web_dev_style: allow 0ms or 0s while we hash out the breakage of crbug.com/454776

chrome/browser/web_dev_style/css_checker.py

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Presubmit script for Chromium WebUI resources.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details about the presubmit API built into depot_tools, and see
 http://www.chromium.org/developers/web-development-style-guide for the rules
 we're checking against here.
@@ skipping 240 matching lines @@
     webkit_before_or_after_reg = re.compile(r'-webkit-(\w+-)(after|before):')
 
     def suggest_top_or_bottom(line):
       prop, pos = webkit_before_or_after_reg.search(line).groups()
       top_or_bottom = 'top' if pos == 'before' else 'bottom'
       return ' (replace with %s)' % (prop + top_or_bottom)
 
     def webkit_before_or_after(line):
       return webkit_before_or_after_reg.search(line)
 
-    def zero_length_values(contents):
+    def zero_width_lengths(contents):
       hsl_reg = re.compile(r"""
           hsl\([^\)]*       # hsl(<maybe stuff>
           (?:[, ]|(?<=\())  # a comma or space not followed by a (
           (?:0?\.?)?0%      # some equivalent to 0%""",
           re.VERBOSE)
       zeros_reg = re.compile(r"""
-          ^.*(?:^|[^0-9.])                                 # start/non-number
-          (?:\.0|0(?:\.0?                                  # .0, 0, or 0.0
-          |px|em|%|in|cm|mm|pc|pt|ex|deg|g?rad|m?s|k?hz))  # a length unit

[Dan Beam, 2015/02/03 16:09:16]

this is the functional change

-          (?:\D|$)                                         # non-number/end
-          (?=[^{}]+?}).*$                                  # only { rules }""",
+          ^.*(?:^|[^0-9.])              # start/non-number
+          (?:\.0|0(?:\.0?               # .0, 0, or 0.0
+          |px|em|%|in|cm|mm|pc|pt|ex))  # a length unit
+          (?:\D|$)                      # non-number/end
+          (?=[^{}]+?}).*$               # only { rules }""",
           re.MULTILINE | re.VERBOSE)
       errors = []
       for z in re.finditer(zeros_reg, contents):
         first_line = z.group(0).strip().splitlines()[0]
         if not hsl_reg.search(first_line):
           errors.append('    ' + first_line)
       return errors
 
     # NOTE: Currently multi-line checks don't support 'after'. Instead, add
     # suggestions while parsing the file so another pass isn't necessary.
@@ skipping 46 matching lines @@
           'multiline': True,
         },
         { 'desc': 'Use rgb() over #hex when not a shade of gray (like #333).',
           'test': rgb_if_not_gray,
           'after': suggest_rgb_from_hex,
         },
         { 'desc': 'Use *-top/bottom instead of -webkit-*-before/after.',
           'test': webkit_before_or_after,
           'after': suggest_top_or_bottom,
         },
-        { 'desc': 'Make all zero length terms (i.e. 0px) 0 unless inside of '
-                  'hsl() or part of @keyframe.',
-          'test': zero_length_values,
+        { 'desc': 'Use "0" for zero-width lengths (i.e. 0px -> 0)',
+          'test': zero_width_lengths,
           'multiline': True,
         },
     ]
 
     results = []
     affected_files = self.input_api.AffectedFiles(include_deletes=False,
                                                   file_filter=self.file_filter)
     files = []
     for f in affected_files:
       # Remove all /*comments*/, @at-keywords, and grit <if|include> tags; we're
@@ skipping 31 matching lines @@
             '%s:\n%s' % (f[0], '\n\n'.join(file_errors))))
 
     if results:
       # Add your name if you're here often mucking around in the code.
       authors = ['dbeam@chromium.org']
       results.append(self.output_api.PresubmitNotifyResult(
           'Was the CSS checker useful? Send feedback or hate mail to %s.' %
           ', '.join(authors)))
 
     return results