There is not much documentation and examples of drupal with behat test, so I will start with simplest. I will assume you have installed

I wrote about this great drupal find http://drupaldump.com/drush-cutie-about-minute-install-full-instance-dr…

but what was not obvious is how to reuse this drupal installation. Once you close terminal window, server closes and it doesn't work. There is a command 

I stumbled upon a great find, Drush Cutie. What it does is takes advantage of PHP's built-in web server (PHP >= 5.4) and uses a sqlite database to get a fresh, stand-alone copy of Drupal up and running, all in about a minute.

use Drupal\Core\Controller\ControllerBase;
use Drupal\my_module\SomeClass;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\HttpFoundation\Response;

class SomeController extends ControllerBase
{
    private $someProperty;

    public function __construct(SomeClass $someProperty)
    {

Getting into drupal 8 from drupal 7 is hard. Especially if you are new to OOP, some articles about what is what will help you on that way. I suggest the following in that order

Still new to this drupal 8 beast and trying to learn how to drill down data from entites. There are this magic getters and setters methods that get you data without need to write them. So

I had many vagrant machines and haven't really paid much attention to setting unique hostname, machine name and IP address, which resulted in mixed environments. Meaning I loaded one URL and I got files and database from the other vagrant machine. To debug what was really happening I went into devel/php and found out where is my mind I mean Index file :) to do that I echoed it like this.

UPDATE: This is changed now and author wants that we install drupal launcher and then drupal console per project as stated here so composer global require is no longer supported

https://docs.drupalconsole.com/en/getting/project.html

You may get this message trying to update drush globally via composer,
"To initialize a project, please create a composer.json file as described in the...."

so lets make it sure both are globally installed and required.

Download phar file with

curl -sS https://getcomposer.org/installer | php

then move it to /usr/local

To see where CLI settings are type

php --ini

It is possible that you will get this: