Fix #7023: autodoc: nested partial functions are not listed

CHANGES

@@ -51,6 +51,7 @@ Bugs fixed
 * #6559: Wrong node-ids are generated in glossary directive
 * #6986: apidoc: misdetects module name for .so file inside module
 * #6999: napoleon: fails to parse tilde in :exc: role
+* #7023: autodoc: nested partial functions are not listed
 
 Testing
 --------

sphinx/util/inspect.py

@@ -121,6 +121,17 @@ def isenumattribute(x: Any) -> bool:
     return isinstance(x, enum.Enum)
 
 
+def unpartial(obj: Any) -> Any:
+    """Get an original object from partial object.
+
+    This returns given object itself if not partial.
+    """
+    while ispartial(obj):
+        obj = obj.func
+
+    return obj
+
+
 def ispartial(obj: Any) -> bool:
     """Check if the object is partial."""
     return isinstance(obj, (partial, partialmethod))
@@ -197,24 +208,21 @@ def isattributedescriptor(obj: Any) -> bool:
 
 def isfunction(obj: Any) -> bool:
     """Check if the object is function."""
-    return inspect.isfunction(obj) or ispartial(obj) and inspect.isfunction(obj.func)
+    return inspect.isfunction(unpartial(obj))
 
 
 def isbuiltin(obj: Any) -> bool:
     """Check if the object is builtin."""
-    return inspect.isbuiltin(obj) or ispartial(obj) and inspect.isbuiltin(obj.func)
+    return inspect.isbuiltin(unpartial(obj))
 
 
 def iscoroutinefunction(obj: Any) -> bool:
     """Check if the object is coroutine-function."""
+    obj = unpartial(obj)
     if hasattr(obj, '__code__') and inspect.iscoroutinefunction(obj):
         # check obj.__code__ because iscoroutinefunction() crashes for custom method-like
         # objects (see https://github.com/sphinx-doc/sphinx/issues/6605)
         return True
-    elif (ispartial(obj) and hasattr(obj.func, '__code__') and
-          inspect.iscoroutinefunction(obj.func)):
-        # partialed
-        return True
     else:
         return False
 

tests/roots/test-ext-autodoc/target/partialfunction.py

@@ -1,11 +1,12 @@
 from functools import partial
 
 
-def func1():
+def func1(a, b, c):
     """docstring of func1"""
     pass
 
 
-func2 = partial(func1)
-func3 = partial(func1)
+func2 = partial(func1, 1)
+func3 = partial(func2, 2)
 func3.__doc__ = "docstring of func3"
+func4 = partial(func3, 3)

tests/test_autodoc.py

@@ -1241,19 +1241,25 @@ def test_partialfunction():
         '.. py:module:: target.partialfunction',
         '',
         '',
-        '.. py:function:: func1()',
+        '.. py:function:: func1(a, b, c)',
         '   :module: target.partialfunction',
         '',
         '   docstring of func1',
         '   ',
         '',
-        '.. py:function:: func2()',
+        '.. py:function:: func2(b, c)',
         '   :module: target.partialfunction',
         '',
         '   docstring of func1',
         '   ',
         '',
-        '.. py:function:: func3()',
+        '.. py:function:: func3(c)',
+        '   :module: target.partialfunction',
+        '',
+        '   docstring of func3',
+        '   ',
+        '',
+        '.. py:function:: func4()',
         '   :module: target.partialfunction',
         '',
         '   docstring of func3',

tests/test_util_inspect.py

@@ -511,3 +511,15 @@ def test_isproperty(app):
     assert inspect.isproperty(Base.meth) is False       # method of class
     assert inspect.isproperty(Base().meth) is False     # method of instance
     assert inspect.isproperty(func) is False            # function
+
+
+def test_unpartial():
+    def func1(a, b, c):
+        pass
+
+    func2 = functools.partial(func1, 1)
+    func2.__doc__ = "func2"
+    func3 = functools.partial(func2, 2)  # nested partial object
+
+    assert inspect.unpartial(func2) is func1
+    assert inspect.unpartial(func3) is func1