[Presubmit] check for single quotes in html properties

chrome/browser/web_dev_style/html_checker.py

 # Copyright 2014 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 for Chromium HTML resources. See chrome/browser/PRESUBMIT.py.
 """
 
 import regex_check
 
@@ skipping 26 matching lines @@
   def DoNotUseInputTypeButtonCheck(self, line_number, line):
     regex = self.input_api.re.compile("""
         (<input [^>]*  # "<input " followed by anything but ">"
         type="button"  # type="button"
         [^>]*>)        # anything but ">" then ">"
         """,
         self.input_api.re.VERBOSE)
     return regex_check.RegexCheck(self.input_api.re, line_number, line, regex,
         'Use the button element instead of <input type="button">')
 
+  def DoNotUseSingleQuotesCheck(self, line_number, line):
+    regex = self.input_api.re.compile("""
+        <\S+                           # The tag name.
+        (?:\s+\S+\$?="[^"]*"|\s+\S+)*  # Correctly quoted or non-value props.
+        \s+(\S+\$?='[^']*')            # Find incorrectly quoted (foo='bar').
+        [^>]*>                         # To the end of the tag.
+        """,
+        self.input_api.re.MULTILINE | self.input_api.re.VERBOSE)
+    return regex_check.RegexCheck(self.input_api.re, line_number, line, regex,
+        'Use double quotes rather than single quotes in HTML properties')
+
   def I18nContentJavaScriptCaseCheck(self, line_number, line):
     regex = self.input_api.re.compile("""
         (?:^|\s)                      # start of line or whitespace
         i18n-content="                # i18n-content="
         ([A-Z][^"]*|[^"]*[-_][^"]*)"  # starts with caps or contains '-' or '_'
         """,
         self.input_api.re.VERBOSE)
     return regex_check.RegexCheck(self.input_api.re, line_number, line, regex,
         "For i18n-content use javaScriptCase.")
 
@@ skipping 29 matching lines @@
             self.LabelCheck(line_number, line),
         ]))
 
       if errors:
         abs_local_path = f.AbsoluteLocalPath()
         file_indicator = 'Found HTML style issues in %s' % abs_local_path
         prompt_msg = file_indicator + '\n\n' + '\n'.join(errors) + '\n'
         results.append(self.output_api.PresubmitPromptWarning(prompt_msg))
 
     return results