TST: add to_datetime of NaT values with utc=True

Co-authored-by: André Elimelek de Weber (andrekwr) <[email protected]>
Co-authored-by: Henry Rocha (HenryRocha) <[email protected]>

Author: 3 people

pandas/tests/tools/test_to_datetime.py

@@ -7,6 +7,7 @@
     timedelta,
 )
 from decimal import Decimal
+from functools import partial
 import locale
 
 from dateutil.parser import parse
@@ -1014,6 +1015,36 @@ def test_convert_object_to_datetime_with_cache(
         )
         tm.assert_series_equal(result_series, expected_series)
 
+    @pytest.mark.parametrize("cache", [True, False])
+    @pytest.mark.parametrize(
+        "constructor",
+        (
+            partial(Series, dtype="object"),
+            list,
+            np.array,
+        ),
+    )
+    @pytest.mark.parametrize(
+        "datetimelikes,expected_values",
+        (
+            (
+                (datetime(3000, 1, 1, 0, 0, 0, 0, pytz.UTC),) * (start_caching_at + 1),
+                (NaT,) * (start_caching_at + 1),
+            ),
+        ),
+    )
+    def test_convert_object_to_datetime_nat_utc(
+        self, cache, datetimelikes, expected_values, constructor
+    ):
+        # GH#43732
+        res = constructor(datetimelikes)
+        result_series = Series(to_datetime(res, errors="coerce", cache=cache, utc=True))
+        expected_series = Series(
+            expected_values,
+            dtype="datetime64[ns, UTC]",
+        )
+        tm.assert_series_equal(result_series, expected_series)
+
     @pytest.mark.parametrize(
         "date, format",
         [