TST: concat(..., copy=False) with datetime tz-aware data raises ValueError (pandas-dev#33458)

Co-authored-by: Simon Hawkins <[email protected]>

Author: 2 people

pandas/tests/dtypes/test_concat.py

@@ -88,3 +88,14 @@ def test_concat_mismatched_categoricals_with_empty():
     result = _concat.concat_compat([ser1._values, ser2._values])
     expected = pd.concat([ser1, ser2])._values
     tm.assert_categorical_equal(result, expected)
+
+
+@pytest.mark.parametrize("copy", [True, False])
+def test_concat_single_dataframe_tz_aware(copy):
+    # https://github.com/pandas-dev/pandas/issues/25257
+    df = pd.DataFrame(
+        {"timestamp": [pd.Timestamp("2020-04-08 09:00:00.709949+0000", tz="UTC")]}
+    )
+    expected = df.copy()
+    result = pd.concat([df], copy=copy)
+    tm.assert_frame_equal(result, expected)