Only apply author pattern checks when necessary

If we're configured to allow all author patterns (`''` or `.*`), there's
no need to compile and apply our regular expression check.

CHANGES.rst

@@ -1,6 +1,12 @@
 Changes
 =======
 
+1.1.2 (2017-01-12)
+------------------
+
+* Only apply the author regular expression pattern check when a pattern has
+  actually been configured.
+
 1.1.1 (2016-11-06)
 ------------------
 

README.rst

@@ -67,6 +67,7 @@ Configuration values are specified in the ``[flake8]`` section of your `config
 file`_ or as command line arguments (e.g. ``--author-attribute=required``).
 
 - ``author-attribute``: "optional", "required", "forbidden" (default: optional)
-- ``author-pattern``: ``__author__`` validation pattern (default: ``.*``)
+- ``author-pattern``: ``__author__`` validation `re`_ pattern (default: ``''``)
 
 .. _config file: http://flake8.pycqa.org/en/latest/user/configuration.html
+.. _re: https://docs.python.org/library/re.html

flake8_author.py

@@ -11,7 +11,7 @@
 import re
 
 __author__ = 'Jon Parise'
-__version__ = '1.1.1'
+__version__ = '1.1.2'
 
 
 class Checker(object):
@@ -45,7 +45,7 @@ def add_options(cls, parser):
             **extra_kwargs)
         parser.add_option(
             '--author-pattern',
-            default=r'.*',
+            default=r'',
             help="__author__ attribute validation pattern (regex)",
             **extra_kwargs)
 
@@ -59,11 +59,15 @@ def parse_options(cls, options):
                     options.author_attribute,
                     ', '.join(cls.attribute_choices)))
 
-        try:
-            cls.options['pattern'] = re.compile(options.author_pattern)
-        except re.error as e:
-            raise ValueError("author-pattern: '{0}': {1}".format(
-                options.author_pattern, e))
+        # Only build a regular expression object when we've been configured
+        # with a pattern that doesn't match all strings. This naively just
+        # checks for the default empty pattern string as well as `.*`.
+        if options.author_pattern and options.author_pattern != '.*':
+            try:
+                cls.options['pattern'] = re.compile(options.author_pattern)
+            except re.error as e:
+                raise ValueError("author-pattern: '{0}': {1}".format(
+                    options.author_pattern, e))
 
     def find_author_node(self, tree):
         for node in tree.body:
@@ -85,7 +89,8 @@ def run(self):
             message = 'A401 __author__ attributes are not allowed'
             yield node.lineno, node.col_offset, message, type(self)
 
-        elif node and not self.options['pattern'].match(node.value.s):
+        elif (node and 'pattern' in self.options and
+                not self.options['pattern'].match(node.value.s)):
             message = ('A402 __author__ value "{0}" does not match "{1}"'
                        .format(node.value.s, self.options['pattern'].pattern))
             yield node.lineno, node.col_offset, message, type(self)

tests/test_checker.py

@@ -57,6 +57,7 @@ def test_author_invalid_attribute(self):
     def test_author_pattern(self):
         author = 'Jon Parise <jon@example.com>'
         self.assertIsNone(check(author))
+        self.assertIsNone(check(author, pattern=r''))
         self.assertIsNone(check(author, pattern=r'.*'))
 
     def test_author_pattern_not_matched(self):