Become compatible with flake8 5.0.0

.flake8

@@ -21,5 +21,6 @@ max-line-length = 80
 max-complexity = 12
 select = B,C,E,F,W,Y,B9
 per-file-ignores =
-  *.py: E203, E501, W503, W291, W293
-  *.pyi: E301, E302, E305, E501, E701, E704, W503
+  # TODO: reenable some of the bugbear checks
+  *.py: B950, E203, E501, W503, W291, W293
+  *.pyi: B902, B903, B950, E301, E302, E305, E501, E701, E704, W503

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Change Log
 
+## Unreleased
+
+* Add support for flake8 5.0.0.
+
 ## 22.8.0
 
 New error codes:

pyi.py

@@ -18,17 +18,11 @@
 from pathlib import Path
 from typing import TYPE_CHECKING, Any, ClassVar, NamedTuple
 
-from flake8 import checker  # type: ignore[import]
+import flake8  # type: ignore[import]
+from flake8 import checker
 from flake8.options.manager import OptionManager  # type: ignore[import]
-from flake8.plugins.manager import Plugin  # type: ignore[import]
 from flake8.plugins.pyflakes import FlakesChecker  # type: ignore[import]
-from pyflakes.checker import (
-    PY2,
-    ClassDefinition,
-    ClassScope,
-    FunctionScope,
-    ModuleScope,
-)
+from pyflakes.checker import ClassDefinition, ClassScope, FunctionScope, ModuleScope
 
 if sys.version_info >= (3, 9):
     from ast import unparse
@@ -48,6 +42,19 @@ def unparse(node: ast.AST) -> str:
 __version__ = "22.8.0"
 
 LOG = logging.getLogger("flake8.pyi")
+FLAKE8_MAJOR_VERSION = flake8.__version_info__[0]
+
+if FLAKE8_MAJOR_VERSION < 5:
+    import warnings
+
+    warnings.warn(
+        (
+            "flake8-pyi will drop support for running with flake8 < 5.0.0 "
+            "in a future version. This will not happen until November 2022 "
+            "at the earliest."
+        ),
+        category=FutureWarning,
+    )
 
 
 class Error(NamedTuple):
@@ -223,9 +230,8 @@ def CLASSDEF(self, node: ast.ClassDef) -> None:
             self.handleNode(decorator, node)
         for baseNode in node.bases:
             self.deferHandleNode(baseNode, node)
-        if not PY2:
-            for keywordNode in node.keywords:
-                self.deferHandleNode(keywordNode, node)
+        for keywordNode in node.keywords:
+            self.deferHandleNode(keywordNode, node)
         self.pushScope(ClassScope)
         # doctest does not process doctest within a doctest
         # classes within classes are processed.
@@ -249,20 +255,26 @@ def handleNodeDelete(self, node: ast.AST) -> None:
 
 
 class PyiAwareFileChecker(checker.FileChecker):
-    def run_check(self, plugin: Plugin, **kwargs: Any) -> Any:
+    def run_check(self, plugin, **kwargs: Any) -> Any:
         if self.filename == "-":
             filename = self.options.stdin_display_name
         else:
             filename = self.filename
 
-        if filename.endswith(".pyi") and plugin["plugin"] == FlakesChecker:
-            LOG.info(
-                "Replacing FlakesChecker with PyiAwareFlakesChecker while "
-                "checking %r",
-                filename,
+        if filename.endswith(".pyi"):
+            log_msg = (
+                f"Replacing FlakesChecker with PyiAwareFlakesChecker while "
+                f"checking {filename!r}"
             )
-            plugin = dict(plugin)
-            plugin["plugin"] = PyiAwareFlakesChecker
+            if FLAKE8_MAJOR_VERSION < 5:
+                if plugin["plugin"] is FlakesChecker:
+                    LOG.info(log_msg)
+                    plugin = dict(plugin)
+                    plugin["plugin"] = PyiAwareFlakesChecker
+            else:
+                if plugin.obj is FlakesChecker:
+                    LOG.info(log_msg)
+                    plugin = plugin._replace(obj=PyiAwareFlakesChecker)
         return super().run_check(plugin, **kwargs)
 
 

setup.py

@@ -38,7 +38,7 @@
     zip_safe=False,
     python_requires=">=3.7",
     install_requires=[
-        "flake8 >= 3.2.1, < 5.0.0",
+        "flake8 >= 3.2.1, < 6.0.0",
         "pyflakes >= 2.1.1",
         'ast-decompiler <1.0; python_version < "3.9"',
     ],

tests/typevar.pyi

@@ -37,7 +37,7 @@ class BadClass:
     def bad_class_method(cls: type[_S], arg: int) -> _S: ...  # Y019 Use "_typeshed.Self" instead of "_S", e.g. "def bad_class_method(cls: type[Self], arg: int) -> Self: ..."
 
 class GoodClass:
-    def __new__(cls: type[Self], *args: list[int], **kwargs: set[str]) -> Self:  ...
+    def __new__(cls: type[Self], *args: list[int], **kwargs: set[str]) -> Self: ...
     def good_instance_method_1(self: Self, arg: bytes) -> Self: ...
     def good_instance_method_2(self, arg1: _S, arg2: _S) -> _S: ...
     @classmethod