Noissue - Explicitly ignore asynchronous errors from tabs.insertCSS

lib/cssInjection.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present 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 58 matching lines @@
 function addStyleSheet(tabId, frameId, styleSheet)
 {
   try
   {
     browser.tabs.insertCSS(tabId, {
       code: styleSheet,
       cssOrigin: "user",
       frameId,
       matchAboutBlank: true,
       runAt: "document_start"
-    });
+    })
+    .catch(() => {});

[Sebastian Noack, 2018/03/12 22:41:25]

To clarify, so the catch-block below is essentially only hit on Firefox, and the
catch-callback is essentially only called on Chromium?

Why is it necessary to filter for error messages that contain "cssOrigin" on
Firefox, but not on Chromium?

[Manish Jethani, 2018/03/13 06:09:47]

On both Firefox and Chrome 65 the error for "cssOrigin" is synchronous, so we're
handling that correctly for both platforms. Additionally, on Chrome 66+ I am
getting the error for "frame not found" (see stack trace) asynchronously. This
is the one that clogs up the log.

We won't be getting the "cssOrigin" error asynchronously because Chrome 66+
doesn't throw that error.

[Sebastian Noack, 2018/03/13 15:38:45]

I see. Perhaps add some comments here, clarifying when we get an asynchronous
error, and when insertCSS() throws synchronously.

[Manish Jethani, 2018/03/13 17:14:20]

Done.

   }
   catch (error)
   {
     if (/\bcssOrigin\b/.test(error.message))
       userStyleSheetsSupported = false;
 
     return false;
   }
 
   return true;
@@ skipping 89 matching lines @@
     response.inlineEmulated = true;
 
   return response;
 });
 
 port.on("elemhide.injectSelectors", (message, sender) =>
 {
   updateFrameStyles(sender.page.id, sender.frame.id, message.selectors,
                     message.groupName);
 });