1// Copyright 2014 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5'use strict'; 6 7/** 8 * This variable is checked in SelectFileDialogExtensionBrowserTest. 9 * @type {number} 10 */ 11window.JSErrorCount = 0; 12 13/** 14 * Counts uncaught exceptions. 15 */ 16window.onerror = function() { window.JSErrorCount++; }; 17 18/** 19 * Wraps the function to use it as a callback. 20 * This does: 21 * - Capture the stack trace in case of error. 22 * - Bind this object 23 * 24 * @param {Object} thisObject Object to be used as this. 25 * @param {...} var_args Arguments to be bound with the wrapped function. 26 * @return {function} Wrapped function. 27 */ 28Function.prototype.wrap = function(thisObject, var_args) { 29 var func = this; 30 var liveStack = (new Error('Stack trace before async call')).stack; 31 if (thisObject === undefined) 32 thisObject = null; 33 var boundArguments = Array.prototype.slice.call(arguments, 1); 34 35 return function wrappedCallback(var_args) { 36 try { 37 var args = boundArguments.concat(Array.prototype.slice.call(arguments)); 38 return func.apply(thisObject, args); 39 } catch (e) { 40 // Some async funcrtion doesn't handle exception correctly. So outputing 41 // the exception message and stack trace just in case. 42 // The message will show twice if the caller handles exception correctly. 43 console.error(e.stack); 44 console.info('Exception above happened in callback.', liveStack); 45 46 window.JSErrorCount++; 47 throw e; 48 } 49 } 50}; 51