Added a spelling checker.

New messages:
- wrong-spelling-in-comment
- wrong-spelling-in-docstring
New options:
- spelling-dict
- spelling-ignore-words
New dependency: python-enchant (added as suggested in deb package).

2 files changed, 151 insertions, 1 deletions

diff --git a/checkers/spelling.py b/checkers/spelling.py
new file mode 100644
index 0000000..ec0a147
--- /dev/null
+++ b/checkers/spelling.py
@@ -0,0 +1,150 @@
+# Copyright 2014 Michal Nowikowski.
+#
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation; either version 2 of the License, or (at your option) any later
+# version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details
+#
+# You should have received a copy of the GNU General Public License along with
+# this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+"""Checker for spelling errors in comments and docstrings.
+"""
+
+import sys
+import tokenize
+import string
+import re
+
+import astroid
+
+from pylint.interfaces import ITokenChecker, IAstroidChecker, IRawChecker
+from pylint.checkers import BaseChecker, BaseTokenChecker
+from pylint.checkers import utils
+from pylint.checkers.utils import check_messages
+
+try:
+    import enchant
+except ImportError:
+    enchant = None
+
+if enchant is not None:
+    br = enchant.Broker()
+    dicts = br.list_dicts()
+    dict_choices = [''] + [d[0] for d in dicts]
+    dicts = ["%s (%s)" % (d[0], d[1].name) for d in dicts]
+    dicts = ", ".join(dicts)
+    instr = ""
+else:
+    dicts = "none"
+    dict_choices = ['']
+    instr = " To make it working install python-enchant package."
+
+table = string.maketrans("", "")
+
+class SpellingInCommentsChecker(BaseTokenChecker):
+    """Check spelling in comments"""
+    __implements__ = (ITokenChecker, IAstroidChecker)
+    name = 'spelling'
+    msgs = {
+        'C8402': ('Wrong spelling of a word \'%s\' in a comment:\n%s\n%s\nDid you mean: \'%s\'?',
+                  'wrong-spelling-in-comment',
+                  'Used when a word in comment is not spelled correctly.'),
+        'C8403': ('Wrong spelling of a word \'%s\' in a docstring:\n%s\n%s\nDid you mean: \'%s\'?',
+                  'wrong-spelling-in-docstring',
+                  'Used when a word in docstring is not spelled correctly.'),
+        }
+    options = (('spelling-dict',
+                {'default' : '', 'type' : 'choice', 'metavar' : '<dict name>',
+                 'choices': dict_choices,
+                 'help' : 'Spelling dictionary name. Available dictionaries: %s.%s' % (dicts, instr)}),
+               ('spelling-ignore-words',
+                {'default' : '', 'type' : 'string', 'metavar' : '<comma separated words>',
+                 'help' : 'List of comma separated words that should not be checked.'}),
+                 )
+
+    def open(self):
+        self.initialized = False
+
+        if enchant is None:
+            return
+
+        dict_name = self.config.spelling_dict
+        if not dict_name:
+            return
+
+        self.ignore_list = self.config.spelling_ignore_words.split(",")
+        self.spelling_dict = enchant.Dict(dict_name)
+
+        puncts = string.punctuation.replace("'", "")
+        self.regex = re.compile('[%s]' % re.escape(puncts))
+
+        self.initialized = True
+
+    def process_tokens(self, tokens):
+        if not self.initialized:
+            return
+
+        # process tokens and look for comments
+        for (tok_type, token, (start_row, start_col), _, _) in tokens:
+            if tok_type == tokenize.COMMENT:
+                # replace punctuation signs with space: e.g. and/or -> and or
+                comment = self.regex.sub(' ', token)
+
+                # go through words and check them
+                for w in comment.split():
+                    if not w in self.ignore_list and not self.spelling_dict.check(w):
+                        suggestions = self.spelling_dict.suggest(w)[:4]
+                        col = token.index(w)
+                        indicator = (" " * col) + ("^" * len(w))
+                        self.add_message('wrong-spelling-in-comment', line=start_row,
+                                         args=(w, token, indicator, "' or '".join(suggestions)))
+
+    @check_messages('wrong-spelling-in-docstring')
+    def visit_module(self, node):
+        if not self.initialized:
+            return
+        self._check_docstring(node)
+
+    @check_messages('wrong-spelling-in-docstring')
+    def visit_class(self, node):
+        if not self.initialized:
+            return
+        self._check_docstring(node)
+
+    @check_messages('wrong-spelling-in-docstring')
+    def visit_function(self, node):
+        if not self.initialized:
+            return
+        self._check_docstring(node)
+
+    def _check_docstring(self, node):
+        """check the node has any spelling errors"""
+        docstring = node.doc
+        if not docstring:
+            return
+
+        start_line = node.lineno + 1
+
+        # go through lines of docstring
+        for idx, line in enumerate(docstring.splitlines()):
+            # replace punctuation signs with space: e.g. and/or -> and or
+            line2 = self.regex.sub(' ', line.strip())
+
+            # go through words in a line and check them
+            for w in line2.split():
+                if not w in self.ignore_list and not self.spelling_dict.check(w):
+                    suggestions = self.spelling_dict.suggest(w)[:4]
+                    col = line.index(w)
+                    indicator = (" " * col) + ("^" * len(w))
+                    self.add_message('wrong-spelling-in-docstring', line=start_line + idx,
+                                     args=(w, line, indicator, "' or '".join(suggestions)))
+
+
+def register(linter):
+    """required method to auto register this checker """
+    linter.register_checker(SpellingInCommentsChecker(linter))
diff --git a/debian/control b/debian/control
index da0c1d1..660eda1 100644
--- a/debian/control
+++ b/debian/control
@@ -20,7 +20,7 @@ Depends: ${python:Depends},
          ${misc:Depends},
 	 python-logilab-common (>= 0.53.0),
 	 python-astroid (>= 1.2)
-Suggests: python-tk
+Suggests: python-tk, python-enchant
 XB-Python-Version: ${python:Versions}
 Description: python code static checker and UML diagram generator
  Pylint is a Python source code analyzer which looks for programming