How can I set up mocha tests to run Ember initializers so injected objects are defined?

My Ember app injects an "i18n" object into the container via an initializer, which is later looked up with "this.container.lookup('i18n:main')" in a controller 'preferredLanguage' computed property.

A mocha unit test which tests the controller 'preferredLanguage' property, fails due to "i18n is not defined". How can I set up the mocha tests to run Ember application initializers so injected objects are defined when looked up from the container during unit testing?