Fix sphinx-doc#7567: autodoc: parametrized types are shown twice for …

…generic types

CHANGES

@@ -67,6 +67,7 @@ Bugs fixed
 
 * #6703: autodoc: incremental build does not work for imported objects
 * #7564: autodoc: annotations not to be shown for descriptors
+* #7567: autodoc: parametrized types are shown twice for generic types
 
 Testing
 --------

sphinx/util/typing.py

@@ -10,7 +10,7 @@
 
 import sys
 import typing
-from typing import Any, Callable, Dict, List, Tuple, TypeVar, Union
+from typing import Any, Callable, Dict, Generic, List, Tuple, TypeVar, Union
 
 from docutils import nodes
 from docutils.parsers.rst.states import Inliner
@@ -93,6 +93,9 @@ def _stringify_py37(annotation: Any) -> str:
             return stringify(annotation.__args__[0])
         elif annotation._special:
             return qualname
+        elif issubclass(annotation.__origin__, Generic):  # type: ignore
+            # subclasses of Generic already contains the types for elements in its name
+            return qualname
         else:
             args = ', '.join(stringify(a) for a in annotation.__args__)
             return '%s[%s]' % (qualname, args)

tests/test_util_typing.py

@@ -10,7 +10,7 @@
 
 import sys
 from numbers import Integral
-from typing import Any, Dict, List, TypeVar, Union, Callable, Tuple, Optional
+from typing import Any, Dict, Generic, List, TypeVar, Union, Callable, Tuple, Optional
 
 import pytest
 
@@ -94,6 +94,16 @@ def test_stringify_type_hints_typevars():
     assert stringify(List[T]) == "List[T]"
 
 
+def test_stringify_type_hints_Generic():
+    T = TypeVar('T')
+
+    class Foo(Generic[T]):
+        pass
+
+    expected = "test_util_typing.test_stringify_type_hints_Generic.<locals>.Foo[int]"
+    assert stringify(Foo[int]) == expected
+
+
 def test_stringify_type_hints_custom_class():
     assert stringify(MyClass1) == "test_util_typing.MyClass1"
     assert stringify(MyClass2) == "test_util_typing.<MyClass2>"