LTS v21.12 Deprecations (#2306)

Co-authored-by: Néstor Pérez <25409753+prryplatypus@users.noreply.github.com>

sanic/base/meta.py

@@ -0,0 +1,6 @@
+class SanicMeta(type):
+    @classmethod
+    def __prepare__(metaclass, name, bases, **kwds):
+        cls = super().__prepare__(metaclass, name, bases, **kwds)
+        cls["__slots__"] = ()
+        return cls

sanic/base/root.py

@@ -0,0 +1,63 @@
+import re
+
+from typing import Any
+
+from sanic.base.meta import SanicMeta
+from sanic.exceptions import SanicException
+from sanic.mixins.exceptions import ExceptionMixin
+from sanic.mixins.listeners import ListenerMixin
+from sanic.mixins.middleware import MiddlewareMixin
+from sanic.mixins.routes import RouteMixin
+from sanic.mixins.signals import SignalMixin
+
+
+VALID_NAME = re.compile(r"^[a-zA-Z_][a-zA-Z0-9_\-]*$")
+
+
+class BaseSanic(
+    RouteMixin,
+    MiddlewareMixin,
+    ListenerMixin,
+    ExceptionMixin,
+    SignalMixin,
+    metaclass=SanicMeta,
+):
+    __slots__ = ("name",)
+
+    def __init__(self, name: str = None, *args: Any, **kwargs: Any) -> None:
+        class_name = self.__class__.__name__
+
+        if name is None:
+            raise SanicException(
+                f"{class_name} instance cannot be unnamed. "
+                "Please use Sanic(name='your_application_name') instead.",
+            )
+
+        if not VALID_NAME.match(name):
+            raise SanicException(
+                f"{class_name} instance named '{name}' uses an invalid "
+                "format. Names must begin with a character and may only "
+                "contain alphanumeric characters, _, or -."
+            )
+
+        self.name = name
+
+        for base in BaseSanic.__bases__:
+            base.__init__(self, *args, **kwargs)  # type: ignore
+
+    def __str__(self) -> str:
+        return f"<{self.__class__.__name__} {self.name}>"
+
+    def __repr__(self) -> str:
+        return f'{self.__class__.__name__}(name="{self.name}")'
+
+    def __setattr__(self, name: str, value: Any) -> None:
+        try:
+            super().__setattr__(name, value)
+        except AttributeError as e:
+            raise AttributeError(
+                f"Setting variables on {self.__class__.__name__} instances is "
+                "not allowed. You should change your "
+                f"{self.__class__.__name__} instance to use "
+                f"instance.ctx.{name} instead.",
+            ) from e