TEST: Comprehensive consolidation of all test cases into parametrized test

Author: cloudboat

pandas/tests/indexes/multi/test_insert_level.py

@@ -36,6 +36,62 @@ class TestMultiIndexInsertLevel:
                 [("A", "middle", 1), ("B", "middle", 2), ("C", "middle", 3)],
                 ["level1", "custom_name", "level2"],
             ),
+            (
+                0,
+                "start",
+                None,
+                [("start", "A", 1), ("start", "B", 2), ("start", "C", 3)],
+                [None, "level1", "level2"],
+            ),
+            (
+                2,
+                "end",
+                None,
+                [("A", 1, "end"), ("B", 2, "end"), ("C", 3, "end")],
+                ["level1", "level2", None],
+            ),
+            (
+                1,
+                100,
+                None,
+                [("A", 100, 1), ("B", 100, 2), ("C", 100, 3)],
+                ["level1", None, "level2"],
+            ),
+            (
+                1,
+                1.5,
+                None,
+                [("A", 1.5, 1), ("B", 1.5, 2), ("C", 1.5, 3)],
+                ["level1", None, "level2"],
+            ),
+            (
+                1,
+                None,
+                None,
+                [("A", None, 1), ("B", None, 2), ("C", None, 3)],
+                ["level1", None, "level2"],
+            ),
+            (
+                1,
+                ["X", "Y", "Z"],
+                None,
+                [("A", "X", 1), ("B", "Y", 2), ("C", "Z", 3)],
+                ["level1", None, "level2"],
+            ),
+            (
+                0,
+                "",
+                "empty_string",
+                [("", "A", 1), ("", "B", 2), ("", "C", 3)],
+                ["empty_string", "level1", "level2"],
+            ),
+            (
+                1,
+                True,
+                None,
+                [("A", True, 1), ("B", True, 2), ("C", True, 3)],
+                ["level1", None, "level2"],
+            ),
         ],
     )
     def test_insert_level_basic(
@@ -49,27 +105,13 @@ def test_insert_level_basic(
         expected = pd.MultiIndex.from_tuples(expected_tuples, names=expected_names)
         tm.assert_index_equal(result, expected)
 
-    @pytest.mark.parametrize(
-        "position, value",
-        [
-            (0, "start"),
-            (2, "end"),
-        ],
-    )
-    def test_insert_level_edge_positions(self, position, value):
-        simple_idx = pd.MultiIndex.from_tuples(
-            [("A", 1), ("B", 2), ("C", 3)], names=["level1", "level2"]
-        )
-
-        result = simple_idx.insert_level(position, value)
-        assert result.nlevels == 3
-
     @pytest.mark.parametrize(
         "position, value, expected_error",
         [
             (5, "invalid", "position must be between"),
             (-1, "invalid", "position must be between"),
             (1, ["too", "few"], "Length of values must match"),
+            (3, "value", "position must be between"),
         ],
     )
     def test_insert_level_error_cases(self, position, value, expected_error):
@@ -80,18 +122,6 @@ def test_insert_level_error_cases(self, position, value, expected_error):
         with pytest.raises(ValueError, match=expected_error):
             simple_idx.insert_level(position, value)
 
-    @pytest.mark.parametrize(
-        "value",
-        [100, 1.5, None],
-    )
-    def test_insert_level_with_different_data_types(self, value):
-        simple_idx = pd.MultiIndex.from_tuples(
-            [("A", 1), ("B", 2), ("C", 3)], names=["level1", "level2"]
-        )
-
-        result = simple_idx.insert_level(1, value)
-        assert result.nlevels == 3
-
     def test_insert_level_preserves_original(self):
         simple_idx = pd.MultiIndex.from_tuples(
             [("A", 1), ("B", 2), ("C", 3)], names=["level1", "level2"]
@@ -106,18 +136,14 @@ def test_insert_level_empty_index(self):
         empty_idx = pd.MultiIndex.from_tuples([], names=["level1", "level2"])
 
         result = empty_idx.insert_level(0, [])
-        assert result.nlevels == 3
-        assert len(result) == 0
+        expected = pd.MultiIndex.from_tuples([], names=[None, "level1", "level2"])
+        tm.assert_index_equal(result, expected)
 
-    def test_insert_level_with_different_values(self):
-        simple_idx = pd.MultiIndex.from_tuples(
-            [("A", 1), ("B", 2), ("C", 3)], names=["level1", "level2"]
-        )
+    def test_insert_level_single_element(self):
+        single_idx = pd.MultiIndex.from_tuples([("A", 1)], names=["level1", "level2"])
 
-        new_values = ["X", "Y", "Z"]
-        result = simple_idx.insert_level(1, new_values)
+        result = single_idx.insert_level(1, "middle")
         expected = pd.MultiIndex.from_tuples(
-            [("A", "X", 1), ("B", "Y", 2), ("C", "Z", 3)],
-            names=["level1", None, "level2"],
+            [("A", "middle", 1)], names=["level1", None, "level2"]
         )
         tm.assert_index_equal(result, expected)