Extract source code & directories from the javascript .map files

extract_mapjs.php

<?php
/**
 * Created by PhpStorm.
 * User: edwinsturt
 * Date: 2020-06-24
 * Time: 00:45
 */

$file = 'main.ff0058ad.js.map';

if(file_exists($file)) {
    $json = json_decode(file_get_contents($file));

    $directories = [];

    foreach ($json->sources as $index => $source) {

        $dir = dirname($source);
        if (!is_dir($dir)) {
            mkdir($dir, 0755, true);
        }
        $data = explode('/', $source);
        $file = end($data);
        file_put_contents($dir . "/" . $file, $json->sourcesContent[$index]);
        $files[] = $dir . "/" . $file;

    }
    echo "<pre>All Source codes has been extracted from map file ";
    print_r($files);
}

Note that if the .map file is actually hostile, running this script may overwrite any files in your local operating system that you have write access to. The script assumes that $source is a safe local file path and it's safe to create and write directory hierarchy as whatever strings the .map file contains.

At very minimum, the variable $source should be sanity checked to not start with a slash and to not contain any sequences of ../ to avoid security vulnerability.