Getting started

This guide walks you through installation and very basic setup of tests in a project. If you’re only interested in simple browser tests embedded in a web page, see the browser testing page.


Buster.JS on the command-line requires Node.js 0.6.3 or newer and npm. Node.js 0.6.3 and newer comes with npm bundled on most platforms.


  1. Get the latest Node installer from You need Node 0.6.3 or newer.
  2. npm install -g buster


Installing npm packages with sudo causes multiple problems, and is not recommended. If you cannot use npm without sudo after using the installer, try changing ownership of the node installation to your user.


  1. Install Node 0.6.3 or later with your favorite package manager. If you don’t have one, follow these simple build instructions.
  2. npm install -g buster


  1. Get the latest Node installer from You need Node 0.6.3 or newer.
  2. npm install -g buster

Create config file

Add a config file to your project. Call it test/buster.js or spec/buster.js. This way you don’t have to tell Buster.JS about it with --config every time you run tests. ./buster.js will also be recognized.

var config = module.exports;

config["My tests"] = {
    rootPath: "../",
    environment: "browser", // or "node"
    sources: [
    tests: [

// Add more configuration groups as needed

For browser tests, list all your source files in sources and test files in tests. For Node.js tests, you don’t need to specify sources as you typically require your source files directly in the test files.

Read the full configuration documentation for details.

Note that you may not “dot out” in sources, tests, etc. Paths are resolved relative to the directory where the configuration file lives. If your sources live outside this directory, adjust the root directory using the rootPath property (which is also resolved against the config file location, unless absolute).

Write tests

Given the config file above, all files named <something>-test.js in the same folder as the config file itself will be loaded. You can of course change the glob pattern to better suit your needs. **/*-test.js would for example recursively load all <something>-test.js in the same folder the config file is in, and all its sub folders.

A test case looks like this:

// Browser tests

buster.testCase("A module", {
    "states the obvious": function () {

The BDD inclined might prefer this alternate syntax:

buster.spec.expose(); // Make some functions global

describe("A module", function () {
    it("states the obvious", function () {

If your test is a Node.js test, you also need to require Buster.JS:

// Node.js tests
var buster = require("buster");
var myLib = require("../lib/my-lib");

buster.testCase("A module", {
    "states the obvious": function () {

See the full Test case docs and referee docs for details. There are also mocks and stubs and more, via the buster-sinon module.

Run tests

Node.js tests

For testing on Node.js we recommend to install Buster.JS locally. If you have installed it globally (-g flag in npm install -g buster) you have to ensure it can be found by Node.js. One option is to set NODE_PATH to the global installed modules, which is done during the installation of Node.js on linux automatically, but unfortunately not on windows. Another option is to create a link to Buster.JS with the command npm link buster executed in the root of the project.

Node.js tests can be run by simply typing node test/some-test.js. Doing this requires nothing more than a file with tests (i.e. you don’t need the above configuration).

While node test/my-test.js is nice and convenient, you want to use the buster-test binary to get at the full power of Buster.JS. Open a terminal, cd to your project, and type in buster-test. Here’s the output from the test run of posix-argv-parser:


See the Node.js testing documentation for more.

Browser tests

First, start a server. Open a terminal and type in buster-server.


Capture some browsers to run the tests in by visiting the URL. Click the grey capture button to actually perform the capture.


Then you’re ready to run the tests with buster-test.


See the browser testing documentation for more.

Hybrid tests

If your project has both Node.js and browser tests, and your config file specifies multiple groups for the different environments, running buster test will automatically run all the groups, both Node.js and browser. This requires that you already have a buster-server up and running.

If you only want to run tests for one environment, use buster test --environment browser or buster test -e node.

You have to manually make sure your test cases and source files are able to run in both browsers and Node.js. Here’s an example:

if (typeof require != "undefined") {
    var buster = require("buster");
    var myLib = require("../lib/my-lib");

buster.testCase("A test case", {
    "test it": function () {

See the hybrid testing documentation for more.