gecko/toolkit/devtools/DevToolsUtils.js

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JavaScript
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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
/* General utilities used throughout devtools. */
/**
* Turn the error |aError| into a string, without fail.
*/
this.safeErrorString = function safeErrorString(aError) {
try {
let errorString = aError.toString();
if (typeof errorString === "string") {
// Attempt to attach a stack to |errorString|. If it throws an error, or
// isn't a string, don't use it.
try {
if (aError.stack) {
let stack = aError.stack.toString();
if (typeof stack === "string") {
errorString += "\nStack: " + stack;
}
}
} catch (ee) { }
return errorString;
}
} catch (ee) { }
return "<failed trying to find error description>";
}
/**
* Report that |aWho| threw an exception, |aException|.
*/
this.reportException = function reportException(aWho, aException) {
let msg = aWho + " threw an exception: " + safeErrorString(aException);
dump(msg + "\n");
if (Components.utils.reportError) {
/*
* Note that the xpcshell test harness registers an observer for
* console messages, so when we're running tests, this will cause
* the test to quit.
*/
Components.utils.reportError(msg);
}
}
/**
* Given a handler function that may throw, return an infallible handler
* function that calls the fallible handler, and logs any exceptions it
* throws.
*
* @param aHandler function
* A handler function, which may throw.
* @param aName string
* A name for aHandler, for use in error messages. If omitted, we use
* aHandler.name.
*
* (SpiderMonkey does generate good names for anonymous functions, but we
* don't have a way to get at them from JavaScript at the moment.)
*/
this.makeInfallible = function makeInfallible(aHandler, aName) {
if (!aName)
aName = aHandler.name;
return function (/* arguments */) {
try {
return aHandler.apply(this, arguments);
} catch (ex) {
let who = "Handler function";
if (aName) {
who += " " + aName;
}
reportException(who, ex);
}
}
}