docs, fixes and test for nixtrack data wrapper

test/test_nixtrackio.py

@@ -0,0 +1,32 @@
+import pytest
+import etrack as et
+
+from IPython import embed
+
+dataset = "test/2022lepto01_converted_2024.03.27_0.mp4.nix"
+
+
+@pytest.fixture
+def nixtrack_data():
+    # Create a NixTrackData object with some test data
+    return et.NixtrackData(dataset)
+
+
+def test_basics(nixtrack_data):
+    assert nixtrack_data.filename == dataset
+    assert len(nixtrack_data.bodyparts) == 5
+    assert len(nixtrack_data.tracks) == 2
+    assert nixtrack_data.fps == 25
+
+
+def test_trackingdata(nixtrack_data):
+    with pytest.raises(ValueError):
+        nixtrack_data.track_data(bodypart="test")
+        nixtrack_data.track_data(track="fish")
+
+    assert nixtrack_data.track_data("center") is not None
+    assert nixtrack_data.track_data("center", "none") is not None
+
+
+if __name__ == "__main__":
+    pytest.main()