TST: Add tests to ensure proper conversion of datetime64/timedelta64/timestamp/duration to and from pyarrow (#54356)

* add pyarrow conversion pytests

* make test match GH issue and move test to proper location

* fix naming of expected and result variables for assertion

* optimize test

* make test mirror GH #54191

* fix test logic

Author: Julian048

pandas/tests/frame/methods/test_convert_dtypes.py

@@ -167,3 +167,11 @@ def test_convert_dtypes_pyarrow_to_np_nullable(self):
         result = ser.convert_dtypes(dtype_backend="numpy_nullable")
         expected = pd.DataFrame(range(2), dtype="Int32")
         tm.assert_frame_equal(result, expected)
+
+    def test_convert_dtypes_pyarrow_timestamp(self):
+        # GH 54191
+        pytest.importorskip("pyarrow")
+        ser = pd.Series(pd.date_range("2020-01-01", "2020-01-02", freq="1min"))
+        expected = ser.astype("timestamp[ms][pyarrow]")
+        result = expected.convert_dtypes(dtype_backend="pyarrow")
+        tm.assert_series_equal(result, expected)