michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: module.metadata = {
michael@0:   "stability": "experimental"
michael@0: };
michael@0: 
michael@0: const { Cc, Ci, components } = require("chrome");
michael@0: const { parseStack, sourceURI } = require("toolkit/loader");
michael@0: const { readURISync } = require("../net/url");
michael@0: 
michael@0: exports.sourceURI = sourceURI
michael@0: 
michael@0: function safeGetFileLine(path, line) {
michael@0:   try {
michael@0:     var scheme = require("../url").URL(path).scheme;
michael@0:     // TODO: There should be an easier, more accurate way to figure out
michael@0:     // what's the case here.
michael@0:     if (!(scheme == "http" || scheme == "https"))
michael@0:       return readURISync(path).split("\n")[line - 1];
michael@0:   } catch (e) {}
michael@0:   return null;
michael@0: }
michael@0: 
michael@0: function nsIStackFramesToJSON(frame) {
michael@0:   var stack = [];
michael@0: 
michael@0:   while (frame) {
michael@0:     if (frame.filename) {
michael@0:       stack.unshift({
michael@0:         fileName: sourceURI(frame.filename),
michael@0:         lineNumber: frame.lineNumber,
michael@0:         name: frame.name
michael@0:       });
michael@0:     }
michael@0:     frame = frame.caller;
michael@0:   }
michael@0: 
michael@0:   return stack;
michael@0: };
michael@0: 
michael@0: var fromException = exports.fromException = function fromException(e) {
michael@0:   if (e instanceof Ci.nsIException)
michael@0:     return nsIStackFramesToJSON(e.location);
michael@0:   if (e.stack && e.stack.length)
michael@0:     return parseStack(e.stack);
michael@0:   if (e.fileName && typeof(e.lineNumber == "number"))
michael@0:     return [{fileName: sourceURI(e.fileName),
michael@0:              lineNumber: e.lineNumber,
michael@0:              name: null}];
michael@0:   return [];
michael@0: };
michael@0: 
michael@0: var get = exports.get = function get() {
michael@0:   return nsIStackFramesToJSON(components.stack.caller);
michael@0: };
michael@0: 
michael@0: var format = exports.format = function format(tbOrException) {
michael@0:   if (tbOrException === undefined) {
michael@0:     tbOrException = get();
michael@0:     tbOrException.pop();
michael@0:   }
michael@0: 
michael@0:   var tb;
michael@0:   if (typeof(tbOrException) == "object" &&
michael@0:       tbOrException.constructor.name == "Array")
michael@0:     tb = tbOrException;
michael@0:   else
michael@0:     tb = fromException(tbOrException);
michael@0: 
michael@0:   var lines = ["Traceback (most recent call last):"];
michael@0: 
michael@0:   tb.forEach(
michael@0:     function(frame) {
michael@0:       if (!(frame.fileName || frame.lineNumber || frame.name))
michael@0:       	return;
michael@0: 
michael@0:       lines.push('  File "' + frame.fileName + '", line ' +
michael@0:                  frame.lineNumber + ', in ' + frame.name);
michael@0:       var sourceLine = safeGetFileLine(frame.fileName, frame.lineNumber);
michael@0:       if (sourceLine)
michael@0:         lines.push('    ' + sourceLine.trim());
michael@0:     });
michael@0: 
michael@0:   return lines.join("\n");
michael@0: };