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

const page = new Object();
page.listeners = [];

page.on = async function (callback) {
    page.listeners.push(callback);
}

page.fire = async function () {
    page.listeners.forEach(async element => {
        await element("msg");
    });
}

async function eval(callback) {
    return await callback();
}

work = async () => {
    await page.on(async (msg) => {
        if (msg === "msg") {
            const val = await eval(function () {
                throw new Error("wrong");
            });
        }
    });
    await sleep(2000);
    await page.fire();
}

(async function () {
    try {
        await work();
    } catch (e) {
        console.log(e);
    }
})();