Debugging and Testing with Symfony's Mailer Component

When SwiftMailer was the standard component for sending E. mail in Symfony, we could use "enqueue" as a simple means of saving E. mails to a text file that could be easily be tested and debugged.

Often, during testing and debugging, we don't want to bother with actually sending the E. mail and all that malarkey with transports and protocols.

With the new Symfony Mailer Component this isn't so easy to do.

But we can, edit our .env.local, .env.dev, or .env file to include:

MAILER_URL=null://null

And then edit vendor/symfony/mailer/Transport/NullTransport.php and paste the following code into the doSend method:

protected function doSend(SentMessage $message): void {
    $now = new \DateTime();
    $envelope = $message->getEnvelope();
    file_put_contents(
        dirname(__DIR__) .
            '../../../../var/mail/' .
            $now->format('Y-m-d-H-i-s'),
        json_encode([
            'sender' => $envelope->getSender()->toString(),
            'recipients' => array_map(function ($recipient) {
                return $recipient->toString();
            }, $envelope->getRecipients()),
            'messageId' => $message->getMessageId(),
            'debug' => $message->getDebug(),
            'message' => $message->getMessage()->toString()
        ])
    );
}

This is just a quick hack-up. The handling of ./var/mail/ is hardly what could be called "robust". But it's fine for testing and debugging environments.