Accessing this.$() in qunit test

I’ve created a small mixin that helps a component to be hidden when the user clicks outside of the component. I’d now like to add a test for it, where I trigger a click event outside a component that extends the mixin.

All I want to test is that a method called onOutsideClick is called. For this, I’m trying to draw inspiration from: https://github.com/nucleartide/ember-outside-click

But when I do this:

const HideOnOutsideClickObject = Ember.Component.extend(HideOnOutsideClick, {
})

test('click outside', function(assert) {
  const element = this.$()[0]

  const event = document.createEvent('MoseEvents')
  event.initEvent(event, true, true)
  element.dispatchEvent(event)

  assert.ok(HideOnOutsideClickObject.onOutsideClick)
})

I get an error saying that this.$() is not a function. What am I missing?

I’ve of course imported the mixin as I should.