Drupal git branch different database

settings.local.php

<?php
$databases = array (
  'default' => 
  array (
    'default' => 
    array (
      'driver' => 'mysql',
      'username' => 'root',
      'password' => 'root',
      'port' => '',
      'host' => 'localhost',
      'database' => 'regular_database',
      'prefix' => '',
    ),
  ),
);

/** 
* CHANGE CONFIGURATION BASED ON GIT
* */

$databases_by_branch = array(
  'branch_name_1' => array (
      'driver' => 'mysql',
      'username' => 'root',
      'password' => 'root',
      'port' => '',
      'host' => 'localhost',
      'database' => 'branch_name_1_database',
      'prefix' => '',
    ),
  'branch_name_2' => array (
      'driver' => 'mysql',
      'username' => 'root',
      'password' => 'root',
      'port' => '',
      'host' => 'localhost',
      'database' => 'branch_name_2_database',
      'prefix' => '',
    )
);
$branchname_from_HEAD = file(DRUPAL_ROOT . '/.git/HEAD');
$branchname_from_HEAD = $branchname_from_HEAD[0]; //get the string from the array
$a_branchname = explode("/", $branchname_from_HEAD); //seperate out by the "/" in the string
 
$branchname = preg_replace('/\s/', '', $a_branchname[count($a_branchname) - 1]);

if(isset($databases_by_branch[$branchname])) {
  $databases['default']['default'] = $databases_by_branch[$branchname];
}