Adds type: comment validation

CHANGELOG.md

@@ -14,7 +14,7 @@ We used to have incremental versioning before `0.1.0`.
 - Adds `--i-control-code` option to ignore `InitModuleHasLogicViolation`
 - Adds check for underscored numbers
 - Forbids `u''` strings
-- Adds `flake8`, `noqa`, and `type` comments check
+- Adds `noqa` and `type` comments checks
 
 ### Misc
 

tests/test_visitors/test_tokenize/test_wrong_comments/test_noqa_comment.py

@@ -14,7 +14,9 @@
     'x = 10_00  # noqa: Z002, Z114',
     'wallet = 10_00  # noqa: Z002',
     'x = 1000  # noqa: Z002',
+    'x = 1000  # noqa:  Z002  ',
     'print(12 + 3)  # regular comment',
+    'print(12 + 3)  #',
     'print(12 + 3)',
     '',
 ])
@@ -35,6 +37,7 @@ def test_correct_comments(
 
 @pytest.mark.parametrize('code', [
     'x = 10_00  # noqa',
+    'x = 10_00  #   noqa   ',
     'x = 10_00 #noqa',
     'x = 10_00#noqa',
     'wallet = 10_00  # noqa: some comments',

tests/test_visitors/test_tokenize/test_wrong_comments/test_typed_ast.py

@@ -0,0 +1,59 @@
+# -*- coding: utf-8 -*-
+
+import pytest
+
+from wemake_python_styleguide.visitors.tokenize.wrong_comments import (
+    WrongCommentVisitor,
+    WrongMagicCommentViolation,
+)
+
+
+@pytest.mark.parametrize('code', [
+    '1 + "12"  # type: ignore',
+    '1 + "12"  # type:ignore',
+    'total = 1000  # type is not clear',
+    'print(12 + 3)  # regular comment',
+    'print(12 + 3)  #',
+    'print(12 + 3)',
+    '',
+])
+def test_correct_comments(
+    parse_tokens,
+    assert_errors,
+    default_options,
+    code,
+):
+    """Ensures that correct comments do not raise a warning."""
+    file_tokens = parse_tokens(code)
+
+    visitor = WrongCommentVisitor(default_options, file_tokens=file_tokens)
+    visitor.run()
+
+    assert_errors(visitor, [])
+
+
+@pytest.mark.parametrize('code', [
+    'total = 1000  # type: int',
+    'total = 1000  # type:int',
+    'total = 1000 # type: int  ',
+    'total = 1000#type:int',
+    'numbs = [1, 2, 3]  # type: missing',
+    'numbs = [1, 2, 3]  # type: List[int]',
+    'numbs = [1, 2, 3]  # type: List["int"]',
+    "numbs = [1, 2, 3]  # type: List['int']",
+    'field = SomeField()  # type: drf.Field',
+    '# type: fixme',
+])
+def test_incorrect_noqa_comment(
+    parse_tokens,
+    assert_errors,
+    default_options,
+    code,
+):
+    """Ensures that incorrect `type` comments raise a warning."""
+    file_tokens = parse_tokens(code)
+
+    visitor = WrongCommentVisitor(default_options, file_tokens=file_tokens)
+    visitor.run()
+
+    assert_errors(visitor, [WrongMagicCommentViolation])

wemake_python_styleguide/constants.py

@@ -100,7 +100,8 @@
 
 #: List of nested classes' names we allow to use.
 NESTED_CLASSES_WHITELIST = frozenset((
-    'Meta',
+    'Meta',  # django forms, models, drf, etc
+    'Params',  # factoryboy specific
 ))
 
 #: List of nested functions' names we allow to use.

wemake_python_styleguide/errors/tokens.py

@@ -72,14 +72,11 @@ class WrongMagicCommentViolation(SimpleStyleViolation):
     We do not allow to use:
 
     1. ``# noqa`` comment without specified errors
-    2. ``# flake8: noqa`` comment to disable the whole file
-    3. ``type: some_type`` comments to specify a type for ``typed_ast``
+    2. ``type: some_type`` comments to specify a type for ``typed_ast``
 
     Reasoning:
         We cover several different use-cases in a single rule.
         ``# noqa`` comment is restricted because it can hide other errors.
-        ``# flake8: noqa`` is restricted because it is hard to tell
-        what files are ignored with this comment.
         ``type: int`` comment is restricted because
         we can already use type annotations instead.
 

wemake_python_styleguide/visitors/tokenize/wrong_comments.py

@@ -22,23 +22,40 @@
 from wemake_python_styleguide.visitors.base import BaseTokenVisitor
 
 NOQA_CHECK: Pattern = re.compile(r'^noqa:?($|[A-Z\d\,\s]+)')
+TYPE_CHECK: Pattern = re.compile(r'^type:\s?([\w\d\[\]\'\"\.]+)$')
 
 
 class WrongCommentVisitor(BaseTokenVisitor):
     """Checks comment tokens."""
 
+    def _get_comment_text(self, token: tokenize.TokenInfo) -> str:
+        return token.string[1:].strip()
+
     def _check_noqa(self, token: tokenize.TokenInfo) -> None:
-        comment_text = token.string[1:].strip()
+        comment_text = self._get_comment_text(token)
         match: Match = NOQA_CHECK.match(comment_text)
         if not match:
             return
 
         excludes = match.groups()[0].strip()
         if not excludes:
             # We can not pass the actual line here,
-            # since it will be ignored due to `noqa` comment:
+            # since it will be ignored due to `# noqa` comment:
             self.add_error(WrongMagicCommentViolation(text=comment_text))
 
+    def _check_typed_ast(self, token: tokenize.TokenInfo) -> None:
+        comment_text = self._get_comment_text(token)
+        match: Match = TYPE_CHECK.match(comment_text)
+        if not match:
+            return
+
+        declared_type = match.groups()[0].strip()
+        if declared_type != 'ignore':
+            self.add_error(
+                WrongMagicCommentViolation(token, text=comment_text),
+            )
+
     def visit_comment(self, token: tokenize.TokenInfo) -> None:
         """Performs comment checks."""
         self._check_noqa(token)
+        self._check_typed_ast(token)