TST: category isin on frame (#34363)

Author: vampypandya

pandas/tests/frame/methods/test_isin.py

@@ -189,3 +189,18 @@ def test_isin_empty_datetimelike(self):
         tm.assert_frame_equal(result, expected)
         result = df1_td.isin(df3)
         tm.assert_frame_equal(result, expected)
+
+    @pytest.mark.parametrize(
+        "values",
+        [
+            pd.DataFrame({"a": [1, 2, 3]}, dtype="category"),
+            pd.Series([1, 2, 3], dtype="category"),
+        ],
+    )
+    def test_isin_category_frame(self, values):
+        # GH#34256
+        df = pd.DataFrame({"a": [1, 2, 3], "b": [4, 5, 6]})
+        expected = DataFrame({"a": [True, True, True], "b": [False, False, False]})
+
+        result = df.isin(values)
+        tm.assert_frame_equal(result, expected)