Adding tests for sorting of FP arrays with NaNs

dpctl/tests/test_usm_ndarray_sorting.py

@@ -14,6 +14,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import itertools
+
+import numpy as np
 import pytest
 
 import dpctl.tensor as dpt
@@ -211,3 +214,69 @@ def test_argsort_0d_array():
 
     x = dpt.asarray(1, dtype="i4")
     assert dpt.argsort(x) == 0
+
+
+@pytest.mark.parametrize(
+    "dtype",
+    [
+        "f2",
+        "f4",
+        "f8",
+    ],
+)
+def test_sort_real_fp_nan(dtype):
+    q = get_queue_or_skip()
+    skip_if_dtype_not_supported(dtype, q)
+
+    x = dpt.asarray(
+        [-0.0, 0.1, dpt.nan, 0.0, -0.1, dpt.nan, 0.2, -0.3], dtype=dtype
+    )
+    s = dpt.sort(x)
+
+    expected = dpt.asarray(
+        [-0.3, -0.1, -0.0, 0.0, 0.1, 0.2, dpt.nan, dpt.nan], dtype=dtype
+    )
+
+    assert dpt.allclose(s, expected, equal_nan=True)
+
+    s = dpt.sort(x, descending=True)
+
+    expected = dpt.asarray(
+        [dpt.nan, dpt.nan, 0.2, 0.1, -0.0, 0.0, -0.1, -0.3], dtype=dtype
+    )
+
+    assert dpt.allclose(s, expected, equal_nan=True)
+
+
+@pytest.mark.parametrize(
+    "dtype",
+    [
+        "c8",
+        "c16",
+    ],
+)
+def test_sort_complex_fp_nan(dtype):
+    q = get_queue_or_skip()
+    skip_if_dtype_not_supported(dtype, q)
+
+    rvs = [-0.0, 0.1, 0.0, 0.2, -0.3, dpt.nan]
+    ivs = [-0.0, 0.1, 0.0, 0.2, -0.3, dpt.nan]
+
+    cv = []
+    for rv in rvs:
+        for iv in ivs:
+            cv.append(complex(rv, iv))
+
+    inp = dpt.asarray(cv, dtype=dtype)
+    s = dpt.sort(inp)
+
+    expected = np.sort(dpt.asnumpy(inp))
+
+    assert np.allclose(dpt.asnumpy(s), expected, equal_nan=True)
+
+    for i, j in itertools.permutations(range(inp.shape[0]), 2):
+        r1 = dpt.asnumpy(dpt.sort(inp[dpt.asarray([i, j])]))
+        r2 = np.sort(dpt.asnumpy(inp[dpt.asarray([i, j])]))
+        assert np.array_equal(
+            r1.view(np.int64), r2.view(np.int64)
+        ), f"Failed for {i} and {j}"