Prepare Chrome Extensions for ES2015 RegExp semantics

extensions/renderer/resources/binding.js

 // 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.
 
 var Event = require('event_bindings').Event;
 var forEach = require('utils').forEach;
 var GetAvailability = requireNative('v8_context').GetAvailability;
 var exceptionHandler = require('uncaught_exception_handler');
 var lastError = require('lastError');
 var logActivity = requireNative('activityLogger');
@@ skipping 120 matching lines @@
 function getPlatform() {
   var platforms = [
     [/CrOS Touch/, "chromeos touch"],
     [/CrOS/, "chromeos"],
     [/Linux/, "linux"],
     [/Mac/, "mac"],
     [/Win/, "win"],
   ];
 
   for (var i = 0; i < platforms.length; i++) {
-    if ($RegExp.test(platforms[i][0], navigator.appVersion)) {
+    if ($RegExp.exec(platforms[i][0], navigator.appVersion)) {
       return platforms[i][1];
     }
   }
   return "unknown";
 }
 
 function isPlatformSupported(schemaNode, platform) {
   return !schemaNode.platforms ||
       $Array.indexOf(schemaNode.platforms, platform) > -1;
 }
@@ skipping 143 matching lines @@
           var id = $String.substr(t.id, schema.namespace.length + 1);
           mod[id] = {};
           $Array.forEach(enumValues, function(enumValue) {
             // Note: enums can be declared either as a list of strings
             // ['foo', 'bar'] or as a list of objects
             // [{'name': 'foo'}, {'name': 'bar'}].
             enumValue = $Object.hasOwnProperty(enumValue, 'name') ?
                 enumValue.name : enumValue;
             if (enumValue) {  // Avoid setting any empty enums.
               // Make all properties in ALL_CAPS_STYLE.
-              // Replace myEnum-Foo with my_Enum-Foo:
-              var propertyName =
-                  $String.replace(enumValue, /([a-z])([A-Z])/g, '$1_$2');
-              // Replace my_Enum-Foo with my_Enum_Foo:
-              propertyName = $String.replace(propertyName, /\W/g, '_');
               // If the first character is a digit (we know it must be one of

[Devlin, 2016/04/05 19:15:50]

We should add a new comment here explaining why this is so tedious. e.g.

// The built-in versions of $String.replace call other built-ins, which
// may be clobbered. Instead, manually build the property name.

[Dan Ehrenberg, 2016/04/05 20:20:57]

Done

               // a digit, a letter, or an underscore), precede it with an
               // underscore.
-              propertyName = $String.replace(propertyName, /^(\d)/g, '_$1');
+              var propertyName = ($RegExp.exec(/\d/, enumValue[0])) ? '_' : '';
+              for (var i = 0; i < enumValue.length; i++) {

[Devlin, 2016/04/05 19:15:50]

++i

[Dan Ehrenberg, 2016/04/05 20:20:57]

Done

+                if (i > 0 && $RegExp.exec(/[a-z]/, enumValue[i-1]) &&

[Devlin, 2016/04/05 19:15:50]

I think this block would be a little easier to read with something like:
var next = '';
if (...)
  next = '_' + enumValue[i];
else if (...)
  next = '_'
else
  next = enumValue[i];
propertyName += next;

[Dan Ehrenberg, 2016/04/05 20:20:57]

Done

+                    $RegExp.exec(/[A-Z]/, enumValue[i])) {
+                  // Replace myEnum-Foo with my_Enum-Foo:
+                  propertyName = propertyName + '_' + enumValue[i];
+                } else if ($RegExp.exec(/\W/, enumValue[i])) {
+                  // Replace my_Enum-Foo with my_Enum_Foo:
+                  propertyName = propertyName + '_';
+                } else {
+                  propertyName = propertyName + enumValue[i];
+                }
+              }
               // Uppercase (replace my_Enum_Foo with MY_ENUM_FOO):
               propertyName = $String.toUpperCase(propertyName);
               mod[id][propertyName] = enumValue;
             }
           });
         }
       }, this);
     }
 
     // TODO(cduvall): Take out when all APIs have been converted to features.
@@ skipping 194 matching lines @@
                     availability.message);
       return;
     }
 
     this.runHooks_(mod);
     return mod;
   }
 };
 
 exports.$set('Binding', Binding);