Fix Raven.js throwing exception when run in Selenium (fixes #495)

src/raven.js

@@ -221,7 +221,14 @@ Raven.prototype = {
         }
 
         // We don't wanna wrap it twice!
-        if (func.__raven__) {
+        try {
+            if (func.__raven__) {
+                return func;
+            }
+        } catch (e) {
+            // Just accessing the __raven__ prop in some Selenium environments
+            // can cause a "Permission denied" exception (see raven-js#495).
+            // Bail on wrapping and return the function as-is (defers to window.onerror).
             return func;
         }
 

test/raven.test.js

@@ -1729,6 +1729,19 @@ describe('Raven (public API)', function() {
             }, error);
         });
 
+        it('should return input funciton as-is if accessing __raven__ prop throws exception', function (){
+            // see raven-js#495
+            var fn = function () {};
+            Object.defineProperty(fn, '__raven__', {
+              get: function () {
+                  throw new Error('Permission denied')
+              }
+            });
+            assert.throw(function () { fn.__raven__; }, 'Permission denied');
+            var wrapped = Raven.wrap(fn);
+            assert.equal(fn, wrapped);
+        });
+
     });
 
     describe('.context', function() {