feat: add pytest for load_states_and_record_video function with video…

… recording validation

tests/test_load_states_and_record_video.py

@@ -0,0 +1,43 @@
+"""pytest for load_states_and_record_video.py"""
+
+import pytest
+import datetime
+from robot_sf.render.playback_recording import load_states_and_record_video
+from robot_sf.render.sim_view import MOVIEPY_AVAILABLE
+from pathlib import Path
+
+
+@pytest.mark.skipif(
+    not MOVIEPY_AVAILABLE, reason="MoviePy/ffmpeg not available for video recording"
+)
+def test_load_states_and_record_video(delete_video: bool = True):
+    """Test loading simulation states and recording them as video.
+
+    Args:
+        delete_video: Whether to delete the video file after test. Default True.
+    """
+    # Create recordings directory if it doesn't exist
+    recordings_dir = Path("recordings")
+    recordings_dir.mkdir(exist_ok=True)
+
+    # create a unique video name
+    video_name = "playback_test_" + datetime.datetime.now().strftime("%Y-%m-%d_%H-%M-%S") + ".mp4"
+
+    output_path = recordings_dir / video_name
+
+    try:
+        load_states_and_record_video(
+            "test_pygame/recordings/2024-06-04_08-39-59.pkl", str(output_path)
+        )
+
+        assert output_path.exists(), "Video file was not created"
+        assert output_path.stat().st_size > 0, "Video file is empty"
+    finally:
+        # Clean up
+        if output_path.exists() and delete_video:
+            output_path.unlink()
+
+
+
+if __name__ == "__main__":
+    test_load_states_and_record_video(delete_video=False)