Chatting to an SMTP server with ReactPHP

gistfile1.php

<?php

require "vendor/autoload.php";

use React\Promise\Deferred;

$loop = React\EventLoop\Factory::create();
$stream = @ stream_socket_client('tcp://gmail-smtp-in.l.google.com:25', $errNo, $errStr, 10);
$connection = new React\Socket\Connection($stream, $loop);

$deferred = new React\Promise\Deferred();

$connection->on('data',
    function ($data) {
        echo "<<< $data\n";
    }
);

$connection->once('data',
    function ($data, $conn) use ($deferred) {
        $deferred->resolve(array($data, $conn));
    }
);

$deferred->promise()
    ->then(function ($data) use ($connection) {
            $deferred = new Deferred();

            $connection->write("HELO flowsa.com\r\n");
            $connection->once('data',
                function ($data) use ($deferred) {
                    $deferred->resolve($data);
                }
            );

            return $deferred->promise();
        }
    )
    ->then(function ($data) use ($connection) {
            $deferred = new Deferred();

            $connection->write("MAIL FROM: <stephen@flowsa.com>\r\n");
            $connection->once('data',
                function ($data) use ($deferred) {
                    $deferred->resolve($data);
                }
            );

            return $deferred->promise();
        }
    )
    ->then(function ($data) use ($connection) {
            $deferred = new Deferred();

            $connection->write("RCPT TO: <stephenfrankza@gmail.com>\r\n");
            $connection->once('data',
                function ($data) use ($deferred) {
                    $deferred->resolve($data);
                }
            );

            return $deferred->promise();
        }
    )->then(function ($data) use ($connection) {
            $deferred = new Deferred();

            $connection->write("RCPT TO: <this-email-does-not-exist-asdf123@gmail.com>\r\n");
            $connection->once('data',
                function ($data) use ($deferred) {
                    $deferred->resolve($data);
                }
            );

            return $deferred->promise();
        }
    );

$loop->run();

This was great, used it to write tests for an SMTP server all inside the same loop.

https://bitbucket.org/david_garcia_garcia/smtpserver/src/a4b5f786363a284908b8c3ab478d17f66820b523/tests/ServerTest.php?at=1.0.x&fileviewer=file-view-default#ServerTest.php-100