doc(B024): astral-sh#14455 add annotated but unassgined class variables

https://github.com/cmp0xff/astral-sh-docs/commit/2dc8f3baa78c7a57b5650f2347f6c1cf2a27255b astral-sh/docs#106 (comment) astral-sh#14455 (comment)

crates/ruff_linter/src/rules/flake8_bugbear/rules/abstract_base_class.rs

@@ -11,39 +11,47 @@ use crate::checkers::ast::Checker;
 use crate::registry::Rule;
 
 /// ## What it does
-/// Checks for abstract classes without abstract methods.
+/// Checks for abstract classes without abstract methods or abstract class variables.
+/// Annotated but unassigned class variables are regarded as abstract.
 ///
 /// ## Why is this bad?
 /// Abstract base classes are used to define interfaces. If an abstract base
-/// class has no abstract methods, you may have forgotten to add an abstract
-/// method to the class or omitted an `@abstractmethod` decorator.
+/// class has no abstract methods or abstract class variables, you may have forgotten
+/// to add an abstract method to the class or omitted an `@abstractmethod` decorator.
 ///
 /// If the class is _not_ meant to be used as an interface, consider removing
 /// the `ABC` base class from the class definition.
 ///
 /// ## Example
 /// ```python
 /// from abc import ABC
+/// from typing import ClassVar
 ///
 ///
 /// class Foo(ABC):
+///     class_var: ClassVar[str] = "assigned"
+///
 ///     def method(self):
 ///         bar()
 /// ```
 ///
 /// Use instead:
 /// ```python
 /// from abc import ABC, abstractmethod
+/// from typing import ClassVar
 ///
 ///
 /// class Foo(ABC):
+///     class_var: ClassVar[str]  # unassigned
+///
 ///     @abstractmethod
 ///     def method(self):
 ///         bar()
 /// ```
 ///
 /// ## References
 /// - [Python documentation: `abc`](https://docs.python.org/3/library/abc.html)
+/// - [Python documentation: `typing.ClassVar`](https://docs.python.org/3/library/typing.html#typing.ClassVar)
 #[violation]
 pub struct AbstractBaseClassWithoutAbstractMethod {
     name: String,
@@ -53,7 +61,7 @@ impl Violation for AbstractBaseClassWithoutAbstractMethod {
     #[derive_message_formats]
     fn message(&self) -> String {
         let AbstractBaseClassWithoutAbstractMethod { name } = self;
-        format!("`{name}` is an abstract base class, but it has no abstract methods")
+        format!("`{name}` is an abstract base class, but it has neither abstract methods nor abstract class variables")
     }
 }
 

scripts/generate_mkdocs.py

@@ -110,7 +110,8 @@ def generate_rule_metadata(rule_doc: Path) -> None:
     For example:
     ```yaml
     ---
-    description: Checks for abstract classes without abstract methods.
+    description: Checks for abstract classes without abstract methods or abstract class
+    variables.
     tags:
     - B024
     ---