Fix #9362: autodoc: AttributeError is raised for a subclass of Tuple[()]

CHANGES

@@ -88,6 +88,7 @@ Bugs fixed
   attribute not having any comment
 * #9364: autodoc: single element tuple on the default argument value is wrongly
   rendered
+* #9362: autodoc: AttributeError is raised on processing a subclass of Tuple[()]
 * #9317: html: Pushing left key causes visiting the next page at the first page
 * #9381: html: URL for html_favicon and html_log does not work
 * #9270: html theme : pyramid theme generates incorrect logo links

sphinx/util/typing.py

@@ -105,27 +105,30 @@ def restify(cls: Optional[Type]) -> str:
     """Convert python class to a reST reference."""
     from sphinx.util import inspect  # lazy loading
 
-    if cls is None or cls is NoneType:
-        return ':obj:`None`'
-    elif cls is Ellipsis:
-        return '...'
-    elif cls in INVALID_BUILTIN_CLASSES:
-        return ':class:`%s`' % INVALID_BUILTIN_CLASSES[cls]
-    elif inspect.isNewType(cls):
-        return ':class:`%s`' % cls.__name__
-    elif types_Union and isinstance(cls, types_Union):
-        if len(cls.__args__) > 1 and None in cls.__args__:
-            args = ' | '.join(restify(a) for a in cls.__args__ if a)
-            return 'Optional[%s]' % args
-        else:
-            return ' | '.join(restify(a) for a in cls.__args__)
-    elif cls.__module__ in ('__builtin__', 'builtins'):
-        return ':class:`%s`' % cls.__name__
-    else:
-        if sys.version_info >= (3, 7):  # py37+
-            return _restify_py37(cls)
+    try:
+        if cls is None or cls is NoneType:
+            return ':obj:`None`'
+        elif cls is Ellipsis:
+            return '...'
+        elif cls in INVALID_BUILTIN_CLASSES:
+            return ':class:`%s`' % INVALID_BUILTIN_CLASSES[cls]
+        elif inspect.isNewType(cls):
+            return ':class:`%s`' % cls.__name__
+        elif types_Union and isinstance(cls, types_Union):
+            if len(cls.__args__) > 1 and None in cls.__args__:
+                args = ' | '.join(restify(a) for a in cls.__args__ if a)
+                return 'Optional[%s]' % args
+            else:
+                return ' | '.join(restify(a) for a in cls.__args__)
+        elif cls.__module__ in ('__builtin__', 'builtins'):
+            return ':class:`%s`' % cls.__name__
         else:
-            return _restify_py36(cls)
+            if sys.version_info >= (3, 7):  # py37+
+                return _restify_py37(cls)
+            else:
+                return _restify_py36(cls)
+    except AttributeError:
+        return repr(cls)
 
 
 def _restify_py37(cls: Optional[Type]) -> str:

tests/test_util_typing.py

@@ -60,6 +60,7 @@ def test_restify_type_hints_containers():
     assert restify(Tuple[str, str, str]) == (":class:`~typing.Tuple`\\ "
                                              "[:class:`str`, :class:`str`, :class:`str`]")
     assert restify(Tuple[str, ...]) == ":class:`~typing.Tuple`\\ [:class:`str`, ...]"
+    assert restify(Tuple[()]) == ":class:`~typing.Tuple`\\ [()]"
     assert restify(List[Dict[str, Tuple]]) == (":class:`~typing.List`\\ "
                                                "[:class:`~typing.Dict`\\ "
                                                "[:class:`str`, :class:`~typing.Tuple`]]")
@@ -168,6 +169,7 @@ def test_stringify_type_hints_containers():
     assert stringify(Dict[str, float]) == "Dict[str, float]"
     assert stringify(Tuple[str, str, str]) == "Tuple[str, str, str]"
     assert stringify(Tuple[str, ...]) == "Tuple[str, ...]"
+    assert stringify(Tuple[()]) == "Tuple[()]"
     assert stringify(List[Dict[str, Tuple]]) == "List[Dict[str, Tuple]]"
     assert stringify(MyList[Tuple[int, int]]) == "tests.test_util_typing.MyList[Tuple[int, int]]"
     assert stringify(Generator[None, None, None]) == "Generator[None, None, None]"