Disable bad-docstring-quotes for <= 3.7 (pylint-dev#5526)

In python 3.7 and below, the ast parser might return wrong line numbers.

Closes pylint-dev#3077

Co-authored-by: Daniël van Noord <[email protected]>

Author: kasium

ChangeLog

@@ -184,6 +184,11 @@ Release date: TBA
 
   Closes #5460
 
+* Disable checker ``bad-docstring-quotes`` for Python <= 3.7, because in these versions the line
+  numbers for decorated functions and classes are not reliable which interferes with the checker.
+
+  Closes #3077
+
 * Fixed incorrect classification of Numpy-style docstring as Google-style docstring for
   docstrings with property setter documentation.
   Docstring classification is now based on the highest amount of matched sections instead

doc/whatsnew/2.13.rst

@@ -38,6 +38,13 @@ Extensions
     Docstring classification is now based on the highest amount of matched sections instead
     of the order in which the docstring styles were tried.
 
+* ``DocStringStyleChecker``
+
+    * Disable checker ``bad-docstring-quotes`` for Python <= 3.7, because in these versions the line
+      numbers for decorated functions and classes are not reliable which interferes with the checker.
+
+      Closes #3077
+
 Other Changes
 =============
 

pylint/extensions/docstyle.py

@@ -17,6 +17,7 @@
 
 from pylint import checkers
 from pylint.checkers.utils import check_messages
+from pylint.constants import PY38_PLUS
 from pylint.interfaces import HIGH, IAstroidChecker
 
 if TYPE_CHECKING:
@@ -33,7 +34,8 @@ class DocStringStyleChecker(checkers.BaseChecker):
         "C0198": (
             'Bad docstring quotes in %s, expected """, given %s',
             "bad-docstring-quotes",
-            "Used when a docstring does not have triple double quotes.",
+            "Used when a docstring does not have triple double quotes. "
+            "This checker only works on Python 3.8+.",
         ),
         "C0199": (
             "First line empty in %s docstring",
@@ -81,7 +83,7 @@ def _check_docstring(self, node_type, node):
                 quotes = "'"
             else:
                 quotes = False
-            if quotes:
+            if quotes and PY38_PLUS:
                 self.add_message(
                     "bad-docstring-quotes",
                     node=node,

tests/functional/ext/docstyle/docstyle.txt

@@ -0,0 +1,22 @@
+"""Checks of Dosctrings 'docstring-first-line-empty'"""
+# pylint: disable=too-few-public-methods,bad-docstring-quotes
+
+def check_messages(*messages):  # [docstring-first-line-empty]
+    """
+    docstring"""
+    return messages
+
+
+def function2():
+    """Test Ok"""
+
+
+class FFFF:  # [docstring-first-line-empty]
+    """
+    Test Docstring First Line Empty
+    """
+
+    def method1(self):  # [docstring-first-line-empty]
+        '''
+        Test Triple Single Quotes docstring
+        '''

tests/functional/ext/docstyle/docstyle_first_line_empty.py

@@ -0,0 +1,3 @@
+docstring-first-line-empty:4:0:7:19:check_messages:First line empty in function docstring:HIGH
+docstring-first-line-empty:14:0:22:11:FFFF:First line empty in class docstring:HIGH
+docstring-first-line-empty:19:4:22:11:FFFF.method1:First line empty in method docstring:HIGH

tests/functional/ext/docstyle/docstyle.rc renamed to tests/functional/ext/docstyle/docstyle_first_line_empty.rc

@@ -0,0 +1,35 @@
+"""Checks of Dosctrings 'bad-docstring-quotes'
+
+Check that the checker is not enabled on python <= 3.7
+"""
+# pylint: disable=docstring-first-line-empty,missing-class-docstring, undefined-variable
+
+
+class FFFF:
+    def method1(self):
+        '''
+        Test Triple Single Quotes docstring
+        '''
+
+    def method2(self):
+        "bad docstring 1"
+
+    def method3(self):
+        'bad docstring 2'
+
+    def method4(self):
+        ' """bad docstring 3 '
+
+    @check_messages("bad-open-mode", "redundant-unittest-assert", "deprecated-module")
+    def method5(self):
+        """Test OK 1 with decorators"""
+
+    def method6(self):
+        r"""Test OK 2 with raw string"""
+
+    def method7(self):
+        u"""Test OK 3 with unicode string"""
+
+
+def function2():
+    """Test Ok"""

tests/functional/ext/docstyle/docstyle_first_line_empty.txt

@@ -0,0 +1,5 @@
+[MASTER]
+load-plugins=pylint.extensions.docstyle,
+
+[testoptions]
+max_pyver=3.7

tests/functional/ext/docstyle/docstyle_quotes_py37.py

@@ -1,22 +1,9 @@
-"""Checks of Dosctrings 'docstring-first-line-empty' 'bad-docstring-quotes'"""
+"""Checks of Dosctrings 'bad-docstring-quotes'"""
+# pylint: disable=docstring-first-line-empty,missing-class-docstring, undefined-variable
 
 
-def check_messages(*messages):  # [docstring-first-line-empty]
-    """
-    docstring"""
-    return messages
-
-
-def function2():
-    """Test Ok"""
-
-
-class FFFF:  # [docstring-first-line-empty]
-    """
-    Test Docstring First Line Empty
-    """
-
-    def method1(self):  # [docstring-first-line-empty, bad-docstring-quotes]
+class FFFF:
+    def method1(self):  # [bad-docstring-quotes]
         '''
         Test Triple Single Quotes docstring
         '''
@@ -39,3 +26,7 @@ def method6(self):
 
     def method7(self):
         u"""Test OK 3 with unicode string"""
+
+
+def function2():
+    """Test Ok"""

tests/functional/ext/docstyle/docstyle_quotes_py37.rc

@@ -0,0 +1,5 @@
+[MASTER]
+load-plugins=pylint.extensions.docstyle,
+
+[testoptions]
+min_pyver=3.8

tests/functional/ext/docstyle/docstyle.py renamed to tests/functional/ext/docstyle/docstyle_quotes_py38.py

@@ -0,0 +1,4 @@
+bad-docstring-quotes:6:4:9:11:FFFF.method1:"Bad docstring quotes in method, expected """""", given '''":HIGH
+bad-docstring-quotes:11:4:12:25:FFFF.method2:"Bad docstring quotes in method, expected """""", given """:HIGH
+bad-docstring-quotes:14:4:15:25:FFFF.method3:"Bad docstring quotes in method, expected """""", given '":HIGH
+bad-docstring-quotes:17:4:18:30:FFFF.method4:"Bad docstring quotes in method, expected """""", given '":HIGH