fix forward_ref_context not always being set

introspection/__init__.py

@@ -2,7 +2,7 @@
 New and improved introspection functions
 """
 
-__version__ = "1.9.6"
+__version__ = "1.9.7"
 
 from .parameter import *
 from .signature_ import *

introspection/parameter.py

@@ -1,6 +1,6 @@
 import inspect
-from typing import *
-from typing_extensions import Self
+import typing as t
+import typing_extensions as te
 
 from ._utils import PARAM_EMPTY
 from .types import ForwardRefContext
@@ -45,9 +45,9 @@ def __init__(
         self,
         name: str,
         kind: inspect._ParameterKind = inspect.Parameter.POSITIONAL_OR_KEYWORD,
-        default: Any = PARAM_EMPTY,
-        annotation: Any = PARAM_EMPTY,
-        forward_ref_context: Optional[ForwardRefContext] = None,
+        default: t.Any = PARAM_EMPTY,
+        annotation: t.Any = PARAM_EMPTY,
+        forward_ref_context: t.Optional[ForwardRefContext] = None,
     ):
         """
         :param name: The parameter's name
@@ -66,7 +66,7 @@ def __init__(
         self.forward_ref_context = forward_ref_context
 
     @classmethod
-    def from_parameter(cls, parameter: inspect.Parameter) -> Self:
+    def from_parameter(cls, parameter: inspect.Parameter) -> te.Self:
         """
         Creates a new :class:`Parameter` instance from an :class:`inspect.Parameter` instance.
 
@@ -75,12 +75,22 @@ def from_parameter(cls, parameter: inspect.Parameter) -> Self:
         """
         if isinstance(parameter, cls):
             return parameter
+        else:
+            return cls._from_inspect_parameter(parameter)
 
+    @classmethod
+    def _from_inspect_parameter(
+        cls,
+        parameter: inspect.Parameter,
+        *,
+        forward_ref_context: t.Optional[ForwardRefContext] = None,
+    ) -> te.Self:
         return cls(
             parameter.name,
             kind=parameter.kind,
             default=parameter.default,
             annotation=parameter.annotation,
+            forward_ref_context=forward_ref_context,
         )
 
     @property

introspection/signature_.py

@@ -113,9 +113,25 @@ def from_signature(
         """
         if isinstance(signature, cls):
             return signature
+        else:
+            return cls._from_inspect_signature(signature)
 
-        params = [Parameter.from_parameter(param) for param in signature.parameters.values()]
-        return cls(params, return_annotation=signature.return_annotation)
+    @classmethod
+    def _from_inspect_signature(
+        cls,
+        signature: inspect.Signature,
+        *,
+        forward_ref_context: t.Optional[ForwardRefContext] = None,
+    ) -> te.Self:
+        params = [
+            Parameter._from_inspect_parameter(param, forward_ref_context=forward_ref_context)
+            for param in signature.parameters.values()
+        ]
+        return cls(
+            params,
+            return_annotation=signature.return_annotation,
+            forward_ref_context=forward_ref_context,
+        )
 
     @classmethod
     def from_callable(  # type: ignore[incompatible-override]
@@ -212,7 +228,10 @@ def recurse(callable_: t.Callable) -> te.Self:
             except AttributeError:
                 pass
             else:
-                return cls.from_signature(sig)
+                if isinstance(sig, cls):
+                    return sig
+
+                return cls._from_inspect_signature(sig, forward_ref_context=callable_.__module__)
 
             # Are we even supposed to unwrap? If not, abort
             if not follow_wrapped:

introspection/typing/type_info.py

@@ -52,8 +52,8 @@ def __init__(
 
         self.annotations = tuple(annotations)
         self.type: Type_ = to_python(resolved_type, strict=False)
+        self.forward_ref_context = forward_ref_context
         self._arguments = args
-        self._context = forward_ref_context
 
     @cached_property
     def parameters(self) -> t.Optional[t.Tuple[TypeParameter, ...]]:

tests/test_signature.py

@@ -16,6 +16,7 @@ def foo(a, b=3) -> str:
         return ""
 
     sig = Signature.from_callable(foo)
+    assert sig.forward_ref_context == __name__
     assert sig.return_annotation is str
     assert len(sig.parameters) == 2
     assert list(sig.parameters) == ["a", "b"]
@@ -27,6 +28,7 @@ def foo(a, b=3) -> str:
 
 def test_get_int_signature():
     sig = Signature.from_callable(int)
+    assert sig.forward_ref_context in (None, "builtins")
     assert sig.return_annotation is int
     assert len(sig.parameters) == 2
     assert list(sig.parameters) == ["x", "base"]
@@ -38,6 +40,7 @@ def test_get_int_signature():
 
 def test_get_float_signature():
     sig = Signature.from_callable(float)
+    assert sig.forward_ref_context in (None, "builtins")
     assert sig.return_annotation is float
     assert len(sig.parameters) == 1
     assert list(sig.parameters) == ["x"]
@@ -47,6 +50,7 @@ def test_get_float_signature():
 
 def test_get_bool_signature():
     sig = Signature.from_callable(bool)
+    assert sig.forward_ref_context in (None, "builtins")
     assert sig.return_annotation is bool
     assert len(sig.parameters) == 1
     assert list(sig.parameters) == ["x"]
@@ -82,6 +86,7 @@ class MyDataClass:
 
     sig = Signature.from_callable(MyDataClass)
     assert list(sig.parameters) == ["foo"]
+    assert sig.forward_ref_context == __name__
 
 
 def test_get_abstract_class_signature():
@@ -95,6 +100,7 @@ def func(self):
 
     sig = Signature.from_callable(MyAbstractClass)
     assert list(sig.parameters) == ["foo"]
+    assert sig.forward_ref_context == __name__
 
 
 def test_constructor_descriptors():
@@ -162,6 +168,20 @@ def foo(a=5) -> str:
     assert s is sig
 
 
+def test_cached_signature():
+    def foo(a=5) -> str:
+        return "bar"
+
+    # Create and cache an `inspect.Signature`
+    foo.__signature__ = inspect.signature(foo)  # type: ignore
+
+    # Now, when we create a `Signature` object, make sure that metadata such as
+    # `forward_ref_context` is still available
+    sig = Signature.from_callable(foo)
+    assert sig.forward_ref_context == __name__
+    assert sig.parameters["a"].forward_ref_context == __name__
+
+
 BUILTIN_CALLABLES = {
     name: obj
     for name, obj in vars(builtins).items()
@@ -289,6 +309,7 @@ def __init__(self, init):
 
     sig = Signature.from_callable(Cls)
     assert list(sig.parameters) == ["init"]
+    assert sig.forward_ref_context == __name__
 
 
 def test_class_signature_with_no_constructor():
@@ -313,6 +334,7 @@ def __init__(self, init):
 
     sig = Signature.from_callable(Cls)
     assert list(sig.parameters) == ["meta"]
+    assert sig.forward_ref_context == __name__
 
 
 def test_skip_metaclass_signature():
@@ -327,6 +349,7 @@ def __init__(self, foo):
 
     sig = Signature.from_callable(Cls)
     assert list(sig.parameters) == ["foo"]
+    assert sig.forward_ref_context == __name__
 
 
 def test_mark_on_decorated_function():
@@ -350,6 +373,7 @@ def __init__(self, foo):
 
     sig = Signature.from_callable(Cls)
     assert list(sig.parameters) == ["foo"]
+    assert sig.forward_ref_context == __name__
 
 
 def test_partial():