Blunder-JS
This is the JavaScript notifier for capturing errors in web browsers and reporting them to Blunder.
Installation
Using npm:
npm install blunder-js
Setup
Example configurations can be found in examples, including:
The notifier is built using umd and therefore can be imported with AMD, CommonJS2 or as property in root.
If you're using Node.js you might need to install the request library too, on which Blunder depends:
npm install request
Basic Usage
First you need to initialize the notifier with the project id and API key taken from Blunderify:
var blunder = projectId: 1 projectKey: 'abc' component: 'frontend';
Or if you are using browserify/webpack/etc:
var BlunderClient = ;var blunder = projectId: 1 projectKey: 'abc' component: 'frontend';
Then you can send a textual message to Blunder:
var promise = blunder;promise;promise;
Or report catched errors directly:
try // This will throw if the document has no head tag documenthead; catcherr blunder; throw err;
Alternatively, you can wrap any code which may throw errors using the client's wrap
method:
var { // This will throw if the document has no head tag. documenthead;}startApp = blunder; // Any exceptions thrown in startApp will be reported to Blunder.;
or use call
shortcut:
var { // This will throw if the document has no head tag. documenthead;} blunder;
Advanced Usage
Notice Annotations
It's possible to annotate error notices with all sorts of useful information at the time they're captured by supplying it in the object being reported.
try ; catch err blunder; throw err;
Severity
Severity allows categorizing how severe an error is. By default, it's set to error
. To redefine severity, simply overwrite context/severity
of a notice object. For example:
blunder;
User information
To send user information to Blunder, either create a filter or use setUser(userId: string, userEmail: string, userName: string)
on an instance of the BlunderClient
. You can also use setUserId(id: string)
, setUserEmail(email: string)
or setUserName(name: string)
on a client instance if you only have, or only care about one of the bits.
Since Blunder mostly works with .NET and their way of doing things, the backend will prefer grouping on UserName instead of the others. If you only set one piece of user info, make it UserName.
Filtering errors
There may be some errors thrown in your application that you're not interested in sending to Blunder, such as errors thrown by 3rd-party libraries, or by browser extensions run by your users.
The Blunder notifier makes it simple to ignore this chaff while still processing legitimate errors. Add filters to the notifier by providing filter functions to addFilter
.
addFilter
accepts the entire error notice to be sent to Blunder, and provides access to the context
, environment
, params
, and session
values submitted with the notice, as well as the single-element errors
array with its backtrace
element and associated backtrace lines.
The return value of the filter function determines whether or not the error notice will be submitted.
- If a null value is returned, the notice is ignored.
- Otherwise, the returned notice will be submitted.
An error notice must pass all provided filters to be submitted.
In the following example all errors triggered by admins will be ignored:
blunder;
Filters can be also used to modify notice payload, e.g. to set the environment and application version:
blunder;
Source map
In order to enable source map support you have to specify the path to the source map file according to the source map specification. For example, blunder.min.js has the following line:
//# sourceMappingURL=blunder.min.js.map
Please note that the Blunder backend downloads the source map file to process the backtrace. This means that the source map should be publicly accessible via HTTP. So, for example, don't expect source map support to work on your local webserver running on localhost
.
Custom source map URLs are supported by assigning a special property of notice.context
called sourceMaps
. The keys of the sourceMaps
object represent shell filename patterns and the values are URLs of your source maps.
blunder;
Custom reporters
If you're interested in inspecting the information reported to Blunder in your own code, you can register your own error reporter. Note that reporters added this way may be executed out-of-order.
In this example, reported errors are also logged to the console.
Unwrapping console
blunder-js automatically wraps console.log
function calls in order to collect logs and send them with first error. You can undo it using following code:
if env === 'development' let methods = 'debug' 'log' 'info' 'warn' 'error'; for let m of methods if m in console && consoleminner consolem = consoleminner;
Integration
window.onerror
blunder-js automatically setups window.onerror
handler when script is loaded. It also makes sure to call old error handler if there are any. Errors reported by window.onerror
can be ignored using ignoreWindowError
option:
var blunder = ignoreWindowError: true;
What does "Script error" mean?
See https://developer.mozilla.org/en/docs/Web/API/GlobalEventHandlers/onerror#Notes.
Contributing
Install dependencies:
npm install
Build project:
webpack
License
Copyright for portions of project are held by Airbrake Technologies, Inc, 2017 as part of project Airbrake. All other copyright for project Blunder are held by Per Christian B. Viken, 2017. It is free software, and may be redistributed under the terms specified in the LICENSE file.