feat: implementing the new rule. Build yet to be debugged. Issue #9

adrwes · Feb 24, 2020 · c02aa31 · c02aa31
1 parent 44f757e
commit c02aa31
Showing 1 changed file with 13 additions and 0 deletions.
diff --git a/wemake_python_styleguide/visitors/tokenize/primitives.py b/wemake_python_styleguide/visitors/tokenize/primitives.py
@@ -147,6 +147,8 @@ class WrongStringTokenVisitor(BaseTokenVisitor):
 
     _implicit_raw_strigns: ClassVar[Pattern] = re.compile(r'\\{2}.+')
 
+    _contains_backslash: ClassVar[Pattern] = re.compile(r'\\')
+
     def __init__(self, *args, **kwargs) -> None:
         """Initializes new visitor and saves all docstrings."""
         super().__init__(*args, **kwargs)
@@ -165,12 +167,14 @@ def visit_string(self, token: tokenize.TokenInfo) -> None:
             WrongMultilineStringViolation
             ImplicitRawStringViolation
             WrongUnicodeEscapeViolation
+            RawStringNotNeededViolation
 
         """
         self._check_correct_multiline(token)
         self._check_string_modifiers(token)
         self._check_implicit_raw_string(token)
         self._check_wrong_unicode_escape(token)
+        self._check_unnecessary_raw_string(token)
 
     def _check_correct_multiline(self, token: tokenize.TokenInfo) -> None:
         _, string_def = split_prefixes(token)
@@ -231,6 +235,15 @@ def _check_wrong_unicode_escape(self, token: tokenize.TokenInfo) -> None:
             # character can never be the start of a new backslash escape.
             index += 2
 
+    def _check_unnecessary_raw_string(self, token: tokenize.TokenInfo) -> None:
+        modifiers, string_def = split_prefixes(token)
+
+        if 'r' in modifiers.lower():
+            if not self._contains_backslash.search(string_def):
+                self.add_violation(
+                    RawStringNotNeededViolation(token, text=token.string),
+                )
+
 
 @final
 class WrongStringConcatenationVisitor(BaseTokenVisitor):