Handle forward references in Type typehints (#576)

---------

Co-authored-by: Mauricio Villegas <[email protected]>

CHANGELOG.rst

@@ -27,6 +27,9 @@ Fixed
 - Callable type with subclass return not showing the ``--*.help`` option (`#567
   <https://github.com/omni-us/jsonargparse/pull/567>`__).
 
+- Forward referenced types not compatible with `Type` typehint (`#576
+  <https://github.com/omni-us/jsonargparse/pull/576/>`__)
+
 Changed
 ^^^^^^^
 - Removed shtab experimental warning (`#561

jsonargparse/_postponed_annotations.py

@@ -229,6 +229,8 @@ def resolve_subtypes_forward_refs(typehint):
                             typehint_origin = Tuple
                         elif typehint_origin in mapping_origin_types:
                             typehint_origin = Dict
+                        elif typehint_origin == type:
+                            typehint_origin = Type
                     typehint = typehint_origin[tuple(subtypes)]
             except Exception as ex:
                 if logger:
@@ -240,6 +242,9 @@ def resolve_subtypes_forward_refs(typehint):
 
 def has_subtypes(typehint):
     typehint_origin = get_typehint_origin(typehint)
+    if typehint_origin is type and hasattr(typehint, "__args__"):
+        return True
+
     return (
         typehint_origin == Union
         or typehint_origin in sequence_origin_types
@@ -260,7 +265,6 @@ def get_types(obj: Any, logger: Optional[logging.Logger] = None) -> dict:
         types = get_type_hints(obj, global_vars)
     except Exception as ex1:
         types = ex1  # type: ignore[assignment]
-
     if isinstance(types, dict) and all(not type_requires_eval(t) for t in types.values()):
         return types
 

jsonargparse_tests/test_postponed_annotations.py

@@ -10,7 +10,11 @@
 
 from jsonargparse import Namespace
 from jsonargparse._parameter_resolvers import get_signature_parameters as get_params
-from jsonargparse._postponed_annotations import TypeCheckingVisitor, evaluate_postponed_annotations, get_types
+from jsonargparse._postponed_annotations import (
+    TypeCheckingVisitor,
+    evaluate_postponed_annotations,
+    get_types,
+)
 from jsonargparse.typing import Path_drw
 from jsonargparse_tests.conftest import capture_logs, source_unavailable
 
@@ -267,6 +271,17 @@ def test_get_types_type_checking_tuple():
     assert str(types["p1"]) == f"{tpl}[{__name__}.TypeCheckingClass1, {__name__}.TypeCheckingClass2]"
 
 
+def function_type_checking_type(p1: Type["TypeCheckingClass2"]):
+    return p1
+
+
+def test_get_types_type_checking_type():
+    types = get_types(function_type_checking_type)
+    assert list(types.keys()) == ["p1"]
+    tpl = "typing.Type" if sys.version_info < (3, 10) else "type"
+    assert str(types["p1"]) == f"{tpl}[{__name__}.TypeCheckingClass2]"
+
+
 def function_type_checking_dict(p1: Dict[str, Union[TypeCheckingClass1, "TypeCheckingClass2"]]):
     return p1