StackOverflow Answer: 37618621

components.my-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  classNames: ['cursor-pointer'],

  clickListener: Ember.on('click', function(){
    let doSth = this.get('doSth');
    
    if (doSth) {
      console.log('Click listener is about to trigger action');
      doSth();
    }
  })
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  actions: {
    doSth: function() {
      console.log('doSth action is being handled');
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{my-component doSth=(action 'doSth')}}
<br>
<br>

templates.components.my-component.hbs

{{yield}}

tests.helpers.resolver.js

import Resolver from '../../resolver';
import config from '../../config/environment';

const resolver = Resolver.create();

resolver.namespace = {
  modulePrefix: config.modulePrefix,
  podModulePrefix: config.podModulePrefix
};

export default resolver;

tests.integration.components.my-component-test.js

import { moduleForComponent, test } from 'ember-qunit';
import hbs from 'htmlbars-inline-precompile';

moduleForComponent('my-component', 'Testing doSth', {
  integration: true
});

test('should call doSth() on click', function(assert) {
  this.set('doSth', () => assert.ok(true));
  this.render(hbs`{{my-component doSth=(action doSth)}}`);
  this.$('.cursor-pointer').click(); // triggers doSth() correctly
});

tests.test-helper.js

import resolver from './helpers/resolver';
import {
  setResolver
} from 'ember-qunit';

setResolver(resolver);

twiddle.json

{
  "version": "0.8.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": true
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.5.1",
    "ember-data": "2.5.2",
    "ember-template-compiler": "2.5.1"
  }
}