Add a presubmit check for element.$.localId

chrome/browser/web_dev_style/js_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 JS resources.
 
 See chrome/browser/PRESUBMIT.py
 """
 
 import regex_check
@@ skipping 37 matching lines @@
     """Checks for use of 'document.getElementById' instead of '$'."""
     return self.RegexCheck(i, line, r"(document\.getElementById)\('",
         "Use $('id') or getSVGElement('id') from chrome://resources/js/util.js "
         "instead of document.getElementById('id')")
 
   def InheritDocCheck(self, i, line):
     """Checks for use of '@inheritDoc' instead of '@override'."""
     return self.RegexCheck(i, line, r"\* (@inheritDoc)",
         "@inheritDoc is deprecated, use @override instead")
 
+  def PolymerLocalIdCheck(self, i, line):
+    """Checks for use of element.$.localId."""
+    return self.RegexCheck(i, line, r"(?<!this)(\.\$)[\[\.]",
+        "Please only use this.$.localId, not element.$.localId")
+
   def WrapperTypeCheck(self, i, line):
     """Check for wrappers (new String()) instead of builtins (string)."""
     return self.RegexCheck(i, line,
         r"(?:/\*)?\*.*?@(?:param|return|type) ?"     # /** @param/@return/@type
         r"{[^}]*\b(String|Boolean|Number)\b[^}]*}",  # {(Boolean|Number|String)}
         "Don't use wrapper types (i.e. new String() or @type {String})")
 
   def VarNameCheck(self, i, line):
     """See the style guide. http://goo.gl/uKir6"""
     return self.RegexCheck(i, line,
@@ skipping 153 matching lines @@
       # * the 'const' keyword
       # * Passing an empty array to 'chrome.send()'
       for i, line in enumerate(f.NewContents(), start=1):
         error_lines += filter(None, [
             self.ChromeSendCheck(i, line),
             self.ConstCheck(i, line),
             self.GetElementByIdCheck(i, line),
             self.EndJsDocCommentCheck(i, line),
             self.ExtraDotInGenericCheck(i, line),
             self.InheritDocCheck(i, line),
+            self.PolymerLocalIdCheck(i, line),
             self.WrapperTypeCheck(i, line),
             self.VarNameCheck(i, line),
         ])
 
       # Use closure linter to check for several different errors.
       lint_errors = self.ClosureLint(self.input_api.os_path.join(
           self.input_api.change.RepositoryRoot(), f.LocalPath()))
 
       for error in lint_errors:
         highlight = self._GetErrorHighlight(
@@ skipping 13 matching lines @@
         results.append(self._MakeErrorOrWarning(
             '\n'.join(error_lines), f.AbsoluteLocalPath()))
 
     if results:
       results.append(self.output_api.PresubmitNotifyResult(
           'See the JavaScript style guide at '
           'http://www.chromium.org/developers/web-development-style-guide'
           '#TOC-JavaScript'))
 
     return results