Allow merge_unique on lists when merge_enabled=True

dynaconf/utils/__init__.py

@@ -46,6 +46,12 @@ def object_merge(
         return new
 
     if isinstance(old, list) and isinstance(new, list):
+
+        # 726: allow local_merge to override global merge on lists
+        if "dynaconf_merge_unique" in new:
+            new.remove("dynaconf_merge_unique")
+            unique = True
+
         for item in old[::-1]:
             if unique and item in new:
                 continue

tests_functional/issues/726_unique_nested_list/app.py

@@ -0,0 +1,16 @@
+from __future__ import annotations
+
+from dynaconf import Dynaconf
+
+settings = Dynaconf(
+    envvar_prefix="ISSUE726",
+    settings_files=["defaults.yaml", "configuration.yaml"],
+    merge_enabled=True,
+)
+
+
+assert settings.config_key.nested_list == [
+    "item_a",
+    "item_b",
+    "item_c",
+], settings.config_key.nested_list

tests_functional/issues/726_unique_nested_list/configuration.yaml

@@ -0,0 +1,6 @@
+config_key:
+  nested_list:
+    - dynaconf_merge_unique
+    - item_a
+    - item_b
+    - item_c

tests_functional/issues/726_unique_nested_list/defaults.yaml

@@ -0,0 +1,4 @@
+config_key:
+  nested_list:
+    - item_a
+    - item_b