Fix _consume_object_or_array on unbalanced brackets in JSON strings (#621)

Co-authored-by: Andrea Aquino <[email protected]>

Author: andryak

pydantic_settings/sources/providers/cli.py

@@ -450,8 +450,13 @@ def _consume_comma(self, item: str, merged_list: list[str], is_last_consumed_a_v
     def _consume_object_or_array(self, item: str, merged_list: list[str]) -> str:
         count = 1
         close_delim = '}' if item.startswith('{') else ']'
+        in_str = False
         for consumed in range(1, len(item)):
-            if item[consumed] in ('{', '['):
+            if item[consumed] == '"' and item[consumed - 1] != '\\':
+                in_str = not in_str
+            elif in_str:
+                continue
+            elif item[consumed] in ('{', '['):
                 count += 1
             elif item[consumed] in ('}', ']'):
                 count -= 1

tests/test_source_cli.py

@@ -2452,6 +2452,40 @@ class Root(BaseModel):
         )
 
 
+def test_cli_with_unbalanced_brackets_in_json_string():
+    class StrToStrDictOptions(BaseSettings):
+        nested: dict[str, str]
+
+    assert CliApp.run(StrToStrDictOptions, cli_args=['--nested={"test": "{"}']).model_dump() == {
+        'nested': {'test': '{'}
+    }
+    assert CliApp.run(StrToStrDictOptions, cli_args=['--nested={"test": "}"}']).model_dump() == {
+        'nested': {'test': '}'}
+    }
+    assert CliApp.run(StrToStrDictOptions, cli_args=['--nested={"test": "["}']).model_dump() == {
+        'nested': {'test': '['}
+    }
+    assert CliApp.run(StrToStrDictOptions, cli_args=['--nested={"test": "]"}']).model_dump() == {
+        'nested': {'test': ']'}
+    }
+
+    class StrToListDictOptions(BaseSettings):
+        nested: dict[str, list[str]]
+
+    assert CliApp.run(StrToListDictOptions, cli_args=['--nested={"test": ["{"]}']).model_dump() == {
+        'nested': {'test': ['{']}
+    }
+    assert CliApp.run(StrToListDictOptions, cli_args=['--nested={"test": ["}"]}']).model_dump() == {
+        'nested': {'test': ['}']}
+    }
+    assert CliApp.run(StrToListDictOptions, cli_args=['--nested={"test": ["["]}']).model_dump() == {
+        'nested': {'test': ['[']}
+    }
+    assert CliApp.run(StrToListDictOptions, cli_args=['--nested={"test": ["]"]}']).model_dump() == {
+        'nested': {'test': [']']}
+    }
+
+
 def test_cli_json_optional_default():
     class Nested(BaseModel):
         foo: int = 1