| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // Handles uncaught exceptions thrown by extensions. By default this is to |
| // log an error message, but tests may override this behaviour. |
| var handler = function(message, e) { |
| console.error(message); |
| }; |
| |
| /** |
| * Formats the error message and invokes the error handler. |
| * |
| * @param {string} message - Error message prefix. |
| * @param {Error|*} e - Thrown object. |
| * @param {string=} priorStackTrace - Error message suffix. |
| * @see formatErrorMessage |
| */ |
| function handle(message, e, priorStackTrace) { |
| message = formatErrorMessage(message, e, priorStackTrace); |
| handler(message, e); |
| } |
| |
| // Runs a user-supplied callback safely. |
| function safeCallbackApply(name, request, callback, args) { |
| try { |
| $Function.apply(callback, request, args); |
| } catch (e) { |
| handle('Error in response to ' + name, e, request.stack); |
| } |
| } |
| |
| /** |
| * Append the error description and stack trace to |message|. |
| * |
| * @param {string} message - The prefix of the error message. |
| * @param {Error|*} e - The thrown error object. This object is potentially |
| * unsafe, because it could be generated by an extension. |
| * @param {string=} priorStackTrace - The stack trace to be appended to the |
| * error message. This stack trace must not include stack frames of |e.stack|, |
| * because both stack traces are concatenated. Overlapping stack traces will |
| * confuse extension developers. |
| * @return {string} The formatted error message. |
| */ |
| function formatErrorMessage(message, e, priorStackTrace) { |
| if (e) |
| message += ': ' + safeErrorToString(e, false); |
| |
| var stack; |
| try { |
| // If the stack was set, use it. |
| // |e.stack| could be void in the following common example: |
| // throw "Error message"; |
| stack = $String.self(e && e.stack); |
| } catch (e) {} |
| |
| // If a stack is not provided, capture a stack trace. |
| if (!priorStackTrace && !stack) |
| stack = getStackTrace(); |
| |
| stack = filterExtensionStackTrace(stack); |
| if (stack) |
| message += '\n' + stack; |
| |
| // If an asynchronouse stack trace was set, append it. |
| if (priorStackTrace) |
| message += '\n' + priorStackTrace; |
| |
| return message; |
| } |
| |
| function filterExtensionStackTrace(stack) { |
| if (!stack) |
| return ''; |
| // Remove stack frames in the stack trace that weren't associated with the |
| // extension, to not confuse extension developers with internal details. |
| stack = $String.split(stack, '\n'); |
| stack = $Array.filter(stack, function(line) { |
| return $String.indexOf(line, 'chrome-extension://') >= 0; |
| }); |
| return $Array.join(stack, '\n'); |
| } |
| |
| function getStackTrace() { |
| var e = {}; |
| $Error.captureStackTrace(e, getStackTrace); |
| return e.stack; |
| } |
| |
| function getExtensionStackTrace() { |
| return filterExtensionStackTrace(getStackTrace()); |
| } |
| |
| /** |
| * Convert an object to a string. |
| * |
| * @param {Error|*} e - A thrown object (possibly user-supplied). |
| * @param {boolean=} omitType - Whether to try to serialize |e.message| instead |
| * of |e.toString()|. |
| * @return {string} The error message. |
| */ |
| function safeErrorToString(e, omitType) { |
| try { |
| return $String.self(omitType && e.message || e); |
| } catch (e) { |
| // This error is exceptional and could be triggered by |
| // throw {toString: function() { throw 'Haha' } }; |
| return '(cannot get error message)'; |
| } |
| } |
| |
| exports.$set('handle', handle); |
| |
| // |newHandler| A function which matches |handler|. |
| exports.$set('setHandler', function(newHandler) { |
| handler = newHandler; |
| }); |
| |
| exports.$set('safeCallbackApply', safeCallbackApply); |
| exports.$set('getStackTrace', getStackTrace); |
| exports.$set('getExtensionStackTrace', getExtensionStackTrace); |
| exports.$set('safeErrorToString', safeErrorToString); |