Issue 5184 - Support Firefox-specific webRequest types

lib/requestBlocker.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 15 matching lines @@
 const {Prefs} = require("prefs");
 const {checkWhitelisted, getKey} = require("whitelisting");
 const {stringifyURL, extractHostFromFrame, isThirdParty} = require("url");
 const {port} = require("messaging");
 const devtools = require("devtools");
 
 // Chrome and Firefox (WebExtensions) can't distinguish between
 // OBJECT_SUBREQUEST and OBJECT requests.
 RegExpFilter.typeMap.OBJECT_SUBREQUEST = RegExpFilter.typeMap.OBJECT;
 
-let resourceTypes = new Map(
-  Object.keys(RegExpFilter.typeMap).map(type => [type.toLowerCase(), type])
-  .concat([
-    // Map unsupported resource types to types we support. Anything that isn't

[Sebastian Noack, 2017/05/19 17:47:41]

I wouldn't consider these resource types "unsupported", but rather translated
into a more abstract model.

For reference, this is the original mapping in the legacy Gecko extension (which
has more comprehensive comments for the mapped types):
https://hg.adblockplus.org/adblockplus/file/ce08e8e0aabf/lib/contentPolicy.js...

Also I'd wonder what you think about the approach, there, creating the Map from
a generator? I don't have a strong opinion. But if you think it's more readable
you might want to adopt it here.

[Manish Jethani, 2017/05/19 23:44:15]

OK, I've just copied that comment over and changed "Firefox" to "the browser".
Feels like an unnecessary use of a generator, but doesn't hurt and probably not
a bad idea to go for it for consistency. I've made the change.

[Sebastian Noack, 2017/05/20 06:42:37]

As I said, I don't have a strong opinion. So if you'd rather not use a generator
here that is fine too. Though I personally don't like chains of .map() and
.concat() either. And the generator syntax seems to be the approach with the
least boilerplate. But up to you.

[Manish Jethani, 2017/05/20 18:50:47]

Acknowledged.

-    // mapped here is implicitly mapped to "OTHER".
-    ["beacon", "PING"],
-    ["imageset", "IMAGE"],
-    ["sub_frame", "SUBDOCUMENT"]
-  ])
-);
+// Map of content types reported by the browser to the respecitve content types
+// used by Adblock Plus. Other content types are simply mapped to OTHER.
+let resourceTypes = new Map(function*()
+{
+  for (let type in RegExpFilter.typeMap)
+    yield [type.toLowerCase(), type];
+
+  yield ["sub_frame", "SUBDOCUMENT"];
+
+  // Treat navigator.sendBeacon() the same as <a ping>, it's essentially the
+  // same concept - merely generalized.
+  yield ["beacon", "PING"];
+
+  // Treat <img srcset> and <picture> the same as other images.
+  yield ["imageset", "IMAGE"];
+}());
 
 function onBeforeRequestAsync(page, url, type, docDomain,
                               thirdParty, sitekey,
                               specificOnly, filter)
 {
   if (filter)
     FilterNotifier.emit("filter.hitCount", filter, 0, 0, page);
 
   if (devtools)
   {
@@ skipping 120 matching lines @@
   if (msg.requestType in chrome.webRequest.ResourceType)
     return false;
 
   return ext.webRequest.onBeforeRequest._dispatch(
      new URL(msg.url),
      msg.requestType,
      sender.page,
      sender.frame
   ).includes(false);
 });