Overrides a user's password in MemberPress signup (guests only) and emails them a new one instead

mepr-ignore-and-override-password.php

<?php
function mepr_ignore_password_error($errors) {
  if(!MeprUtils::is_user_logged_in() && !empty($errors)) {
    foreach($errors as $i => $e) {
      if(preg_match("#P?p?assword#", $e)) { //If this is an error about the password let's unset it -- we'll set the password later
        $_POST['mepr_ignoring_password'] = true; //Artificially setting a POST var to ensure we only reset the proper passwords
        unset($errors[$i]);
      }
    }
  }
  
  return $errors;
}
add_filter('mepr-validate-signup', 'mepr_ignore_password_error');

function mepr_override_password($product_price, $user, $mepr_product_id, $transaction_id) {
  if(!isset($_POST['mepr_ignoring_password']) || $_POST['mepr_ignoring_password'] === false)
    return;
  
  $random_password = uniqid();
  wp_set_password($random_password, $user->ID);
  
  wp_mail($user->user_email, 'Your password for SOME SITE', "Your password for SOME SITE is: {$random_password}<br/>You can <a href=\"http://somesite.com/login/\">login here</a>.", array('Content-Type: text/html'));
}
add_action('mepr-process-signup', 'mepr_override_password', 10, 4);