Testing Support

Lein-cljsbuild has built-in support for running external ClojureScript test processes. Test commands are configured via the :test-commands map. Each key in this map names a test command, and each value is a vector representing a shell command to run for that test:

(defproject lein-cljsbuild-example "1.2.3"
  :plugins [[lein-cljsbuild "1.1.7"]]
  :cljsbuild {
    :test-commands
      {"my-test" ["phantomjs" "phantom/unit-test.js" "..."]})

This example creates one test named "my-test", that will run phantomjs with a couple of arguments. The following command will run this test:

$ lein cljsbuild test my-test

Alternately, this command will run all configured tests:

$ lein cljsbuild test

If hooks are enabled, this will also result in the tests being run:

$ lein test

Testing with PhantomJS

For ClojureScript code that targets web browsers (as opposed to Node.js), it is often useful to run unit tests in the context of a web browser. This allows code that has side-effects (e.g. DOM manipulation) to be tested.

PhantomJS is a headless Webkit-based browser with full JavaScript support. This means that it can do most anything you would expect a desktop browser to do, except it does not have a GUI. PhantomJS can be automated via JavaScript, and thus is convenient to use for running automated tests.

The advanced example project contains an example of how to use PhantomJS for running ClojureScript tests. There are several components that come together to make this work:

1. A :builds entry dedicated to the test code in the test-cljs directory. This compiles the unit tests into JavaScript (so that it they can be run by PhantomJS).

2. A static HTML page with a <script> tag that will pull in the compiled unit test code when the page is loaded.

3. A :test-commands entry that runs PhantomJS, passing it a simple script. This script directs PhantomJS to load the static HTML page, and once it's loaded, to call the ClojureScript unit test entry point.