How to test component methods?

Testing
1

I have component with one method and service, which can run functions for some components.

export default Ember.Component.extend({
  foo: false,

  bar() {
    this.set('foo', true);
  },

  someService: Ember.inject.service('some-service'),

  didInsertElement: function () {
    const someService = this.get('someService');
    someService.registerComponent(this);
  },
});

export default Ember.Service.extend({
  components: [],
  registerComponent: function (component) {
    let components = this.get('components');
    components.push(component);
  },
  runBar(index) {
    let components = this.get('components');
    components[index].bar();
  }
});
  1. How can I write tests for bar() method?
  2. And also how can I write tests for this service?
  3. Or how can I refactor this approach?