Simple Application bootstrap file

<?php
/*
 * file: __bootstrap__.php
 * place this file in `document root` as __bootstrap__.php

 * As the first line in any script executed from the internet put:
 * include_once $_SERVER['DOCUMENT_ROOT'] .'/__bootstrap__.php';
 */

/* ---------------------------------------------------------------------------
 * 'APP_HOME_ROOT' is a defined constant that has the complete path to the
 *                 directory that holds the complete application
 *
 *  All the other directory paths used are defined from this.
 *
 *  It makes it very easy for me to move from windows to Linux.
 *
 *  Assume in root directory.
 *
 *  My version is run from a fixed directory under the 'application home directory'.
 *
 *  see: https://www.binpress.com/tutorial/php-bootstrapping-crash-course/146
 */


define('APP_HOME_ROOT', __DIR__ .'/'); // access all files based on this... simplifies moving to linux later

// Directory Constants so easy to move between o/s
define('APP_VENDOR_ROOT',     APP_HOME_ROOT .'vendor/');

// used by testing setup
// define('APP_BOOTSTRAP_ROOT',  APP_HOME_ROOT .'__bootstrap__/');

// this is always true
define('LIVE_HOME_ROOT',      APP_HOME_ROOT);

// this is always true
define('DEV_HOME_ROOT',       APP_HOME_ROOT);

// this is always true
define('DEVTEST_HOME_ROOT',   APP_HOME_ROOT .'tests/');

// true for now
define('SYSTEST_HOME_ROOT',   APP_HOME_ROOT .'tests/');