added tests

Author: DeaMariaLeon

sklearn/compose/tests/test_column_transformer.py

@@ -1647,12 +1647,33 @@ def test_sk_visual_block_remainder_col_names_pandas():
     assert visual_block.name_details == (["col1"], ["col2"])
 
 
-def test_sk_visual_block_without_remainder():
+def test_sk_visual_block_full_transform():
+    """Check that visual_block doesn't return remainder when it has no columns
+    Non-regression test - https://github.com/scikit-learn/scikit-learn/issues/33513
+    """
     ct = ColumnTransformer([("norm1", Normalizer(), [0, 1])], remainder="passthrough")
     X = np.array([[0, 4], [3, 3]])
     ct.fit(X)
     visual_block = ct._sk_visual_block_()
     assert visual_block.names == ("norm1",)
+    assert visual_block.name_details == ([0, 1],)
+    assert isinstance(visual_block.estimators[0], Normalizer)
+
+
+def test_sk_visual_block_remainder_with_preprocessor():
+    """Check that visual_block doesn't cut the remainder if it is a transformer
+    Non-regression test - https://github.com/scikit-learn/scikit-learn/issues/33513
+    """
+    ct = ColumnTransformer(
+        [("norm1", Normalizer(), [0, 1])], remainder=StandardScaler()
+    )
+    X = np.array([[0, 4, 3], [3, 3, 3]])
+    ct.fit(X)
+    visual_block = ct._sk_visual_block_()
+    assert visual_block.names == ("norm1", "remainder")
+    assert visual_block.name_details == ([0, 1], [2])
+    assert isinstance(visual_block.estimators[0], Normalizer)
+    assert isinstance(visual_block.estimators[1], StandardScaler)
 
 
 @pytest.mark.parametrize("explicit_colname", ["first", "second", 0, 1])