test: added test for _datacopied

tests/test_for_utils/test_banded_linalg.py

@@ -6,21 +6,78 @@
 
 ### Imports ###
 
+from typing import List, Union
+
 import numpy as np
 import pytest
 from scipy.linalg import solve_banded as scipy_solve_banded
 
 from chemotools.utils.banded_linalg import (
+    _datacopied,
     conv_upper_chol_banded_to_lu_banded_storage,
     lu_banded,
     lu_solve_banded,
     slogdet_lu_banded,
 )
 from tests.test_for_utils.utils_funcs import get_banded_slogdet
 
+### Constants ###
+
+_ARRAY_TO_VIEW: np.ndarray = np.array([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
+_VIEW = _ARRAY_TO_VIEW[::]
+
 ### Test Suite ###
 
 
+@pytest.mark.parametrize(
+    "arr, original, expected",
+    [
+        (  # Number 0 Different arrays
+            np.array([1, 2, 3]),
+            np.array([1, 2, 3]),
+            True,
+        ),
+        (  # Number 1 Array and list
+            np.array([1, 2, 3]),
+            [1, 2, 3],
+            True,
+        ),
+        (  # Number 2 Different data types
+            np.array([1, 2, 3]),
+            np.array([1, 2, 3], dtype=np.float64),
+            True,
+        ),
+        (  # Number 3 Different view and array
+            _ARRAY_TO_VIEW[0:3],
+            np.array([1, 2, 3]),
+            False,
+        ),
+        (  # Number 4 Same array
+            _ARRAY_TO_VIEW,
+            _ARRAY_TO_VIEW,
+            False,
+        ),
+        (  # Number 5 Same view and array
+            _VIEW,
+            _ARRAY_TO_VIEW,
+            False,
+        ),
+    ],
+)
+def test_datacopied(
+    arr: np.ndarray,
+    original: Union[np.ndarray, List],
+    expected: bool,
+) -> None:
+    """
+    Tests the function that checks if a NumPy array has been copied from another array
+    or list.
+
+    """
+
+    assert _datacopied(arr, original) == expected
+
+
 @pytest.mark.parametrize("with_finite_check", [True, False])
 @pytest.mark.parametrize("overwrite_b", [True, False])
 @pytest.mark.parametrize("n_rhs", [0, 1, 2])