TEST: cut() with nullable Int64 dtype (#51384)

Author: kkangs0226

pandas/tests/reshape/test_cut.py

@@ -744,3 +744,18 @@ def test_cut_bins_datetime_intervalindex():
     result = cut(Series([Timestamp("2022-02-26")]), bins=bins)
     expected = Categorical.from_codes([0], bins, ordered=True)
     tm.assert_categorical_equal(result.array, expected)
+
+
+def test_cut_with_nullable_int64():
+    # GH 30787
+    series = Series([0, 1, 2, 3, 4, pd.NA, 6, 7], dtype="Int64")
+    bins = [0, 2, 4, 6, 8]
+    intervals = IntervalIndex.from_breaks(bins)
+
+    expected = Series(
+        Categorical.from_codes([-1, 0, 0, 1, 1, -1, 2, 3], intervals, ordered=True)
+    )
+
+    result = cut(series, bins=bins)
+
+    tm.assert_series_equal(result, expected)