Issue 2396 - Add CSS property filter message responder

messageResponder.js

Index: messageResponder.js
diff --git a/messageResponder.js b/messageResponder.js
index a6886cbbe74380c6901224cc87b8d405de5a8da8..5914e85ac9be6852269d6081f401877323259da4 100644
--- a/messageResponder.js
+++ b/messageResponder.js
@@ -25,7 +25,8 @@
   var FilterStorage = require("filterStorage").FilterStorage;
   var FilterNotifier = require("filterNotifier").FilterNotifier;
   var defaultMatcher = require("matcher").defaultMatcher;
-  
+  var CSSRules = require("cssRules").CSSRules;
+
   var filterClasses = require("filterClasses");
   var Filter = filterClasses.Filter;
   var BlockingFilter = filterClasses.BlockingFilter;
@@ -194,13 +195,28 @@
         callback(filter instanceof BlockingFilter);
         break;
       case "filters.get":
+        if (message.what == "cssproperties" && "domain" in message)

[Thomas Greiner, 2015/11/03 10:57:02]

This condition allows the following invalid message to succeed even though it
shouldn't:

{
  what: "cssproperties",
  subscriptionUrl: "http://..."
}

[kzar, 2015/11/03 14:09:51]

Done.

+        {
+          callback(CSSRules.getRulesForDomain(

[Thomas Greiner, 2015/11/03 10:57:02]

Please avoid forcing everything into a single statement. Splitting it up into
several statements gives us not only better readability but also more useful
stack traces in case of errors.

[kzar, 2015/11/03 14:09:51]

I thought it was pretty readable as it was but fair enough, Done.

[Thomas Greiner, 2015/11/03 14:26:01]

Thanks, I appreciate it. It would've even allowed you to break and call the
callback once but that'd be more of a personal preference so I'll leave that up
to you.

e.g.
var filters = [];
if ("domain" in message)
{
  ...
  filters = ...
}
callback(filters);
break;

[kzar, 2015/11/03 15:49:49]

Done.

+            message.domain, message.specificOnly).map(function(filter)

[Thomas Greiner, 2015/11/03 10:57:03]

The content script doesn't know whether it's supposed to request only specific
filters or not.

Currently, that is being determined by the background page right before calling
`ElemHide.getSelectorsByDomain()` (see "get-selectors" message type in
adblockpluschrome/background.js).

[kzar, 2015/11/03 14:09:51]

Done.

+            {
+              return {
+                prefix: filter.selectorPrefix,
+                suffix: filter.selectorSuffix,
+                regexp: filter.regexpString()

[Thomas Greiner, 2015/11/03 10:57:03]

`CSSPropertyFilter.prototype.regexpString` is a string, not a function.

[kzar, 2015/11/03 14:09:51]

Whoops good point, Done.

+              };
+            })
+          );
+          break;
+        }
+
         var subscription = Subscription.fromURL(message.subscriptionUrl);
         if (!subscription)
         {
           callback([]);
           break;
         }
-        
+
         callback(subscription.filters.map(convertFilter));
         break;
       case "filters.importRaw":