Issue 3265: Add WPS476 SneakyTypeVarWithDefaultViolation

CHANGELOG.md

@@ -19,9 +19,10 @@ Semantic versioning in our case means:
 
 ## 1.1.0 WIP
 
-### Features
+### Rules
 
 - Forbids to use `await` in `for` loop, #1600
+- Adds `WPS477`: do not allow `TypeVarTuple` after a `TypeVar` with a default #3265
 
 ### Command line utility
 

pyproject.toml

@@ -232,6 +232,7 @@ addopts = [
 omit = [
   # All version specific tests:
   "tests/**/*312.py",
+  "tests/**/*313.py"
 ]
 
 # Here we specify plugins for coverage to be used:

tests/fixtures/noqa/noqa313.py

@@ -0,0 +1,11 @@
+"""
+This file contains all possible violations for python 3.13+.
+
+It is used for e2e tests.
+"""
+
+class NewStyleGenerics[
+    TypeVarDefault=int,
+    *FollowingTuple=*tuple[int, ...]  # noqa: WPS477
+]:
+    """TypeVarTuple follows a defaulted TypeVar."""

tests/test_checker/test_noqa.py

@@ -16,9 +16,12 @@
 import subprocess
 import types
 from collections import Counter
+from typing import Final
 
 import pytest
 
+from wemake_python_styleguide.compat.constants import PY313
+
 #: Used to find violations' codes in output.
 ERROR_PATTERN = re.compile(r'(WPS\d{3})')
 
@@ -33,6 +36,9 @@
     'WPS402',  # we obviously use a lot of `noqa` comments
 )
 
+#: List of ignored violations on python 3.13+.
+IGNORED_VIOLATIONS3_13 = ()
+
 #: Number and count of violations that would be raised.
 SHOULD_BE_RAISED = types.MappingProxyType(
     {
@@ -235,6 +241,7 @@
         'WPS474': 1,
         'WPS475': 1,
         'WPS476': 1,
+        'WPS477': 0,  # enabled only in python 3.13+
         'WPS500': 1,
         'WPS501': 1,
         'WPS502': 0,  # disabled since 1.0.0
@@ -293,19 +300,25 @@
     },
 )
 
+#: Number and count of violations that would be raised.
+SHOULD_BE_RAISED3_13 = types.MappingProxyType({'WPS477': 1})
+
 
 def _assert_errors_count_in_output(
     output,
     errors,
     all_violations,
+    *,
+    total: bool = True,
 ):
     found_errors = Counter(
         (match.group(0) for match in ERROR_PATTERN.finditer(output)),
     )
 
-    for violation in all_violations:
-        key = f'WPS{str(violation.code).zfill(3)}'  # noqa: WPS237
-        assert key in errors, 'Unlisted #noqa violation'
+    if total:  # pragma: no cover
+        for violation in all_violations:
+            key = f'WPS{str(violation.code).zfill(3)}'  # noqa: WPS237
+            assert key in errors, 'Unlisted #noqa violation'
 
     for found_error, found_count in found_errors.items():
         assert found_error in errors, 'Violation without a #noqa count'
@@ -321,19 +334,22 @@ def test_codes(all_violations):
     assert len(SHOULD_BE_RAISED) == len(all_violations)
 
 
+ALWAYS: Final = True  # just for beautiful condition def
+
+
 @pytest.mark.parametrize(
-    ('filename', 'violations'),
+    ('filename', 'violations', 'run_condition'),
     [
-        ('noqa.py', SHOULD_BE_RAISED),
+        ('noqa.py', SHOULD_BE_RAISED, ALWAYS),
+        ('noqa313.py', SHOULD_BE_RAISED3_13, PY313),
     ],
 )
 def test_noqa_fixture_disabled(
-    absolute_path,
-    all_violations,
-    filename,
-    violations,
+    absolute_path, all_violations, filename, violations, run_condition
 ):
     """End-to-End test to check that all violations are present."""
+    if not run_condition:  # pragma: no cover
+        return
     process = subprocess.Popen(
         [
             'flake8',
@@ -355,14 +371,21 @@ def test_noqa_fixture_disabled(
     assert stdout
     assert not stderr.count('WPS')
     _assert_errors_count_in_output(
-        stdout,
-        violations,
-        all_violations,
+        stdout, violations, all_violations, total=filename == 'noqa.py'
     )
 
 
-def test_noqa_fixture(absolute_path):
+@pytest.mark.parametrize(
+    ('filename', 'run_condition'),
+    [
+        ('noqa.py', ALWAYS),
+        ('noqa313.py', PY313),
+    ],
+)
+def test_noqa_fixture(absolute_path, filename, run_condition):
     """End-to-End test to check that `noqa` works."""
+    if not run_condition:  # pragma: no cover
+        return
     process = subprocess.Popen(
         [
             'flake8',
@@ -371,7 +394,7 @@ def test_noqa_fixture(absolute_path):
             '--isolated',
             '--select',
             'WPS, E999',
-            absolute_path('fixtures', 'noqa', 'noqa.py'),
+            absolute_path('fixtures', 'noqa', filename),
         ],
         stdout=subprocess.PIPE,
         stderr=subprocess.PIPE,
@@ -384,15 +407,26 @@ def test_noqa_fixture(absolute_path):
     assert not stderr.count('WPS')
 
 
-def test_noqa_fixture_without_ignore(absolute_path):
+@pytest.mark.parametrize(
+    ('filename', 'ignored_violations', 'run_condition'),
+    [
+        ('noqa.py', IGNORED_VIOLATIONS, ALWAYS),
+        ('noqa313.py', IGNORED_VIOLATIONS3_13, PY313),
+    ],
+)
+def test_noqa_fixture_without_ignore(
+    absolute_path, filename, ignored_violations, run_condition
+):
     """End-to-End test to check that `noqa` works without ignores."""
+    if not run_condition:  # pragma: no cover
+        return
     process = subprocess.Popen(
         [
             'flake8',
             '--isolated',
             '--select',
             'WPS, E999',
-            absolute_path('fixtures', 'noqa', 'noqa.py'),
+            absolute_path('fixtures', 'noqa', filename),
         ],
         stdout=subprocess.PIPE,
         stderr=subprocess.PIPE,
@@ -401,5 +435,5 @@ def test_noqa_fixture_without_ignore(absolute_path):
     )
     stdout, _ = process.communicate()
 
-    for violation in IGNORED_VIOLATIONS:
+    for violation in ignored_violations:
         assert stdout.count(violation) > 0

tests/test_visitors/test_ast/test_classes/test_base_classes/test_base_builtin_classes.py

@@ -1,7 +1,9 @@
 import pytest
 
 from wemake_python_styleguide.violations.oop import BuiltinSubclassViolation
-from wemake_python_styleguide.visitors.ast.classes import WrongClassDefVisitor
+from wemake_python_styleguide.visitors.ast.classes.classdef import (
+    WrongClassDefVisitor,
+)
 
 class_with_base = 'class TestClass({0}): ...'
 

tests/test_visitors/test_ast/test_classes/test_base_classes/test_base_exception_base_class.py

@@ -1,7 +1,9 @@
 from wemake_python_styleguide.violations.best_practices import (
     BaseExceptionSubclassViolation,
 )
-from wemake_python_styleguide.visitors.ast.classes import WrongClassDefVisitor
+from wemake_python_styleguide.visitors.ast.classes.classdef import (
+    WrongClassDefVisitor,
+)
 
 class_with_base = """
 class Meta({0}):

tests/test_visitors/test_ast/test_classes/test_base_classes/test_class_definition_arguments.py

@@ -3,7 +3,9 @@
 from wemake_python_styleguide.violations.best_practices import (
     KwargsUnpackingInClassDefinitionViolation,
 )
-from wemake_python_styleguide.visitors.ast.classes import WrongClassDefVisitor
+from wemake_python_styleguide.visitors.ast.classes.classdef import (
+    WrongClassDefVisitor,
+)
 
 # Wrong:
 

tests/test_visitors/test_ast/test_classes/test_base_classes/test_expression_base_class.py

@@ -1,7 +1,9 @@
 import pytest
 
 from wemake_python_styleguide.violations.oop import WrongBaseClassViolation
-from wemake_python_styleguide.visitors.ast.classes import WrongClassDefVisitor
+from wemake_python_styleguide.visitors.ast.classes.classdef import (
+    WrongClassDefVisitor,
+)
 
 class_with_base = """
 class Meta({0}):

tests/test_visitors/test_ast/test_classes/test_buggy_super.py

@@ -1,7 +1,9 @@
 import pytest
 
 from wemake_python_styleguide.violations.oop import BuggySuperContextViolation
-from wemake_python_styleguide.visitors.ast.classes import BuggySuperCallVisitor
+from wemake_python_styleguide.visitors.ast.classes.methods import (
+    BuggySuperCallVisitor,
+)
 
 error_dict_comprehension = """
     {super().make_key(it): make_value(it) for it in items}

tests/test_visitors/test_ast/test_classes/test_class_attributes/test_shadow_attributes.py

@@ -3,7 +3,9 @@
 from wemake_python_styleguide.violations.oop import (
     ShadowedClassAttributeViolation,
 )
-from wemake_python_styleguide.visitors.ast.classes import ClassAttributeVisitor
+from wemake_python_styleguide.visitors.ast.classes.attributes import (
+    ClassAttributeVisitor,
+)
 
 # Can raise:
 

tests/test_visitors/test_ast/test_classes/test_class_attributes/test_slots_syntax.py

@@ -1,7 +1,9 @@
 import pytest
 
 from wemake_python_styleguide.violations.oop import WrongSlotsViolation
-from wemake_python_styleguide.visitors.ast.classes import WrongSlotsVisitor
+from wemake_python_styleguide.visitors.ast.classes.attributes import (
+    WrongSlotsVisitor,
+)
 
 class_body_template = """
 class ClassWithSlots:

tests/test_visitors/test_ast/test_classes/test_getter_setter.py

@@ -3,7 +3,9 @@
 from wemake_python_styleguide.violations.oop import (
     UnpythonicGetterSetterViolation,
 )
-from wemake_python_styleguide.visitors.ast.classes import WrongClassBodyVisitor
+from wemake_python_styleguide.visitors.ast.classes.classdef import (
+    WrongClassBodyVisitor,
+)
 
 module_getter_and_setter = """
 attribute = 1

tests/test_visitors/test_ast/test_classes/test_lambda_attr_assign.py

@@ -3,7 +3,9 @@
 from wemake_python_styleguide.violations.oop import (
     LambdaAttributeAssignedViolation,
 )
-from wemake_python_styleguide.visitors.ast.classes import ClassAttributeVisitor
+from wemake_python_styleguide.visitors.ast.classes.attributes import (
+    ClassAttributeVisitor,
+)
 
 # Correct:
 

tests/test_visitors/test_ast/test_classes/test_method_order.py

@@ -3,7 +3,7 @@
 from wemake_python_styleguide.violations.consistency import (
     WrongMethodOrderViolation,
 )
-from wemake_python_styleguide.visitors.ast.classes import (
+from wemake_python_styleguide.visitors.ast.classes.methods import (
     ClassMethodOrderVisitor,
 )
 

tests/test_visitors/test_ast/test_classes/test_methods/test_async_magic_methods.py

@@ -1,7 +1,9 @@
 import pytest
 
 from wemake_python_styleguide.violations.oop import AsyncMagicMethodViolation
-from wemake_python_styleguide.visitors.ast.classes import WrongMethodVisitor
+from wemake_python_styleguide.visitors.ast.classes.methods import (
+    WrongMethodVisitor,
+)
 
 sync_method = """
 class Example:

tests/test_visitors/test_ast/test_classes/test_methods/test_async_yield_magic_methods.py

@@ -1,7 +1,9 @@
 import pytest
 
 from wemake_python_styleguide.violations.oop import AsyncMagicMethodViolation
-from wemake_python_styleguide.visitors.ast.classes import WrongMethodVisitor
+from wemake_python_styleguide.visitors.ast.classes.methods import (
+    WrongMethodVisitor,
+)
 
 sync_method = """
 class Example:

tests/test_visitors/test_ast/test_classes/test_methods/test_magic_methods.py

@@ -2,7 +2,9 @@
 
 from wemake_python_styleguide.constants import MAGIC_METHODS_BLACKLIST
 from wemake_python_styleguide.violations.oop import BadMagicMethodViolation
-from wemake_python_styleguide.visitors.ast.classes import WrongMethodVisitor
+from wemake_python_styleguide.visitors.ast.classes.methods import (
+    WrongMethodVisitor,
+)
 
 magic_method = """
 class Example:

tests/test_visitors/test_ast/test_classes/test_methods/test_method_without_arguments.py

@@ -4,7 +4,9 @@
     MethodWithoutArgumentsViolation,
     StaticMethodViolation,
 )
-from wemake_python_styleguide.visitors.ast.classes import WrongMethodVisitor
+from wemake_python_styleguide.visitors.ast.classes.methods import (
+    WrongMethodVisitor,
+)
 
 method_inside_class = """
 class Example:

tests/test_visitors/test_ast/test_classes/test_methods/test_staticmethod.py

@@ -1,7 +1,9 @@
 import pytest
 
 from wemake_python_styleguide.violations.oop import StaticMethodViolation
-from wemake_python_styleguide.visitors.ast.classes import WrongMethodVisitor
+from wemake_python_styleguide.visitors.ast.classes.methods import (
+    WrongMethodVisitor,
+)
 
 decorated_method = """
 class Example:

tests/test_visitors/test_ast/test_classes/test_methods/test_useless_overwriting_method.py

@@ -3,7 +3,9 @@
 import pytest
 
 from wemake_python_styleguide.violations import oop
-from wemake_python_styleguide.visitors.ast.classes import WrongMethodVisitor
+from wemake_python_styleguide.visitors.ast.classes.methods import (
+    WrongMethodVisitor,
+)
 
 regular_method_detailed = """
 class Useless:

tests/test_visitors/test_ast/test_classes/test_methods/test_yield_magic_method.py

@@ -1,7 +1,9 @@
 import pytest
 
 from wemake_python_styleguide.violations.oop import YieldMagicMethodViolation
-from wemake_python_styleguide.visitors.ast.classes import WrongMethodVisitor
+from wemake_python_styleguide.visitors.ast.classes.methods import (
+    WrongMethodVisitor,
+)
 
 method_template = """
 class Test: