fix: Support simple return annotations

Issue #9: #9

Author: pawamoy

src/griffe_typingdoc/_static.py

@@ -196,6 +196,11 @@ def _returns_docs(func: Function, **kwargs: Any) -> DocstringSectionReturns | No
         "typing_extensions.Generator",
     }:
         return_annotation = annotation.slice.elements[2]  # type: ignore[attr-defined]
+    elif isinstance(annotation, ExprSubscript) and annotation.canonical_path in {
+        "typing.Annotated",
+        "typing_extensions.Annotated",
+    }:
+        return_annotation = annotation
 
     if return_annotation:
         if isinstance(return_annotation, ExprSubscript) and return_annotation.is_tuple:

tests/test_extension.py

@@ -7,9 +7,17 @@
 
 from griffe_typingdoc import TypingDocExtension
 
-typing_imports = "from typing import Annotated, Doc, Generator, Iterator, Name, NotRequired, Raises, TypedDict, Unpack, Warns"
+typing_imports = (
+    "from typing import Annotated, Doc, Generator, Iterator, Name, NotRequired, Raises, TypedDict, Unpack, Warns"
+)
 warning_imports = "from warnings import deprecated"
 
+# NOTE: Important! The value in calls to `Doc` will be parsed as a Name expression
+# if it is valid Python syntax for names. To make sure it is correctly parsed as a string,
+# it must contain invalid syntax for names, such as a dot at the end.
+# The alternative solution would be to add `from __future__ import annotations`
+# at the beginning of each temporary visited module.
+
 
 def test_extension_on_itself() -> None:
     """Load our own package using the extension, assert a parameters section is added to the parsed docstring."""
@@ -41,7 +49,6 @@ def test_parameter_doc() -> None:
         assert package["f"].docstring.parsed[1].value[0].description == "Hello."
 
 
-
 def test_other_parameter_doc() -> None:
     """Read documentation for other parameters, in unpack/typeddict annotations."""
     with temporary_visited_package(
@@ -133,3 +140,13 @@ def f() -> Generator[
         assert sections[2].value[1].description == "Second received."
         assert sections[3].value[0].description == "First returned."
         assert sections[3].value[1].description == "Second returned."
+
+
+def test_return_doc() -> None:
+    """Read documentation for return value."""
+    with temporary_visited_package(
+        "package",
+        modules={"__init__.py": f"{typing_imports}\ndef f() -> Annotated[int, Doc('Hello.')]: ..."},
+        extensions=Extensions(TypingDocExtension()),
+    ) as package:
+        assert package["f"].docstring.parsed[1].value[0].description == "Hello."