materio-base-d7/sites/all/modules/contrib/mail/reroute_email/tests/reroute_email_test.module

<?php

/**
 * @file
 * Provides Mail hook implementations for testing the Reroute Email module.
 */

/**
 * Implements hook_mail().
 *
 * This function allows testing Reroute Email's handling of a string passed for
 * message's body instead of an Array as required by drupal_mail. It also
 * allows testing the robustness of the handling of Cc and Bcc header keys.
 * Body, Cc and Bcc values are initialized from test case through $params.
 */
function reroute_email_test_mail($key, &$message, $params) {
  if ($key != 'test_reroute_email') {
    return;
  }
  $message['subject'] = "Reroute Email Test: Message body is a string, Cc and Bcc header keys have  a special case";

  // Body is provided as a string.
  if (!empty($params['body'])) {
    $message['body'] = $params['body'];
  }
  // Provide Cc and Bcc headers with an unexpected case.
  if (!empty($params['headers']['test_cc_key']) && !empty($params['headers'][$params['headers']['test_cc_key']])) {
    $message['headers'][$params['headers']['test_cc_key']] = $params['headers'][$params['headers']['test_cc_key']];
  }
  if (!empty($params['headers']['test_bcc_key']) && !empty($params['headers'][$params['headers']['test_bcc_key']])) {
    $message['headers'][$params['headers']['test_bcc_key']] = $params['headers'][$params['headers']['test_bcc_key']];
  }
}

/**
 * Implements hook_mail_alter().
 *
 * This helper function is necessary to catch message's body if it is a string
 * to make it an array to be compliant with drupal_mail and prevent a Warning:
 * implode(): Invalid arguments passed in DefaultMailSystem->format().
 */
function reroute_email_test_mail_alter(&$message) {
  // Only alter the email for the key test_reroute_email.
  if ($message['key'] != 'test_reroute_email') {
    return;
  }
  // Prevent Warning from drupal_mail because body is not an array.
  if (is_string($message['body'])) {
    // Record to be checked in test in the log entries.
    watchdog('reroute_email_test', 'A String was detected in the body: <pre>!body</pre>', array('!body' => $message['body']), WATCHDOG_NOTICE);
    // Convert body to an Array.
    $message['body'] = array($message['body']);
  }
}