🐛 Fix evaluating stringified annotations in Python 3.9 and less (also from __future__ import annotations)

Author: sisp

pyproject.toml

@@ -35,7 +35,7 @@ classifiers = [
 ]
 dependencies = [
     "click >= 8.0.0",
-    "typing-extensions >= 3.7.4.3",
+    "typing-extensions >= 4.13.0",
 ]
 readme = "README.md"
 [project.urls]

tests/test_annotated.py

@@ -2,8 +2,6 @@
 from typer.testing import CliRunner
 from typing_extensions import Annotated
 
-from .utils import needs_py310
-
 runner = CliRunner()
 
 
@@ -23,7 +21,6 @@ def cmd(val: Annotated[int, typer.Argument()] = 0):
     assert "hello 42" in result.output
 
 
-@needs_py310
 def test_annotated_argument_in_string_type_with_default():
     app = typer.Typer()
 

typer/_inspect.py

@@ -0,0 +1,28 @@
+import inspect
+import sys
+
+if sys.version_info >= (3, 10):
+    from inspect import signature
+else:
+    from typing import Any
+
+    from typing_extensions import get_annotations
+
+    def signature(func, eval_str=False, **kwargs: Any):
+        sig = inspect.signature(func, **kwargs)
+        ann = get_annotations(
+            func,
+            globals=kwargs.get("globals"),
+            locals=kwargs.get("locals"),
+            eval_str=eval_str,
+        )
+        return sig.replace(
+            parameters=[
+                param.replace(annotation=ann.get(name, param.annotation))
+                for name, param in sig.parameters.items()
+            ],
+            return_annotation=ann.get("return", sig.return_annotation),
+        )
+
+
+__all__ = ["signature"]

typer/utils.py

@@ -1,8 +1,7 @@
-import inspect
-import sys
 from copy import copy
 from typing import Any, Callable, Dict, List, Tuple, Type, cast
 
+from ._inspect import signature as inspect_signature
 from ._typing import Annotated, get_args, get_origin, get_type_hints
 from .models import ArgumentInfo, OptionInfo, ParameterInfo, ParamMeta
 
@@ -105,12 +104,8 @@ def _split_annotation_from_typer_annotations(
 
 
 def get_params_from_function(func: Callable[..., Any]) -> Dict[str, ParamMeta]:
-    if sys.version_info >= (3, 10):
-        signature = inspect.signature(func, eval_str=True)
-    else:
-        signature = inspect.signature(func)
-
-    type_hints = get_type_hints(func)
+    signature = inspect_signature(func, eval_str=True)
+    type_hints = get_type_hints(func, include_extras=True)
     params = {}
     for param in signature.parameters.values():
         annotation, typer_annotations = _split_annotation_from_typer_annotations(