Email obfuscator

codegolf-01082021.php

<?php

$email = "[email protected]";
$expectedResult = "ma*****@co***********.com";
$result = obfuscator($email);

if ($result == $expectedResult) {
    echo "You're great and smart".PHP_EOL;
    exit(0);
} else {
    echo "You done goofed".PHP_EOL;
    exit(1);
}

/**
 * Obfuscates email addresses
 * [email protected] == ry**@ye**********.com
 *
 * @param string $email
 *
 * @return string
 */
function obfuscator(string $email)
{
    $out = [];
    foreach (explode("@", $email) as $str) {
        array_push(
            $out,
            preg_replace_callback(
                '/(?<=^.{2})[^.]*/',
                function ($m) {
                    return str_repeat('*', strlen($m[0]));
                },
                $str
            )
        );
    }

    return implode('@', $out);
}