gh-130992: Add Interface Enforcement to abc Module

Lib/abc.py

@@ -3,6 +3,7 @@
 
 """Abstract Base Classes (ABCs) according to PEP 3119."""
 
+import inspect
 
 def abstractmethod(funcobj):
     """A decorator indicating abstract methods.
@@ -186,3 +187,35 @@ class ABC(metaclass=ABCMeta):
     inheritance.
     """
     __slots__ = ()
+
+
+class InterfaceMeta(ABCMeta):
+    """Metaclass to force implementation of methods in derived classes with the same signature."""
+
+    def __new__(mcs, name, bases, namespace):
+        # If it is not a base class (Interface), check implementation
+        if bases:
+            for base in bases:
+                if isinstance(base, InterfaceMeta):
+                    for attr_name, attr_value in base.__dict__.items():
+                        # Checks if the base attribute is a method and not a variable
+                        if callable(attr_value) and not attr_name.startswith('__'):
+                            if attr_name not in namespace:
+                                raise TypeError(f"Class '{name}' must implement method '{attr_name}' of interface '{base.__name__}'")
+
+                            # Compare method signatures
+                            base_signature = inspect.signature(attr_value)
+                            derived_signature = inspect.signature(namespace[attr_name])
+
+                            if base_signature != derived_signature:
+                                raise TypeError(
+                                    f"Method '{attr_name}' in class '{name}' does not match the interface signature.\n"
+                                    f"Expected: {base_signature}\n"
+                                    f"Got: {derived_signature}"
+                                )
+        return super().__new__(mcs, name, bases, namespace)
+
+
+class Interface(metaclass=InterfaceMeta):
+    """Base for all interfaces."""
+    pass