https://stackoverflow.com/questions/45316289/ember-action-passed-is-null-or-undefined-in-action-error

components.checkout-form.js

import Ember from 'ember';

export default Ember.Component.extend({
   actions:{
    selectDate(){
      console.log(' selectDate in checkout-form component');
    }
  }
});

components.course-date.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',
  actions:{
    selectDateInController(){
      console.log(' selectDate in controller');
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
Hi{{log 'first' this}}
<br>
{{#checkout-form as |selectDate| }}
 {{!-- 
 here context is controller not the checkout-form component
 Whatever you want to access from component, then component should yield those values.
 --}}
 {{course-date selectDate=(action 'selectDateInController')}}
 {{course-date selectDate=selectDate}}
{{/checkout-form}}
<br>
{{outlet}}
<br>
<br>

templates.components.checkout-form.hbs

{{yield (action 'selectDate')}}

templates.components.course-date.hbs

<button {{action selectDate}}> CourseDate </button>
{{yield}}

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1"
  }
}