EHN: also raise B006 for list/dict/set comprehensions (#186)

* EHN: also raise B006 for list/dict comprehensions

* Oh AST inconsistency ... you're not a friend

* I forgot about set comprehensions

* sigh, hi black

Author: ichard26

README.rst

@@ -222,6 +222,11 @@ MIT
 Change Log
 ----------
 
+Unreleased
+~~~~~~~~~~
+
+* Update B006: list, dictionary, and set comprehensions are now also disallowed (#186)
+
 21.9.1
 ~~~~~~
 

bugbear.py

@@ -328,7 +328,9 @@ def check_for_b005(self, node):
 
     def check_for_b006(self, node):
         for default in node.args.defaults + node.args.kw_defaults:
-            if isinstance(default, B006.mutable_literals):
+            if isinstance(
+                default, (*B006.mutable_literals, *B006.mutable_comprehensions)
+            ):
                 self.errors.append(B006(default.lineno, default.col_offset))
             elif isinstance(default, ast.Call):
                 call_path = ".".join(self.compose_call_path(default.func))
@@ -653,6 +655,7 @@ def visit(self, node):
     )
 )
 B006.mutable_literals = (ast.Dict, ast.List, ast.Set)
+B006.mutable_comprehensions = (ast.ListComp, ast.DictComp, ast.SetComp)
 B006.mutable_calls = {
     "Counter",
     "OrderedDict",

tests/b006_b008.py

@@ -119,3 +119,15 @@ def operators_ok_unqualified(
     v=attrgetter("foo"), v2=itemgetter("foo"), v3=methodcaller("foo")
 ):
     pass
+
+
+def list_comprehension_also_not_okay(default=[i ** 2 for i in range(3)]):
+    pass
+
+
+def dict_comprehension_also_not_okay(default={i: i ** 2 for i in range(3)}):
+    pass
+
+
+def set_comprehension_also_not_okay(default={i ** 2 for i in range(3)}):
+    pass

tests/test_bugbear.py

@@ -103,6 +103,9 @@ def test_b006_b008(self):
                 B006(70, 32),
                 B008(98, 29),
                 B008(102, 44),
+                B006(124, 45 if sys.version_info >= (3, 8) else 46),
+                B006(128, 45),
+                B006(132, 44),
             ),
         )