sbt plugin for running JavaScript tests on the JVM with browser APIs


sbt plugin for running JavaScript tests on the JVM with browser APIs


Why another JavaScript test plugin? sbt-js-test was built to provide

  1. A JavaScript test environment with the browser API available
  2. Supporting multiple browser APIs
  3. While only requiring the JVM
  4. And being JavaScript test framework agnostic (Only Jasmine 2.x is supported at the moment, though.)


sbt-js-test is an auto plugin. Simply add the following lines to an sbt file in your project's project directory, such as project/plugins.sbt:

libraryDependencies += "org.webjars.bower" % "jasmine" % "2.4.1" % "runtime"
addSbtPlugin("com.joescii" % "sbt-js-test" % "0.2.0")


After installation, execute the jsLs task to list the JavaScript assets that will be used for running tests. The first list are files found in the jsResource setting and will be loaded for every test. The second list are files found in the jsTestResource setting and will all be executed by jsTest or individually by jsTestOnly. Note that jsLs lists the files in the exact order they will be loaded. If you don't see your javascript files or they are not in the correct order to run, see Custom Configuration below.

Run all of your tests with jsTest. Selectively run individual test files from jsTestResources with jsTestOnly.

Custom Configuration

By default, we look in src/main/js, src/main/javascript, and src/main/resources for *.js files in jsResource. Similarly for jsTestResource, we look in src/test/js, src/test/javascript, and src/test/resources. The files are loaded in alphabetical order thanks to your OS's implementation of You can control the files as you would with any other sbt setting of type Seq[File].

jsResources := {
  val main = (sourceDirectory in Compile).value
  val test = (sourceDirectory in Test).value
    main / "js" / "angular" / "angular.js",       // Make sure angular loads before the mocks
    main / "js" / "angular" / "angular-mocks.js",
    main / "js" / "sample-app.js",
    test / "js" / "mocks"                         // Have mocks always available for jsTestOnly 

jsTestResources := {
  val test = (sourceDirectory in Test).value
  ((test / "scripts") ** "*.spec.js").get         // Using sbt's handy PathFinder

By default, the browser API provided mimics Chrome. You can configure any of Chrome, Firefox, and IE11 for your testing. All of your tests will be run for each browser.

import JsTestBrowsers._
jsTestBrowsers := Seq(Chrome, Firefox38, InternetExplorer11)

By default, test output will print to your console in color. If this makes a mess in your console or in your continuous integration server logs, you can turn it off.

jsTestColor := false

Asynchronously-loaded Assets

When testing applications with some sort of asynchronous module definition (like requireJs), it is necessary for sbt-js-test to wait until all your assets are loaded. To enable this feature you should turn on the jsAsyncWait setting.

jsAsyncWait := true

This will cause sbt-js-test to wait indefinitely before running your test specs. The best approach is to notify the plugin when your assets have loaded by setting window.sbtJsTest.readyForTestsToRun to true in your javascript. For example, you can configure requireJs to notify sbt-js-test as shown below.

  deps: [
  callback: function(){
    window.sbtJsTest.readyForTestsToRun = true;

Alternatively, you can specify jsAsyncWaitTimeout in milliseconds if you are unable to signal the plugin via window.sbtJsTest.readyForTestsToRun.

jsAsyncWaitTimeout := Some(2500)

See test-projects/requireJs and test-projects/requireJsTimeout for a full-working example of both approaches.


As with any open source project, contributions are greatly appreciated. If you find an issue or have a feature idea, we'd love to know about it! Any of the following will help this effort tremendously.

  1. Issue a Pull Request with the fix/enhancement and tests to validate the changes. OR
  2. Issue a Pull Request with failing tests to show what needs to be changed OR
  3. At a minimum, open an issue to let us know about what you've discovered.

Pull Requests

Below is the recommended procedure for git:

  1. Fork it
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push the branch (git push origin my-new-feature)
  5. Create new Pull Request

Please include as much as you are able, such as tests, documentation, updates to this README, etc.


Part of contributing your changes will involve testing. You can execute them via the it:test sbt task in this project. The test-projects sub-directory contains an independent sbt multi-project that the tests run against. At a minimum, we ask that you run the tests with your changes to ensure nothing gets inadvertently broken. If possible, include tests which validate your fix/enhancement in any Pull Requests.

Change Log

  • 0.2.0: Added support for asynchronously-loaded javascript assets.
  • 0.1.0: Initial release.


sbt-js-test is licensed under APL 2.0.

Copyright 2016 Joe Barnes

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.