remoting/webapp/base/js/callstack.js

   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 /** @suppress {duplicate} */
   8 var base = base || {};
   9
  10 /**
  11  * A single stack-frame describing a call-site.
  12  *
  13  *   fn:     The calling function.
  14  *   url:    URL component of the file name. For extensions, this will typically
  15  *           be chrome-extension://<id>
  16  *   file:   The file containing the calling function.
  17  *   line:   The line number.
  18  *   column: The column number.
  19  *
  20  * @typedef {{
  21  *   fn: string,
  22  *   url: string,
  23  *   file: string,
  24  *   line: number,
  25  *   column: number
  26  * }}
  27  */
  28 base.StackFrame;
  29
  30
  31 (function() {
  32
  33 /**
  34  * @param {Error=} opt_error If present, an Error object from which to extract
  35  *     the callstack; if not specified, the current callstack (excluding this
  36  *     constructor) will be used.
  37  * @constructor
  38  */
  39 base.Callstack = function(opt_error) {
  40   /** @type {Array<base.StackFrame>} */
  41   this.callstack = [];
  42
  43   this.getCallstackFromError_(opt_error || new Error());
  44
  45   // If no explicit Error was specified, remove this frame from the stack.
  46   if (!opt_error) {
  47     this.callstack.splice(0, 1);
  48   }
  49 };
  50
  51 /**
  52  * @return {string} The callstack as a newline-separated string.
  53  */
  54 base.Callstack.prototype.toString = function() {
  55   /**
  56    * @param {base.StackFrame} frame
  57    * @return {string}
  58    */
  59   var frameToString = function(frame) {
  60     var location = frame.file + ':' + frame.line + ':' + frame.column;
  61     if (frame.url) {
  62       location = frame.url + '/' + location;
  63     }
  64     if (frame.fn) {
  65       location = ' (' + location + ')';
  66     }
  67     return frame.fn + location;
  68   }
  69
  70   return this.callstack.map(frameToString).join('\n');
  71 };
  72
  73 /**
  74  * Parse the callstack of the specified Error.
  75  *
  76  * @param {Error} error
  77  * @private
  78  */
  79 base.Callstack.prototype.getCallstackFromError_ = function(error) {
  80   /**
  81    * @param {string} frame
  82    * @return {base.StackFrame}
  83    */
  84   var stringToFrame = function(frame) {
  85     var result = {};
  86     // Function name (optional) and location are separated by a space. If a
  87     // function name is present, location is enclosed in parentheses.
  88     var fnAndLocation = frame.split(' ');
  89     var location = fnAndLocation.pop().replace(/[()]/g, '');
  90     result.fn = fnAndLocation.shift() || '';
  91     // Location, line and column are separated by colons. Colons are also
  92     // used to separate the protocol and URL, so there may be more than two
  93     // colons in the location.
  94     var fullUrlAndLineAndCol = location.split(':');
  95     result.column = parseInt(fullUrlAndLineAndCol.pop(), 10);
  96     result.line = parseInt(fullUrlAndLineAndCol.pop(), 10);
  97     var fullUrl = fullUrlAndLineAndCol.join(':');
  98     // URL and file are separated by slashes. Slashes also separate the protocol
  99     // and URL.
 100     var urlAndFile = fullUrl.split('/');
 101     result.file = urlAndFile.pop();
 102     result.url = urlAndFile.join('/');
 103     return result;
 104   };
 105
 106   var callstack = error.stack
 107       .replace(/^\s+at\s+/gm, '') // Remove 'at' and indentation.
 108       .split('\n');
 109   callstack.splice(0, 1); // Remove 'Error'
 110   this.callstack = callstack.map(stringToFrame);
 111 }
 112
 113 })();