Fix handle type alias declared with type statement

Author: tselepakis

pydantic_settings/sources/utils.py

@@ -43,6 +43,10 @@ def parse_env_vars(
 def _annotation_is_complex(annotation: type[Any] | None, metadata: list[Any]) -> bool:
     # If the model is a root model, the root annotation should be used to
     # evaluate the complexity.
+    if annotation and (
+        typing_objects.is_typealiastype(annotation) or typing_objects.is_typealiastype(get_origin(annotation))
+    ):
+        annotation = annotation.__value__
     if annotation is not None and _lenient_issubclass(annotation, RootModel) and annotation is not RootModel:
         annotation = cast('type[RootModel[Any]]', annotation)
         root_annotation = annotation.model_fields['root'].annotation

pyproject.toml

@@ -143,6 +143,9 @@ pydocstyle = { convention = 'google' }
 [tool.ruff.format]
 quote-style = 'single'
 
+[tool.ruff.per-file-target-version]
+"tests/test_settings_py312.py" = "py312"
+
 [tool.mypy]
 python_version = '3.10'
 show_error_codes = true

tests/conftest.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import os
+import sys
 from pathlib import Path
 from typing import TYPE_CHECKING
 
@@ -99,3 +100,20 @@ def cli_test_env():
     yield setenv
 
     setenv.clear()
+
+
+def pytest_ignore_collect(collection_path: Path, config) -> bool:
+    """
+    Ignore collection of test files that contain syntax unsupported
+    by the current Python version.
+    """
+    py312_tests = {'test_settings_py312.py'}
+
+    if sys.version_info < (3, 12) and collection_path.name in py312_tests:
+        print(
+            f"\nSkipping collection of '{collection_path.name}' on Python "
+            f'{sys.version_info.major}.{sys.version_info.minor} due to syntax requirements.'
+        )
+        return True
+
+    return None

tests/test_settings_py312.py

@@ -0,0 +1,21 @@
+from typing import Annotated
+
+from annotated_types import MinLen
+
+from pydantic_settings import BaseSettings
+
+try:
+    import dotenv
+except ImportError:
+    dotenv = None
+
+
+def test_annotated_with_type(env):
+    type MinLenList = Annotated[list[str], MinLen(2)]
+
+    class AnnotatedComplexSettings(BaseSettings):
+        apples: MinLenList
+
+    env.set('apples', '["russet", "granny smith"]')
+    s = AnnotatedComplexSettings()
+    assert s.apples == ['russet', 'granny smith']