Fix stubs-only resolver incorrectly triggered when inspect.signature available leading to missing parameter defaults (#724)

Author: mauvilsa

CHANGELOG.rst

@@ -30,6 +30,9 @@ Fixed
   <https://github.com/omni-us/jsonargparse/pull/717>`__).
 - ``TypedDict`` values not validated when types are forward references (`#722
   <https://github.com/omni-us/jsonargparse/pull/722>`__).
+- Stubs-only resolver incorrectly triggered when ``inspect.signature`` available
+  leading to missing parameter defaults (`#724
+  <https://github.com/omni-us/jsonargparse/pull/724>`__).
 
 Changed
 ^^^^^^^

jsonargparse/_parameter_resolvers.py

@@ -1042,6 +1042,11 @@ def get_parameters_from_stubs(
     logger: logging.Logger,
 ) -> Optional[ParamList]:
     component, parent, _ = get_component_and_parent(function_or_class, method_or_property)
+    try:
+        inspect.signature(component)
+        return None
+    except Exception:
+        pass  # only from stubs if getting signature fails
     params = None
     resolver = get_stubs_resolver()
     stub_import = resolver.get_component_imported_info(component, parent)

jsonargparse/_stubs_resolver.py

@@ -4,7 +4,6 @@
 from contextlib import suppress
 from copy import deepcopy
 from importlib import import_module
-from pathlib import Path
 from typing import TYPE_CHECKING, Any, Dict, Optional, Tuple
 
 from ._optionals import import_typeshed_client, typeshed_client_support
@@ -105,9 +104,7 @@ def find(self, node: ast.AST, method_name: str) -> Optional[ast.FunctionDef]:
 def get_stubs_resolver():
     global stubs_resolver
     if not stubs_resolver:
-        search_path = [Path(p) for p in sys.path]
-        search_context = tc.get_search_context(search_path=search_path)
-        stubs_resolver = StubsResolver(search_context=search_context)
+        stubs_resolver = StubsResolver()
     return stubs_resolver
 
 
@@ -134,8 +131,8 @@ def get_source_module(path: str, component) -> tc.ModulePath:
 
 
 class StubsResolver(tc.Resolver):
-    def __init__(self, search_context=None) -> None:
-        super().__init__(search_context)
+    def __init__(self, **kwargs) -> None:
+        super().__init__(**kwargs)
         self._module_ast_cache: Dict[str, Optional[ast.AST]] = {}
         self._module_assigns_cache: Dict[str, Dict[str, ast.Assign]] = {}
         self._module_imports_cache: Dict[str, Dict[str, Tuple[Optional[str], str]]] = {}
@@ -144,8 +141,8 @@ def get_imported_info(self, path: str, component=None) -> Optional[tc.ImportedIn
         resolved = self.get_fully_qualified_name(path)
         imported_info = None
         if isinstance(resolved, tc.ImportedInfo):
-            resolved = resolved.info
-        if isinstance(resolved, tc.NameInfo):
+            imported_info = resolved
+        elif isinstance(resolved, tc.NameInfo):
             source_module = get_source_module(path, component)
             imported_info = tc.ImportedInfo(source_module=source_module, info=resolved)
         return imported_info

jsonargparse_tests/conftest.py

@@ -185,7 +185,7 @@ def capture_logs(logger: logging.Logger) -> Iterator[StringIO]:
 
 @contextmanager
 def source_unavailable():
-    with patch("inspect.getsource", side_effect=OSError("could not get source code")):
+    with patch("inspect.getsource", side_effect=OSError("mock source code not available")):
         yield
 
 

jsonargparse_tests/test_postponed_annotations.py

@@ -73,7 +73,7 @@ def test_get_types_pep604():
 def test_get_types_pep604_source_unavailable(logger):
     with source_unavailable(), pytest.raises(TypeError) as ctx, capture_logs(logger) as logs:
         get_types(function_pep604, logger)
-    ctx.match("could not get source code")
+    ctx.match("mock source code not available")
     assert "Failed to parse to source code" in logs.getvalue()
 
 

pyproject.toml

@@ -52,7 +52,7 @@ all = [
 signatures = [
     "jsonargparse[typing-extensions]",
     "docstring-parser>=0.15",
-    "typeshed-client>=2.1.0",
+    "typeshed-client>=2.3.0",
 ]
 jsonschema = [
     "jsonschema>=3.2.0",