Recreated #1171 (#1183)

* Issue #1111 - Forbid to use \r in line breaks: Made base rule check and test script

* Issue #1111 - Forbid to use \r in line breaks: updated CHANGELOG.md in this case

* Issue #1111 - Forbid to use \r in line breaks: some minor processing

* Issue #1111 - Forbid to use \r in line breaks: some minor processing [step2]

* Issue #1111 - Forbid to use \r in line breaks: some minor processing [step3]

* Issue #1111 ~~~: [step4] 'Repair test' by update WPS-record for new #noqa violation in #/tests/test_checker/test_noqa.py

* Issue #1111 ~~~: [step5] by update WPS-record for new #noqa violation and it Count in #/tests/test_checker/test_noqa.py

* Issue #1111 ~~~: [step6] by update WPS-record for new #noqa violation and chng it's Count to Zero in #/tests/test_checker/test_noqa.py

* Issue #1111 ~~~: [step7] change sort order with CR-newline Violation(code=357) in #/violations/consistency.py

* Issue #1111: fixed logical mistake with if-condition in #/visitors/tokenize/syntax.py

* Issue #1111: add new condition in #/visitors/tokenize/syntax.py

* Issue #1111: add new condition in #/visitors/tokenize/syntax.py

* Issue #1111: add new condition in #/visitors/tokenize/syntax.py

* Issue #1111: removed excess condition with 'line' variable in #/visitors/tokenize/syntax.py

* Issue #1111: add new condition with token.line in #/visitors/tokenize/syntax.py (locally tested OK)

* Fixes build

Co-authored-by: ilia shb <45450122+jigi-33@users.noreply.github.com>

CHANGELOG.md

@@ -29,7 +29,8 @@ Semantic versioning in our case means:
 - Adds domain names options:
   `--allowed-domain-names` and `--forbidden-domain-names`,
   that are used to create variable names' blacklist #1106
-- Forbids to use `:=` operator, it reuses `WPS332` code
+- Forbids to use `\r` (carriage return) as line breaks in strings #1111
+- Forbids to use `:=` operator, it now reuses `WPS332` code
 - Forbids to use positional only `/` arguments
 - Forbids to have too many names imported from a single `from ... import`
 - Adds `__call__` to list of methods that should be on top #1125

tests/test_checker/test_noqa.py

@@ -163,6 +163,7 @@
     'WPS354': 1,
     'WPS355': 1,
     'WPS356': 1,
+    'WPS357': 0,  # logically unacceptable.
 
     'WPS400': 0,  # defined in ignored violations.
     'WPS401': 0,  # logically unacceptable.

tests/test_visitors/test_tokenize/test_consistency/test_string_newlines.py

@@ -0,0 +1,79 @@
+# -*- coding: utf-8 -*-
+
+import pytest
+
+from wemake_python_styleguide.violations.consistency import (
+    LineCompriseCarriageReturnViolation,
+)
+from wemake_python_styleguide.visitors.tokenize.syntax import (
+    WrongKeywordTokenVisitor,
+)
+
+# Correct:
+
+correct_newline = 'print(1)\nprint(2)'
+correct_nl = 'print(1,\n    2)'
+correct_string = '"\r"'
+correct_raw_string = 'r"\r"'
+correct_real_newline = """
+print(1)
+print(2)
+"""
+
+# Wrong:
+
+wrong_newline_single = 'print(1)\r\nprint(2)'
+wrong_newline_sequenced1 = 'print(1)\nprint(2)\r\n'
+wrong_newline_sequenced2 = 'print(1)\r\nprint(2)\n'
+wrong_newline_sequenced3 = 'print(1,\r\n    2)'
+wrong_newline_in_multiline = """print(2)\r
+print(3)
+"""
+
+
+@pytest.mark.parametrize('code', [
+    wrong_newline_single,
+    wrong_newline_sequenced1,
+    wrong_newline_sequenced2,
+    wrong_newline_sequenced3,
+    wrong_newline_in_multiline,
+])
+def test_string_wrong_line_breaks(
+    parse_tokens,
+    assert_errors,
+    default_options,
+    code,
+):
+    """Ensures that obsolete string's line break raise a violation."""
+    file_tokens = parse_tokens(code)
+
+    visitor = WrongKeywordTokenVisitor(
+        default_options, file_tokens=file_tokens,
+    )
+    visitor.run()
+
+    assert_errors(visitor, [LineCompriseCarriageReturnViolation])
+
+
+@pytest.mark.parametrize('code', [
+    correct_newline,
+    correct_nl,
+    correct_string,
+    correct_raw_string,
+    correct_real_newline,
+])
+def test_string_proper_line_breaks(
+    parse_tokens,
+    assert_errors,
+    default_options,
+    code,
+):
+    """Ensures that proper string's line break are fine."""
+    file_tokens = parse_tokens(code)
+
+    visitor = WrongKeywordTokenVisitor(
+        default_options, file_tokens=file_tokens,
+    )
+    visitor.run()
+
+    assert_errors(visitor, [])

wemake_python_styleguide/violations/consistency.py

@@ -82,6 +82,7 @@
    ConsecutiveYieldsViolation
    BracketBlankLineViolation
    IterableUnpackingViolation
+   LineCompriseCarriageReturnViolation
 
 Consistency checks
 ------------------
@@ -143,6 +144,7 @@
 .. autoclass:: ConsecutiveYieldsViolation
 .. autoclass:: BracketBlankLineViolation
 .. autoclass:: IterableUnpackingViolation
+.. autoclass:: LineCompriseCarriageReturnViolation
 
 """
 
@@ -2120,3 +2122,24 @@ class IterableUnpackingViolation(ASTViolation):
 
     error_template = 'Found an unnecessary iterable unpacking'
     code = 356
+
+
+@final
+class LineCompriseCarriageReturnViolation(TokenizeViolation):
+    r"""
+    Forbids to use ``\r`` (carriage return) in line breaks.
+
+    Reasoning:
+        We enforce Unix-style newlines.
+        We only use newlines (``\n``), not carriage returns.
+        So ``\r`` line breaks not allowed in code.
+
+    Solution:
+        Use only ``\n`` (not ``\r\n`` or ``\r``) to break lines.
+
+    .. versionadded:: 0.14.0
+
+    """
+
+    error_template = r'Found a ``\r`` (carriage return) line break'
+    code = 357

wemake_python_styleguide/violations/oop.py

@@ -524,7 +524,9 @@ class UselessOverwrittenMethodViolation(ASTViolation):
 
         # Correct:
         class Test(Base):
-            ...
+            def method(self, argument):
+                super().method(argument)
+                return argument  # or None, or anything!
 
         # Wrong:
         class Test(object):

wemake_python_styleguide/visitors/tokenize/syntax.py

@@ -6,13 +6,19 @@
 from typing_extensions import final
 
 from wemake_python_styleguide.violations.consistency import (
+    LineCompriseCarriageReturnViolation,
     LineStartsWithDotViolation,
     MissingSpaceBetweenKeywordAndParenViolation,
 )
 from wemake_python_styleguide.visitors.base import BaseTokenVisitor
+from wemake_python_styleguide.visitors.decorators import alias
 
 
 @final
+@alias('visit_any_newline', (
+    'visit_newline',
+    'visit_nl',
+))
 class WrongKeywordTokenVisitor(BaseTokenVisitor):
     """Visits keywords and finds violations related to their usage."""
 
@@ -36,6 +42,16 @@ def visit_dot(self, token: tokenize.TokenInfo) -> None:
         """
         self._check_line_starts_with_dot(token)
 
+    def visit_any_newline(self, token: tokenize.TokenInfo) -> None:
+        r"""
+        Checks ``\r`` (carriage return) in line breaks.
+
+        Raises:
+            LineCompriseCarriageReturnViolation
+
+        """
+        self._check_line_comprise_carriage_return(token)
+
     def _check_space_before_open_paren(self, token: tokenize.TokenInfo) -> None:
         if not keyword.iskeyword(token.string):
             return
@@ -49,3 +65,9 @@ def _check_line_starts_with_dot(self, token: tokenize.TokenInfo) -> None:
         line = token.line.lstrip()
         if line.startswith('.') and not line.startswith('...'):
             self.add_violation(LineStartsWithDotViolation(token))
+
+    def _check_line_comprise_carriage_return(
+        self, token: tokenize.TokenInfo,
+    ) -> None:
+        if '\r' in token.string:
+            self.add_violation(LineCompriseCarriageReturnViolation(token))