Implement B024 and B027 (#738)

resources/test/fixtures/B024.py

@@ -0,0 +1,129 @@
+"""
+Should emit:
+B024 - on lines 17, 34, 52, 58, 69, 74, 84, 89
+"""
+
+import abc
+import abc as notabc
+from abc import ABC, ABCMeta
+from abc import abstractmethod
+from abc import abstractmethod as abstract
+from abc import abstractmethod as abstractaoeuaoeuaoeu
+from abc import abstractmethod as notabstract
+
+import foo
+
+
+class Base_1(ABC):  # error
+    def method(self):
+        foo()
+
+
+class Base_2(ABC):
+    @abstractmethod
+    def method(self):
+        foo()
+
+
+class Base_3(ABC):
+    @abc.abstractmethod
+    def method(self):
+        foo()
+
+
+class Base_4(ABC):
+    @notabc.abstractmethod
+    def method(self):
+        foo()
+
+
+class Base_5(ABC):
+    @abstract
+    def method(self):
+        foo()
+
+
+class Base_6(ABC):
+    @abstractaoeuaoeuaoeu
+    def method(self):
+        foo()
+
+
+class Base_7(ABC):  # error
+    @notabstract
+    def method(self):
+        foo()
+
+
+class MetaBase_1(metaclass=ABCMeta):  # error
+    def method(self):
+        foo()
+
+
+class MetaBase_2(metaclass=ABCMeta):
+    @abstractmethod
+    def method(self):
+        foo()
+
+
+class abc_Base_1(abc.ABC):  # error
+    def method(self):
+        foo()
+
+
+class abc_Base_2(metaclass=abc.ABCMeta):  # error
+    def method(self):
+        foo()
+
+
+class notabc_Base_1(notabc.ABC):  # safe
+    def method(self):
+        foo()
+
+
+class multi_super_1(notabc.ABC, abc.ABCMeta):  # safe
+    def method(self):
+        foo()
+
+
+class multi_super_2(notabc.ABC, metaclass=abc.ABCMeta):  # safe
+    def method(self):
+        foo()
+
+
+class non_keyword_abcmeta_1(ABCMeta):  # safe
+    def method(self):
+        foo()
+
+
+class non_keyword_abcmeta_2(abc.ABCMeta):  # safe
+    def method(self):
+        foo()
+
+
+# very invalid code, but that's up to mypy et al to check
+class keyword_abc_1(metaclass=ABC):  # safe
+    def method(self):
+        foo()
+
+
+class keyword_abc_2(metaclass=abc.ABC):  # safe
+    def method(self):
+        foo()
+
+
+class abc_set_class_variable_1(ABC):  # safe
+    foo: int
+
+
+class abc_set_class_variable_2(ABC):  # safe
+    foo = 2
+
+
+class abc_set_class_variable_3(ABC):  # safe
+    foo: int = 2
+
+
+# this doesn't actually declare a class variable, it's just an expression
+class abc_set_class_variable_4(ABC):  # error
+    foo

resources/test/fixtures/B027.py

@@ -0,0 +1,89 @@
+"""
+Should emit:
+B027 - on lines 12, 15, 18, 22, 30
+"""
+
+import abc
+from abc import ABC
+from abc import abstractmethod
+from abc import abstractmethod as notabstract
+
+
+class AbstractClass(ABC):
+    def empty_1(self):  # error
+        ...
+
+    def empty_2(self):  # error
+        pass
+
+    def empty_3(self):  # error
+        """docstring"""
+        ...
+
+    def empty_4(self):  # error
+        """multiple ellipsis/pass"""
+        ...
+        pass
+        ...
+        pass
+
+    @notabstract
+    def empty_5(self):  # error
+        ...
+
+    @abstractmethod
+    def abstract_1(self):
+        ...
+
+    @abstractmethod
+    def abstract_2(self):
+        pass
+
+    @abc.abstractmethod
+    def abstract_3(self):
+        ...
+
+    def body_1(self):
+        print("foo")
+        ...
+
+    def body_2(self):
+        self.body_1()
+
+
+class NonAbstractClass:
+    def empty_1(self):  # safe
+        ...
+
+    def empty_2(self):  # safe
+        pass
+
+
+# ignore @overload, fixes issue #304
+# ignore overload with other imports, fixes #308
+import typing
+import typing as t
+import typing as anything
+from typing import Union, overload
+
+
+class AbstractClass(ABC):
+    @overload
+    def empty_1(self, foo: str):
+        ...
+
+    @typing.overload
+    def empty_1(self, foo: int):
+        ...
+
+    @t.overload
+    def empty_1(self, foo: list):
+        ...
+
+    @anything.overload
+    def empty_1(self, foo: float):
+        ...
+
+    @abstractmethod
+    def empty_1(self, foo: Union[str, int, list, float]):
+        ...