[utils] `traverse_obj`: Always return list when branching (#5170)

Fixes #5162
Authored by: Grub4K

1 files changed, 23 insertions, 4 deletions

diff --git a/test/test_utils.py b/test/test_utils.py
index 69313564a..6f3f6cb91 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -1890,6 +1890,7 @@ Line 1
                 {'index': 2},
                 {'index': 3},
             ),
+            'dict': {},
         }
 
         # Test base functionality
@@ -1926,11 +1927,15 @@ Line 1
 
         # Test alternative paths
         self.assertEqual(traverse_obj(_TEST_DATA, 'fail', 'str'), 'str',
-                         msg='multiple `path_list` should be treated as alternative paths')
+                         msg='multiple `paths` should be treated as alternative paths')
         self.assertEqual(traverse_obj(_TEST_DATA, 'str', 100), 'str',
                          msg='alternatives should exit early')
         self.assertEqual(traverse_obj(_TEST_DATA, 'fail', 'fail'), None,
                          msg='alternatives should return `default` if exhausted')
+        self.assertEqual(traverse_obj(_TEST_DATA, (..., 'fail'), 100), 100,
+                         msg='alternatives should track their own branching return')
+        self.assertEqual(traverse_obj(_TEST_DATA, ('dict', ...), ('data', ...)), list(_TEST_DATA['data']),
+                         msg='alternatives on empty objects should search further')
 
         # Test branch and path nesting
         self.assertEqual(traverse_obj(_TEST_DATA, ('urls', (3, 0), 'url')), ['https://www.example.com/0'],
@@ -1963,8 +1968,16 @@ Line 1
         self.assertEqual(traverse_obj(_TEST_DATA, {0: ('urls', ((1, ('fail', 'url')), (0, 'url')))}),
                          {0: ['https://www.example.com/1', 'https://www.example.com/0']},
                          msg='tripple nesting in dict path should be treated as branches')
-        self.assertEqual(traverse_obj({}, {0: 1}, default=...), {0: ...},
-                         msg='do not remove `None` values when dict key')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: 'fail'}), {},
+                         msg='remove `None` values when dict key')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: 'fail'}, default=...), {0: ...},
+                         msg='do not remove `None` values if `default`')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: 'dict'}), {0: {}},
+                         msg='do not remove empty values when dict key')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: 'dict'}, default=...), {0: {}},
+                         msg='do not remove empty values when dict key and a default')
+        self.assertEqual(traverse_obj(_TEST_DATA, {0: ('dict', ...)}), {0: []},
+                         msg='if branch in dict key not successful, return `[]`')
 
         # Testing default parameter behavior
         _DEFAULT_DATA = {'None': None, 'int': 0, 'list': []}
@@ -1981,7 +1994,13 @@ Line 1
         self.assertEqual(traverse_obj(_DEFAULT_DATA, ('list', 10)), None,
                          msg='`IndexError` should result in `default`')
         self.assertEqual(traverse_obj(_DEFAULT_DATA, (..., 'fail'), default=1), 1,
-                         msg='if branched but not successfull return `default`, not `[]`')
+                         msg='if branched but not successful return `default` if defined, not `[]`')
+        self.assertEqual(traverse_obj(_DEFAULT_DATA, (..., 'fail'), default=None), None,
+                         msg='if branched but not successful return `default` even if `default` is `None`')
+        self.assertEqual(traverse_obj(_DEFAULT_DATA, (..., 'fail')), [],
+                         msg='if branched but not successful return `[]`, not `default`')
+        self.assertEqual(traverse_obj(_DEFAULT_DATA, ('list', ...)), [],
+                         msg='if branched but object is empty return `[]`, not `default`')
 
         # Testing expected_type behavior
         _EXPECTED_TYPE_DATA = {'str': 'str', 'int': 0}