fix: Fix extensions loader

src/griffe/agents/extensions/base.py

@@ -2,13 +2,14 @@
 
 from __future__ import annotations
 
+import ast
 import enum
 from collections import defaultdict
 from inspect import isclass
-from types import ModuleType
 from typing import TYPE_CHECKING, Any, Sequence, Type, Union
 
 from griffe.agents.base import BaseInspector, BaseVisitor
+from griffe.agents.nodes import ObjectNode
 
 if TYPE_CHECKING:
     from griffe.agents.inspector import Inspector
@@ -214,7 +215,44 @@ def after_inspection(self) -> list[InspectorExtension]:
         return self._inspectors[When.after_all]
 
 
-builtin_extensions: dict[str, ModuleType] = {}
+builtin_extensions: set[str] = {
+    "hybrid",
+}
+
+
+def load_extension(extension: str | dict[str, Any] | Extension | Type[Extension]) -> Extension:
+    """Load a configured extension.
+
+    Parameters:
+        extension: An extension, with potential configuration options.
+
+    Returns:
+        An extension instance.
+    """
+    if isinstance(extension, (VisitorExtension, InspectorExtension)):
+        return extension
+
+    if isclass(extension) and issubclass(extension, (VisitorExtension, InspectorExtension)):  # type: ignore[arg-type]
+        return extension()  # type: ignore[operator]
+
+    if isinstance(extension, dict):
+        import_path, options = next(iter(extension.items()))
+
+    else:  # we consider it's a string
+        import_path = str(extension)
+        options = {}
+
+    if import_path in builtin_extensions:
+        import_path = f"griffe.agents.extensions.{import_path}"
+
+    module = __import__(import_path, level=0)
+    ext_path = import_path.split(".")[1:]
+    ext_module = module
+    for part in ext_path:
+        ext_module = getattr(ext_module, part)
+
+    # TODO: handle AttributeError
+    return ext_module.Extension(**options)
 
 
 def load_extensions(exts: Sequence[str | dict[str, Any] | Extension | Type[Extension]]) -> Extensions:  # noqa: WPS231
@@ -227,30 +265,6 @@ def load_extensions(exts: Sequence[str | dict[str, Any] | Extension | Type[Exten
         An extensions container.
     """
     extensions = Extensions()
-
     for extension in exts:
-        if isinstance(extension, (str, dict)):
-            if isinstance(extension, str):
-                if extension in builtin_extensions:
-                    ext_module = builtin_extensions[extension]
-                else:
-                    ext_module = __import__(extension)
-                options = {}
-            elif isinstance(extension, dict):
-                import_path = next(extension.keys())  # type: ignore[arg-type,call-overload]
-                if import_path in builtin_extensions:
-                    ext_module = builtin_extensions[import_path]
-                else:
-                    ext_module = __import__(import_path)
-                options = next(extension.values())  # type: ignore[arg-type,call-overload]
-
-            # TODO: handle AttributeError
-            extensions.add(ext_module.Extension(**options))  # type: ignore[attr-defined]
-
-        elif isinstance(extension, (VisitorExtension, InspectorExtension)):
-            extensions.add(extension)
-
-        elif isclass(extension) and issubclass(extension, (VisitorExtension, InspectorExtension)):
-            extensions.add(extension())
-
+        extensions.add(load_extension(extension))
     return extensions