TST: Add test for operations on DataFrame with Interval CategoricalIndex

Author: another-green

pandas/tests/indexing/test_categorical.py

@@ -758,3 +758,23 @@ def test_map_with_dict_or_series(self):
         output = cur_index.map(mapper)
         # Order of categories in output can be different
         tm.assert_index_equal(expected, output)
+
+    def test_operations_with_interval_categories_index(self):
+        ind = pd.CategoricalIndex(pd.interval_range(start=0.0, end=2.0))
+        df = pd.DataFrame([[1, 2]], columns=ind)
+        # __add__
+        result = df + 100
+        expected = pd.DataFrame([[101, 102]], columns=ind)
+        tm.assert_frame_equal(result, expected)
+        # __substract__
+        result = df - 100
+        expected = pd.DataFrame([[-99, -98]], columns=ind)
+        tm.assert_frame_equal(result, expected)
+        # __multiply__
+        result = df * 100
+        expected = pd.DataFrame([[100, 200]], columns=ind)
+        tm.assert_frame_equal(result, expected)
+        # __divide__
+        result = df / 100
+        expected = pd.DataFrame([[0.01, 0.02]], columns=ind)
+        tm.assert_frame_equal(result, expected)