Fix sphinx-doc#904: autodoc: An instance attribute cause a crash of a…

…utofunction

So far, autofunction only checks the existence of the class variable.
As a result, it crashes with AttributeError if an instance variable is
specified.

This adds an exisitence for instance attributes via ModuleAnalyzer
before getattr-check.

CHANGES

@@ -27,6 +27,7 @@ Bugs fixed
 ----------
 
 * #7886: autodoc: TypeError is raised on mocking generic-typed classes
+* #904: autodoc: An instance attribute cause a crash of autofunction directive
 * #7839: autosummary: cannot handle umlauts in function names
 * #7865: autosummary: Failed to extract summary line when abbreviations found
 * #7866: autosummary: Failed to extract correct summary line when docstring

sphinx/ext/autodoc/__init__.py

@@ -1869,15 +1869,34 @@ def can_document_member(cls, member: Any, membername: str, isattr: bool, parent:
     def document_members(self, all_members: bool = False) -> None:
         pass
 
+    def isinstanceattribute(self) -> bool:
+        """Check the subject is an instance attribute."""
+        try:
+            analyzer = ModuleAnalyzer.for_module(self.modname)
+            attr_docs = analyzer.find_attr_docs()
+            if self.objpath:
+                key = ('.'.join(self.objpath[:-1]), self.objpath[-1])
+                if key in attr_docs:
+                    return True
+
+            return False
+        except PycodeError:
+            return False
+
     def import_object(self) -> Any:
-        ret = super().import_object()
-        if inspect.isenumattribute(self.object):
-            self.object = self.object.value
-        if inspect.isattributedescriptor(self.object):
-            self._datadescriptor = True
-        else:
-            # if it's not a data descriptor
+        if self.isinstanceattribute():
+            self.object = INSTANCEATTR
             self._datadescriptor = False
+            ret = True
+        else:
+            ret = super().import_object()
+            if inspect.isenumattribute(self.object):
+                self.object = self.object.value
+            if inspect.isattributedescriptor(self.object):
+                self._datadescriptor = True
+            else:
+                # if it's not a data descriptor
+                self._datadescriptor = False
         return ret
 
     def get_real_modname(self) -> str:

tests/test_ext_autodoc.py

@@ -1047,7 +1047,7 @@ def test_class_attributes(app):
 
 
 @pytest.mark.sphinx('html', testroot='ext-autodoc')
-def test_instance_attributes(app):
+def test_autoclass_instance_attributes(app):
     options = {"members": None}
     actual = do_autodoc(app, 'class', 'target.InstAttCls', options)
     assert list(actual) == [
@@ -1120,6 +1120,19 @@ def test_instance_attributes(app):
     ]
 
 
+@pytest.mark.sphinx('html', testroot='ext-autodoc')
+def test_autoattribute_instance_attributes(app):
+    actual = do_autodoc(app, 'attribute', 'target.InstAttCls.ia1')
+    assert list(actual) == [
+        '',
+        '.. py:attribute:: InstAttCls.ia1',
+        '   :module: target',
+        '',
+        '   Doc comment for instance attribute InstAttCls.ia1',
+        ''
+    ]
+
+
 @pytest.mark.sphinx('html', testroot='ext-autodoc')
 def test_slots(app):
     options = {"members": None,