Recently I had the pleasure of setting up Angular tests within a project. For testing, we decided on Karma test runner by Angular team. You can find details about the reasoning at the end of the post, but basically the idea was that we’d like to stick with the runner built and used by the Angular team itself.
The project is currently a Rails gem and there are a bunch of nice tutorials on how integrate the two (see resources), but this project has aspirations to become a full-blown Angular app without any direct Rails dependencies. So, solutions like rails_karma gem or rails assets was not an option.
The good news is that the project in question used Browserify and sprockets-browserify gem to integrate it into Rails. After a bit of investigation, we came upon karma-browserify node module. This way, the resources under test were still served by browserify in the same manner as they would be served with the live application, but Rails was actually not needed to run the tests. The module in question essentially adds Karma preprocessors that make Karma aware of browserify served resources. In the end, this made our tests run fast, without involving Rails, which is a nice bonus.
The coffeescript configuration that ended up running the test suite:
Just run karma with
karma start spec/karma.config.coffee and that’s it.