TST: add date range test for reindex case from GH-32740 (#33265)

* add test on date range timezone reindex

* undo

* fix

* move code to datetime test

* import timedelta

* adding assertion the np array results

* comply to coding standard

* update

* update

* assert_numpy_array_equal

* comply black format

* format checking

* white space

* bleck

Author: BenjaminLiuPenrose

pandas/tests/indexes/datetimes/test_datetime.py

@@ -1,4 +1,4 @@
-from datetime import date
+from datetime import date, timedelta
 
 import dateutil
 import numpy as np
@@ -44,6 +44,45 @@ def test_reindex_preserves_tz_if_target_is_empty_list_or_array(self):
         assert str(index.reindex([])[0].tz) == "US/Eastern"
         assert str(index.reindex(np.array([]))[0].tz) == "US/Eastern"
 
+    def test_reindex_with_same_tz(self):
+        # GH 32740
+        rng_a = date_range("2010-01-01", "2010-01-02", periods=24, tz="utc")
+        rng_b = date_range("2010-01-01", "2010-01-02", periods=23, tz="utc")
+        result1, result2 = rng_a.reindex(
+            rng_b, method="nearest", tolerance=timedelta(seconds=20)
+        )
+        expected_list1 = [
+            "2010-01-01 00:00:00",
+            "2010-01-01 01:05:27.272727272",
+            "2010-01-01 02:10:54.545454545",
+            "2010-01-01 03:16:21.818181818",
+            "2010-01-01 04:21:49.090909090",
+            "2010-01-01 05:27:16.363636363",
+            "2010-01-01 06:32:43.636363636",
+            "2010-01-01 07:38:10.909090909",
+            "2010-01-01 08:43:38.181818181",
+            "2010-01-01 09:49:05.454545454",
+            "2010-01-01 10:54:32.727272727",
+            "2010-01-01 12:00:00",
+            "2010-01-01 13:05:27.272727272",
+            "2010-01-01 14:10:54.545454545",
+            "2010-01-01 15:16:21.818181818",
+            "2010-01-01 16:21:49.090909090",
+            "2010-01-01 17:27:16.363636363",
+            "2010-01-01 18:32:43.636363636",
+            "2010-01-01 19:38:10.909090909",
+            "2010-01-01 20:43:38.181818181",
+            "2010-01-01 21:49:05.454545454",
+            "2010-01-01 22:54:32.727272727",
+            "2010-01-02 00:00:00",
+        ]
+        expected1 = DatetimeIndex(
+            expected_list1, dtype="datetime64[ns, UTC]", freq=None,
+        )
+        expected2 = np.array([0] + [-1] * 21 + [23], dtype=np.int64,)
+        tm.assert_index_equal(result1, expected1)
+        tm.assert_numpy_array_equal(result2, expected2)
+
     def test_time_loc(self):  # GH8667
         from datetime import time
         from pandas._libs.index import _SIZE_CUTOFF