select is not broken, or is it?

components.my-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  targetAction: 'mostAwesomeAction',
  doSomething() {
    this.sendAction('targetAction', 'this value is the greatest value');
  }
});

components.outer-component.js

import Ember from 'ember';

export default Ember.Component.extend({
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  myService: Ember.inject.service(),
});

mixins.my-mixin.js

import Ember from 'ember';

export default Ember.Mixin.create({
  myService: Ember.inject.service(),
  count: 0,
  actions: {
    mostAwesomeAction(value) {
      this.incrementProperty('count');
      this.get('myService').set('awesomeValue', value + this.get('count'));
    }
  }
})

routes.application.js

import Ember from 'ember';
import MyMixin from '../mixins/my-mixin';

const DummyMixin = Ember.Mixin.create({});

export default Ember.Route.extend(DummyMixin, MyMixin, {
  actions: {
  }
});

services.my-service.js

import Ember from 'ember';

export default Ember.Service.extend({
  awesomeValue: 'nothing yet',
});

templates.application.hbs

<p>This value should be updated by action defined in mixins/my-mixin when you click on the button:</p>

<p>Value from service: {{myService.awesomeValue}}</p>

<h2>No Nesting</h2>
<p>This component is not nested in another component and therefore propagates action up:
{{my-component text='this button should update value'}}</p>

<h2>Nesting</h2>
<p>This button is wrapped in an extra component so it does <strong><em>NOT</em></strong> bubble the route action: {{outer-component text='this button should NOT work'}}</p>

templates.components.my-component.hbs

<button {{action (action doSomething)}}>Click on Me: {{text}}</button>

templates.components.outer-component.hbs

{{my-component text=text}}

tests.helpers.destroy-app.js

import Ember from 'ember';

export default function destroyApp(application) {
  Ember.run(application, 'destroy');
}

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.helpers.start-app.js

import Ember from 'ember';
import Application from '../../app';
import config from '../../config/environment';

const { run } = Ember;
const assign = Ember.assign || Ember.merge;

export default function startApp(attrs) {
  let application;

  let attributes = assign({rootElement: "#test-root"}, config.APP);
  attributes = assign(attributes, attrs); // use defaults, but you can override;

  run(() => {
    application = Application.create(attributes);
    application.setupForTesting();
    application.injectTestHelpers();
  });

  return application;
}

tests.test-helper.js

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

setResolver(resolver);

twiddle.json

{
  "version": "0.11.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "release",
    "ember-data": "2.11.0",
    "ember-template-compiler": "release",
    "ember-testing": "release"
  },
  "addons": {}
}