fix: Prevent cyclic aliases by not overwriting a module member with a…

…n indirect alias to itself

Issue #122: #122

src/griffe/dataclasses.py

@@ -1111,6 +1111,20 @@ def target(self, value: Object | Alias) -> None:
         if self.parent is not None:
             self._target.aliases[self.path] = self
 
+    @property
+    def final_target(self) -> Object:
+        """Resolve and return the final target, if possible.
+
+        This will iterate through the targets until a non-alias object is found.
+
+        Returns:
+            The final target.
+        """
+        target = self.target
+        while target.is_alias:
+            target = target.target  # type: ignore[union-attr]
+        return target  # type: ignore[return-value]
+
     def resolve_target(self) -> None:
         """Resolve the target.
 

src/griffe/loader.py

@@ -13,6 +13,7 @@
 from __future__ import annotations
 
 import sys
+from contextlib import suppress
 from datetime import datetime, timezone
 from typing import TYPE_CHECKING, Any, Sequence, cast
 from warnings import warn
@@ -296,13 +297,24 @@ def expand_wildcards(
                 old_lineno = getattr(old_member, "alias_lineno", old_member.lineno or 0)
                 overwrite = alias_lineno > old_lineno  # type: ignore[operator]
             if not self_alias and (not already_present or overwrite):
-                obj[new_member.name] = Alias(
+                alias = Alias(
                     new_member.name,
                     new_member,
                     lineno=alias_lineno,
                     endlineno=alias_endlineno,
                     parent=obj,  # type: ignore[arg-type]
                 )
+                if already_present:
+                    prev_member = obj[new_member.name]
+                    with suppress(AliasResolutionError):
+                        if prev_member.is_module:
+                            if prev_member.is_alias:
+                                prev_member = prev_member.final_target
+                            if alias.final_target is prev_member:
+                                # alias named after the module it targets:
+                                # skip to avoid cyclic aliases
+                                continue
+                obj[new_member.name] = alias
 
     def resolve_module_aliases(
         self,