expand test for demonstration purposes

Author: Robert Schmidtke

pandas/tests/tslibs/test_array_to_datetime.py

@@ -272,15 +272,21 @@ def test_to_datetime_barely_out_of_bounds():
         tslib.array_to_datetime(arr)
 
 
-def test_to_datetime_barely_inside_bounds():
+@pytest.mark.parametrize(
+    "timestamp",
+    [
+        # Close enough to bounds that scaling micros to nanos overflows
+        # but adding nanos would result in an in-bounds datetime.
+        "1677-09-21T00:12:43.145224193",
+        "1677-09-21T00:12:43.145224999",
+        # this always worked
+        "1677-09-21T00:12:43.145225000",
+    ],
+)
+def test_to_datetime_barely_inside_bounds(timestamp):
     # see gh-57150
-    #
-    # Close enough to bounds that scaling micros to nanos overflows
-    # but adding nanos would result in an in-bounds datetime.
-    arr = np.array(["1677-09-21T00:12:43.145224193"], dtype=object)
-    result, _ = tslib.array_to_datetime(arr)
-    expected = ["1677-09-21T00:12:43.145224193"]
-    tm.assert_numpy_array_equal(result, np.array(expected, dtype="M8[ns]"))
+    result, _ = tslib.array_to_datetime(np.array([timestamp], dtype=object))
+    tm.assert_numpy_array_equal(result, np.array([timestamp], dtype="M8[ns]"))
 
 
 class SubDatetime(datetime):