Scroll up to a given timestamp.

twitter-gc-autoscroll.js

const messageList = document.querySelector("main > div > div > div > div:nth-child(2) > div > div > div > div > div");

/**
 * Scroll to the top of the message list.
 **/
const scrollToTop = async () => {
    messageList.scrollTop = 0;
    
    return await new Promise((resolve) => setTimeout(resolve, 1000));
};

/**
 * Get a Date object from a relative timestamp (e.g. "8:12 PM") or 
 * full date string.
 **/
const getDate = (dateString) => {
    /**
     * If no date prefix, add one.
     **/
    if (Number(dateString[0])) {
        dateString = `${new Date().toDateString()}, ${dateString}`;
    } else if (dateString.startsWith("Yesterday")) {
        const yesterday = new Date(new Date().setDate(new Date().getDate() - 1));
        dateString = dateString.replace("Yesterday", yesterday.toDateString());
    }

    return new Date(dateString);
}


/**
 * Get the earliest timestamp from the loaded messages.
 **/
const getEarliestTimestamp = async () => {
    const timestamp = messageList.querySelector("div[data-testid='cellInnerDiv'] > div > div:nth-child(2) div[dir='auto'] span:nth-child(3)").textContent;
    const earliestTimestamp = getDate(timestamp);

    console.log({ earliestTimestamp });
    return await new Promise(
        (resolve) => setTimeout(() => resolve(earliestTimestamp))
    );
};

/**
 * Scroll until the earliest timestamp is <= the given date.
 **/
const scrollUntilTimestamp = async (dateString) => {
    const scrollUntil = getDate(dateString);
    console.log(`Scrolling until ${scrollUntil}`);

    while (await getEarliestTimestamp() > scrollUntil) {
        await scrollToTop();
    }
};