Lookout Hackers Blog

Over the past few months, members of our front-end team have been busy revamping much of our web application. While I can’t tell you about the specifics of what is coming down the pike, I can tell you about some of the technologies that we’re using along the way, most notably: Jasmine.

For the unfamiliar, Jasmine is a JavaScript-based unit testing library which can help make test-driving full applications in JavaScript feasible.

With some of the recent changes that I still can’t tell you about (sorry), Jasmine has become an important part of our application development stack. We now have a need to run our Jasmine unit tests as part of our “standard” continuous integration workflow and release process. This means we must run Jasmine tests when we run our normal unit tests, Rails functional tests and Selenium tests.

Since we’re already big users of the Selenium testing service provided by Sauce Labs, it made sense to build on top of their infrastructure to run our Jasmine tests.

Using the Sauce gem and the Jasmine gem from Pivotal Labs, we can effortlessly use either a local browser or a remote browser hosted by Sauce. The “trick” is some of the Rake tasks provided by the two gems:

-> % rake -T jasmine
rake jasmine                 # Run specs via server
rake jasmine:ci              # Run continuous integration tests
rake jasmine:sauce           # Execute Jasmine tests in a Chrome browser on Sauce Labs
rake jasmine:sauce:all       # Execute Jasmine tests in Chrome, Firefox and Internet Explorer on Sauce Labs
rake jasmine:sauce:chrome    # Execute Jasmine tests in chrome
rake jasmine:sauce:firefox   # Execute Jasmine tests in firefox
rake jasmine:sauce:iexplore  # Execute Jasmine tests in iexplore

The first two tasks (jasmine and jasmine:ci) are provided by the Jasmine gem, while the rest are provided by the Sauce gem (after requiring sauce/jasmine/rake in our Rakefile).

The only pre-requisite to running the jasmine:sauce tasks is that you need a Sauce Connect tunnel open, to do this you only need to open a separate terminal to run: sauce connect.

Once the tunnel is up and running, invoking rake jasmine:sauce will automatically spin up a Jasmine test server, a Sauce Labs VM with Chrome, and run your tests!

-> % rake jasmine:sauce
Waiting for jasmine server on 3001...
jasmine server started.
Starting job named: Jasmine Test Run 1341870335
Waiting for suite to finish in browser ...
..........................

Finished in 19.95 seconds
26 examples, 0 failures
-> %

Jasmine on Jenkins

Running tests locally is fine, but nothing compares to running those tests in Jenkins. At Lookout, we use both Gerrit and Jenkins heavily throughout our development process, so being able to kick-off Jasmine tests from Jenkins is very important.

To accomplish this we have a dedicated slave for running nothing but Jasmine tests. The reason for dedicating a slave is so that we can keep a Sauce Connect tunnel open across multiple test runs in order to keep tests as fast as possible.

We use the sauce-connect puppet module to run the tunnel, and then bind all our jobs to the “jasmine” label to make them only run on that slave. One thing we found is that the Sauce Connect tunnel can get a bit “wonky” if it’s not regularly restarted, so we had to make sure the tunnel is torn down every night.

Our node (in Puppet) for the builder looks something like this:

node /^jasmine-builder$/ inherits server {
  class {
    'sauceconnect' :
      username => 'REDACTED',
      apikey   => 'EVENMOREREDACTED';
  }

  cron {
    'restart-sauceconnect' :
      ensure  => present,
      command => 'service sauce-connect restart',
      user    => 'root',
      minute  => 0,
      hour    => 3,
      require => Class['sauceconnect'];
  }
}

By splitting off our Jasmine tasks to run on this dedicated Jasmine builder, it only takes about 2 minutes to run all the tests.

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With a little bit of elbow grease we brought together a lot of the existing tools we had in our developer toolchest and now we’re able to provide first-class support for building, testing and deploying JavaScript applications.

Not bad for a “mobile company” if you ask me!

- R. Tyler Croy