[utils] Introduce merge_dicts

1 files changed, 12 insertions, 0 deletions

diff --git a/test/test_utils.py b/test/test_utils.py
index 253a7fe17..14503ab53 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -42,6 +42,7 @@ from youtube_dl.utils import (
     is_html,
     js_to_json,
     limit_length,
+    merge_dicts,
     mimetype2ext,
     month_by_name,
     multipart_encode,
@@ -669,6 +670,17 @@ class TestUtil(unittest.TestCase):
             self.assertEqual(dict_get(d, ('b', 'c', key, )), None)
             self.assertEqual(dict_get(d, ('b', 'c', key, ), skip_false_values=False), false_value)
 
+    def test_merge_dicts(self):
+        self.assertEqual(merge_dicts({'a': 1}, {'b': 2}), {'a': 1, 'b': 2})
+        self.assertEqual(merge_dicts({'a': 1}, {'a': 2}), {'a': 1})
+        self.assertEqual(merge_dicts({'a': 1}, {'a': None}), {'a': 1})
+        self.assertEqual(merge_dicts({'a': 1}, {'a': ''}), {'a': 1})
+        self.assertEqual(merge_dicts({'a': 1}, {}), {'a': 1})
+        self.assertEqual(merge_dicts({'a': None}, {'a': 1}), {'a': 1})
+        self.assertEqual(merge_dicts({'a': ''}, {'a': 1}), {'a': ''})
+        self.assertEqual(merge_dicts({'a': ''}, {'a': 'abc'}), {'a': 'abc'})
+        self.assertEqual(merge_dicts({'a': None}, {'a': ''}, {'a': 'abc'}), {'a': 'abc'})
+
     def test_encode_compat_str(self):
         self.assertEqual(encode_compat_str(b'\xd1\x82\xd0\xb5\xd1\x81\xd1\x82', 'utf-8'), 'тест')
         self.assertEqual(encode_compat_str('тест', 'utf-8'), 'тест')