Fix: Ensure extendable instance is instance of its own class

.github/workflows/ci.yml

@@ -12,15 +12,19 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v2
-      - uses: pre-commit/action@v2.0.2
+        with:
+          python-version: "3.10" # Specify the desired Python version
+      - uses: pre-commit/action@v3.0.1
+        with:
+          extra_args: --all-files
 
   tests:
     name: "Python ${{ matrix.python-version }}"
     runs-on: "ubuntu-latest"
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.7", "3.8", "3.9", "3.10", "pypy-3.7", "3.11", "3.12"]
+        python-version: ["3.8", "3.9", "3.10", "pypy-3.7", "3.11", "3.12", "3.13"]
     steps:
       - uses: "actions/checkout@v2"
       - uses: "actions/setup-python@v2"

.pre-commit-config.yaml

@@ -2,11 +2,11 @@ default_language_version:
   python: python3
 repos:
   - repo: https://github.com/psf/black
-    rev: 22.3.0
+    rev: 25.1.0
     hooks:
       - id: black
   - repo: https://github.com/myint/autoflake
-    rev: v1.4
+    rev: v2.3.1
     hooks:
       - id: autoflake
         args:
@@ -15,7 +15,7 @@ repos:
           - --remove-all-unused-imports
           - --remove-duplicate-keys
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v4.0.1
+    rev: v5.0.0
     hooks:
       - id: check-toml
       - id: check-yaml
@@ -25,18 +25,19 @@ repos:
     rev: "3.9.2"
     hooks:
       - id: flake8
-        additional_dependencies: ["flake8-bugbear==21.4.3"]
+        name: flake8
+        additional_dependencies: ["flake8-bugbear==21.9.2"]
   - repo: https://github.com/pre-commit/mirrors-isort
-    rev: v5.8.0
+    rev: v5.10.1
     hooks:
       - id: isort
-  - repo: https://github.com/myint/docformatter
-    rev: v1.4
+  - repo: https://github.com/PyCQA/docformatter
+    rev: eb1df347edd128b30cd3368dddc3aa65edcfac38
     hooks:
       - id: docformatter
         args: ["--in-place", "--wrap-summaries=88"]
   - repo: https://github.com/asottile/pyupgrade
-    rev: v2.29.1
+    rev: v3.19.1
     hooks:
       - id: pyupgrade
         args: ["--py3-plus", "--py36-plus"]

news/18.bugfix.rst

@@ -0,0 +1 @@
+When checking if an instance of extendable class is a type of itself, first check if both classes have the same __xreg_name__ attribute.

src/extendable/main.py

@@ -87,9 +87,9 @@
         return clone
 
 
-_extendable_class_defs_by_module: OrderedDict[
-    str, List[ExtendableClassDef]
-] = collections.OrderedDict()
+_extendable_class_defs_by_module: OrderedDict[str, List[ExtendableClassDef]] = (
+    collections.OrderedDict()
+)
 
 
 def __register_class_def__(module: str, cls_def: ExtendableClassDef) -> None:
@@ -108,7 +108,7 @@
 
     @no_type_check
     def __new__(metacls, name, bases, namespace, extends=None, **kwargs):
-        """create the expected class and collect the class definition that will be used
+        """Create the expected class and collect the class definition that will be used
         at the end of registry load process to build the final class."""
         class_def = None
         if isinstance(extends, bool) and extends:
@@ -251,6 +251,18 @@
     ###############################################################
     # concrete methods provided to the final class by the metaclass
     ###############################################################
+    def __instancecheck__(self, instance: Any) -> bool:  # noqa: B902
+        """Implement issubclass(sub, cls)."""
+        if not hasattr(instance, "__xreg_name__"):
+            return False
+
+        if instance.__xreg_name__ == self.__xreg_name__:
+            # this is the same class
+            return True
+        # self is a class and instance is an instance of a class
+        if self.__xreg_name__ in instance.__xreg_all_base_names__:
+            return True
+        return super().__instancecheck__(instance)
 
     def __subclasscheck__(cls, subclass: Any) -> bool:  # noqa: B902
         """Implement issubclass(sub, cls)."""

src/extendable/registry.py

@@ -8,8 +8,9 @@
 
 
 class ExtendableRegistryListener:
-    def on_registry_initialized(self, registry: "ExtendableClassesRegistry") -> None:
-        ...
+    def on_registry_initialized(
+        self, registry: "ExtendableClassesRegistry"
+    ) -> None: ...
 
     def before_init_registry(
         self,

tests/test_registry_init.py

@@ -1,4 +1,5 @@
 """Test registry loading."""
+
 from extendable.registry import ExtendableClassesRegistry, ExtendableRegistryListener
 
 

tests/test_simple.py

@@ -331,3 +331,23 @@ class C(B):
     assert isinstance(C(), A().__class__)
     assert isinstance(B(), A)
     assert isinstance(B(), A().__class__)
+
+
+def test_isinstance_no_extend(test_registry):
+    # in this test our class are not extended
+    # we chech that the isinstance works as expected
+    # when we have no extends by the classes
+    # are extendable by default
+    class A(metaclass=ExtendableMeta):
+        pass
+
+    class B(A):
+        pass
+
+    test_registry.init_registry()
+
+    assert isinstance(A(), A)
+    assert isinstance(B(), A)
+    assert isinstance(B(), B)
+    assert isinstance(B(), A().__class__)
+    assert isinstance(B(), B().__class__)

tox.ini

@@ -1,11 +1,11 @@
 [gh-actions]
 python =
-    3.7: py37, typing
     3.8: py38, typing
     3.9: py39, typing, pypi-description
     3.10: py310, typing
     3.11: py311, typing
     3.12: py312, typing
+    3.13: py313, typing
     pypy-3.7: pypy37
 
 [tox]
@@ -17,6 +17,7 @@ envlist =
     py310
     py311
     py312
+    py313
     pypy37
     lint
     typing