TST: Add tests string series min max (#45505)

Author: NumberPiOso

pandas/tests/series/test_reductions.py

@@ -9,6 +9,14 @@
 import pandas._testing as tm
 
 
+@pytest.mark.parametrize("operation, expected", [("min", "a"), ("max", "b")])
+def test_reductions_series_strings(operation, expected):
+    # GH#31746
+    ser = Series(["a", "b"], dtype="string")
+    res_operation_serie = getattr(ser, operation)()
+    assert res_operation_serie == expected
+
+
 @pytest.mark.parametrize("as_period", [True, False])
 def test_mode_extension_dtype(as_period):
     # GH#41927 preserve dt64tz dtype