chore: import upstream snapshot with attribution

tests/test_validation.py

@@ -0,0 +1,29 @@
+# coding: utf-8
+
+from cleanlab.internal import validation
+import numpy as np
+import pandas as pd
+import pytest
+
+
+@pytest.mark.parametrize("y_list", [["a", "b", "a"], [0, 1, 2]])
+@pytest.mark.parametrize("format", [list, np.array, pd.Series, pd.DataFrame])
+def test_labels_to_array_return_types(y_list, format):
+    y = format(y_list)
+    labels = validation.labels_to_array(y)
+    assert isinstance(labels, np.ndarray)
+
+
+@pytest.mark.parametrize("y_list", [["a", "b", "a"], [0, 1, 2]])
+@pytest.mark.parametrize("format", [list, np.array, pd.Series])
+def test_labels_to_array_return_values(y_list, format):
+    y = format(y_list)
+    labels = validation.labels_to_array(y)
+    assert np.array_equal(y, labels)
+
+
+def test_label_to_array_raises_error():
+    # Pandas DataFrame should have only one column
+    y = pd.DataFrame({"a": [0, 1], "b": [2, 3]})
+    with pytest.raises(ValueError):
+        validation.labels_to_array(y)