b024 no longer treats assigned class vars as abstract (#494)

Author: jakkdl

.github/workflows/ci.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12", "3.13-dev"]
+        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12", "3.13"]
 
         os: [ubuntu-latest]
 

README.rst

@@ -357,6 +357,11 @@ MIT
 Change Log
 ----------
 
+
+FUTURE
+~~~~~~
+* B024: No longer treats assigned class variables as abstract (#471)
+
 24.8.19
 ~~~~~~~
 

bugbear.py

@@ -996,7 +996,7 @@ def is_str_or_ellipsis(node):
         for stmt in node.body:
             # https://github.com/PyCQA/flake8-bugbear/issues/293
             # Ignore abc's that declares a class attribute that must be set
-            if isinstance(stmt, (ast.AnnAssign, ast.Assign)):
+            if isinstance(stmt, ast.AnnAssign) and stmt.value is None:
                 has_abstract_method = True
                 continue
 

tests/b024.py

@@ -10,7 +10,7 @@
 
 """
 Should emit:
-B024 - on lines 17, 34, 52, 58, 69, 74, 84, 89
+B024 - on lines 17, 52, 58, 69, 74, 123, 129
 """
 
 
@@ -31,7 +31,7 @@ def method(self):
         foo()
 
 
-class Base_4(ABC):
+class Base_4(ABC): # safe
     @notabc.abstractmethod
     def method(self):
         foo()
@@ -112,16 +112,24 @@ def method(self):
         foo()
 
 
-class abc_set_class_variable_1(ABC):  # safe
+# safe, see https://github.com/PyCQA/flake8-bugbear/issues/293
+class abc_annasign_empty_class_variable_1(ABC):
     foo: int
+    def method(self):
+        foo()
 
 
-class abc_set_class_variable_2(ABC):  # safe
+# *not* safe, see https://github.com/PyCQA/flake8-bugbear/issues/471
+class abc_assign_class_variable(ABC):
     foo = 2
+    def method(self):
+        foo()
 
 
-class abc_set_class_variable_3(ABC):  # safe
+class abc_annassign_class_variable(ABC):  # *not* safe, see #471
     foo: int = 2
+    def method(self):
+        foo()
 
 
 # this doesn't actually declare a class variable, it's just an expression

tests/test_bugbear.py

@@ -461,6 +461,8 @@ def test_b024(self):
             B024(58, 0, vars=("MetaBase_1",)),
             B024(69, 0, vars=("abc_Base_1",)),
             B024(74, 0, vars=("abc_Base_2",)),
+            B024(123, 0, vars=("abc_assign_class_variable",)),
+            B024(129, 0, vars=("abc_annassign_class_variable",)),
         )
         self.assertEqual(errors, expected)