fix: do not treat overridden methods as inherited when mixing a generic base with a plain base

CHANGELOG.md

@@ -4,6 +4,8 @@
 
 ## Unreleased: pdoc next
 
+- Fix overridden methods being shown as inherited when a class mixes a `Generic[...]` base with a plain base class.
+  ([#887](https://github.com/mitmproxy/pdoc/pull/887), @SAY-5)
 - Fix incorrect ordering of `start-after`/`end-before` in RST include directives.
   ([#876](https://github.com/mitmproxy/pdoc/pull/876), @JohanKarlbergg)
 - Support Pydantic [`computed_field`](https://docs.pydantic.dev/2.0/usage/computed_fields/) descriptions ([#855](https://github.com/mitmproxy/pdoc/pull/855), @avhz)

pdoc/doc.py

@@ -683,9 +683,15 @@ def _bases(self) -> tuple[type, ...]:
 
         # __mro__ and __orig_bases__ differ between Python versions and special cases like TypedDict/NamedTuple.
         # This here is a pragmatic approximation of what we want.
+        # Only prepend __orig_bases__ entries absent from __mro__, so a plain base cannot shadow the class itself.
+        mro = self.obj.__mro__
         return (
-            *(base for base in orig_bases if isinstance(base, type)),
-            *self.obj.__mro__,
+            *(
+                base
+                for base in orig_bases
+                if isinstance(base, type) and base not in mro
+            ),
+            *mro,
         )
 
     @cached_property

test/test_doc.py

@@ -186,3 +186,19 @@ def test_source_file_method():
     assert m.members["Foo"].members["a_cached_function"].source_file == (
         here / "testdata" / "demo_long.py"
     )
+
+
+def test_overridden_method_with_generic_base():
+    mod = extract.load_module(
+        extract.parse_spec(here / "testdata" / "generic_mixin.py")
+    )
+
+    m = Module(mod)
+    cls = m.members["Mixed"]
+    assert isinstance(cls, Class)
+
+    for name in ("generic_method", "plain_method"):
+        member = cls.members[name]
+        assert member.taken_from == ("generic_mixin", f"Mixed.{name}")
+        assert member.docstring == f"{name} implementation docstring"
+        assert member in cls.own_members

test/testdata/generic_mixin.py

@@ -0,0 +1,23 @@
+from abc import ABC
+from typing import Generic
+from typing import TypeVar
+
+T = TypeVar("T")
+
+
+class GenericBase(ABC, Generic[T]):
+    def generic_method(self):
+        pass
+
+
+class PlainBase(ABC):
+    def plain_method(self):
+        pass
+
+
+class Mixed(GenericBase[T], PlainBase):
+    def generic_method(self):
+        """generic_method implementation docstring"""
+
+    def plain_method(self):
+        """plain_method implementation docstring"""