating a failed frame read
+    mock_cap.read.return_value = (False, None)
+    mock_cv2.VideoCapture.return_value = mock_cap
+
+    sender = VideoSender(zmq_context)
+    # Mock the socket to ensure nothing is sent
+    sender.socket = mock.Mock()
+
+    sender.test_video_stream()
+    
+    # Ensure we skipped the processing steps
+    assert not mock_cv2.resize.called
+    assert not sender.socket.send.called
+    
+    # Ensure cleanup happened at the end
+    mock_cap.release.assert_called_once()
+
+
+def test_video_stream_success(zmq_context, mocker):
+    """
+    Test the happy path: Frame read -> Resize -> Encode -> Send.
+    """
+    _patch_basics(mocker)
+    _patch_exit_event(mocker)  # Run loop exactly once
+
+    mock_cv2 = mocker.patch("robot_interface.endpoints.video_sender.cv2")
+    
+    # Setup constants usually found in cv2
+    mock_cv2.IMWRITE_JPEG_QUALITY = 1
+    mock_cv2.INTER_AREA = 2
+
+    # Setup capture to work perfectly
+    mock_cap = mock.Mock()
+    mock_cap.isOpened.return_value = True
+    fake_frame = "original_frame_data"
+    mock_cap.read.return_value = (True, fake_frame)
+    mock_cv2.VideoCapture.return_value = mock_cap
+
+    # Setup Resize and Encode
+    mock_cv2.resize.return_value = "small_frame_data"
+    
+    # Mock buffer behavior
+    mock_buffer = mock.Mock()
+    mock_buffer.tobytes.return_value = b"encoded_bytes"
+    # imencode returns (retval, buffer)
+    mock_cv2.imencode.return_value = (True, mock_buffer)
+
+    sender = VideoSender(zmq_context)
+    sender.socket = mock.Mock()
+
+    sender.test_video_stream()
+
+    # Assertions
+    # 1. Check waitKey (the 1ms delay)
+    mock_cv2.waitKey.assert_called_with(1)
+
+    # 2. Check Resize logic
+    mock_cv2.resize.assert_called_with(
+        fake_frame, 
+        (320, 240), 
+        interpolation=mock_cv2.INTER_AREA
+    )
+
+    # 3. Check Encode logic
+    mock_cv2.imencode.assert_called_with(
+        '.jpg', 
+        "small_frame_data", 
+        [mock_cv2.IMWRITE_JPEG_QUALITY, 70]
+    )
+
+    # 4. Check Socket Send
+    sender.socket.send.assert_called_with(b"encoded_bytes")
+
+    # 5. Check Cleanup
+    mock_cap.release.assert_called_once()