signup_for_class.js

// google-chrome --headless --disable-gpu --remote-debugging-port=9222 <website>
// ssh -L localhost:1337:localhost:9222 <server>
// document.querySelector("#username").value = "<username>";

var attempts = 0;

function sleep(ms) {
    return new Promise(resolve => setTimeout(resolve, ms));
}

async function loggingSleep(ms) {
    while (ms > 0) {
        document.title = '[' + attempts + '] Sleeping for ' + (ms/1000) + 's...';
        await sleep(Math.min(ms, 5000));
        ms -= Math.min(ms, 5000);
    }
}

async function join_classes() {
    while (true) {
        try {
            document.getElementsByTagName("frame")[0].contentDocument.getElementsByTagName("frame")[0].contentDocument.getElementsByTagName("frame")[0].contentDocument.getElementsByTagName("frame")[2].contentDocument.querySelector("#DERIVED_REGFRM1_LINK_ADD_ENRL\\$82\\$").click();

            await loggingSleep(10 * 1000);

            document.getElementsByTagName("frame")[0].contentDocument.getElementsByTagName("frame")[0].contentDocument.getElementsByTagName("frame")[0].contentDocument.getElementsByTagName("frame")[2].contentDocument.querySelector("#DERIVED_REGFRM1_SSR_PB_SUBMIT").click();

            await loggingSleep(10 * 1000);

            document.getElementsByTagName("frame")[0].contentDocument.getElementsByTagName("frame")[0].contentDocument.getElementsByTagName("frame")[0].contentDocument.getElementsByTagName("frame")[2].contentDocument.querySelector("#DERIVED_REGFRM1_SSR_LINK_STARTOVER\\$214\\$").click();

            await loggingSleep(10 * 1000);

            attempts += 1;

            await loggingSleep(90 * 1000);
        }
        catch (err) {
            console.log("Caught error");
        }
    }
}

join_classes();