Noissue - Avoid access to stack trace unless necessary

polyfill.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 71 matching lines @@
       return;
 
     // If the property is not writable assigning it will fail, so we use
     // Object.defineProperty here instead. Assuming the property isn't
     // inherited its other attributes (e.g. enumerable) are preserved,
     // except for accessor attributes (e.g. get and set) which are discarded
     // since we're specifying a value.
     Object.defineProperty(object, name, {
       value(...args)
       {
-        let callStack = new Error().stack;
-
         if (typeof args[args.length - 1] == "function")
           return func.apply(object, args);
 
         // If the last argument is undefined, we drop it from the list assuming
         // it stands for the optional callback. We must do this, because we have
         // to replace it with our own callback. If we simply append our own
         // callback to the list, it won't match the signature of the function
         // and will cause an exception.
         if (typeof args[args.length - 1] == "undefined")
           args.pop();
 
         let resolvePromise = null;
         let rejectPromise = null;
 

[Sebastian Noack, 2018/09/29 16:07:14]

Nit: This blank line seems redundant.

[Manish Jethani, 2018/09/29 16:39:08]

I'd prefer to keep the variable standing out from the rest as it is clearly only
for debugging purposes. It's easier to notice this way.

+        let callStack = new Error().stack;
+
         func.call(object, ...args, result =>
         {
           let error = browser.runtime.lastError;
           if (error && !portClosedBeforeResponseError.test(error.message))
           {
             // runtime.lastError is already an Error instance on Edge, while on
             // Chrome it is a plain object with only a message property.
             if (!(error instanceof Error))
             {
               error = new Error(error.message);
@@ skipping 113 matching lines @@
 
   // Workaround since HTMLCollection, NodeList, StyleSheetList, and CSSRuleList
   // didn't have iterator support before Chrome 51.
   // https://bugs.chromium.org/p/chromium/issues/detail?id=401699
   for (let object of [HTMLCollection, NodeList, StyleSheetList, CSSRuleList])
   {
     if (!(Symbol.iterator in object.prototype))
       object.prototype[Symbol.iterator] = Array.prototype[Symbol.iterator];
   }
 }