Warn about suspicious arguments in {bytes,str,unicode}.{l,r,}strip calls. Closes #74013

1  ChangeLog for PyLint
2  ====================
3 
4  --
5 +    * #74013: new E1310[bad-str-strip-call] message warning when a call to a
6 +      {l,r,}strip method contains duplicate characters (patch by Torsten Marek)
7 +
8      * #124660: internal dependencies should not appear in external dependencies
9        report
10 
11      * #124662: fix name error causing crash when symbols are included in output
12        messages

13  # Copyright (c) 2009-2010 Arista Networks, Inc. - James Lingard
14 -# Copyright (c) 2004-2010 LOGILAB S.A. (Paris, FRANCE).
15 +# Copyright (c) 2004-2013 LOGILAB S.A. (Paris, FRANCE).
16 +# Copyright 2012 Google Inc.
17 +#
18  # http://www.logilab.fr/ -- mailto:contact@logilab.fr
19  # This program is free software; you can redistribute it and/or modify it under
20  # the terms of the GNU General Public License as published by the Free Software
21  # Foundation; either version 2 of the License, or (at your option) any later
22  # version.

23  # 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
24  """Checker for string formatting operations.
25  """
26 
27  from logilab import astng
28 +
29  from pylint.interfaces import IASTNGChecker
30  from pylint.checkers import BaseChecker
31  from pylint.checkers import utils
32 
33 

34      """Checks string formatting operations to ensure that the format string
35      is valid and the arguments match the format string.
36      """
37 
38      __implements__ = (IASTNGChecker,)
39 -    name = 'string_format'
40 +    name = 'string'
41      msgs = MSGS
42 
43      def visit_binop(self, node):
44          if node.op != '%':
45              return

46                      self.add_message('E1305', node=node)
47                  elif num_args < required_num_args:
48                      self.add_message('E1306', node=node)
49 
50 
51 +class StringMethodsChecker(BaseChecker):
52 +    __implements__ = (IASTNGChecker,)
53 +    name = 'string'
54 +    msgs = {
55 +        'E1310': ("Suspicious argument in %s.%s call",
56 +                  "bad-str-strip-call",
57 +                  "The argument to a str.{l,r,}strip call contains a"
58 +                  " duplicate character, "),
59 +        }
60 +
61 +    def visit_callfunc(self, node):
62 +        func = utils.safe_infer(node.func)
63 +        if (isinstance(func, astng.BoundMethod)
64 +            and isinstance(func.bound, astng.Instance)
65 +            and func.bound.name in ('str', 'unicode', 'bytes')
66 +            and func.name in ('strip', 'lstrip', 'rstrip')
67 +            and node.args):
68 +            arg = utils.safe_infer(node.args[0])
69 +            if not isinstance(arg, astng.Const):
70 +                return
71 +            if len(arg.value) != len(set(arg.value)):
72 +                self.add_message('E1310', node=node,
73 +                                 args=(func.bound.name, func.name))
74 +
75 +
76 +
77  def register(linter):
78      """required method to auto register this checker """
79      linter.register_checker(StringFormatChecker(linter))
80 +    linter.register_checker(StringMethodsChecker(linter))

81 +"""Suspicious str.strip calls."""
82 +__revision__ = 1
83 +
84 +''.strip('yo')
85 +''.strip()
86 +
87 +u''.strip('http://')
88 +u''.lstrip('http://')
89 +b''.rstrip('http://')

90 +E:  7: Suspicious argument in unicode.strip call
91 +E:  8: Suspicious argument in unicode.lstrip call
92 +E:  9: Suspicious argument in str.rstrip call