await-problem

const functions = [
    (callback) => {
        setTimeout (() => {
            console.log(4);
            callback && callback();
        }, 4000);
    },
    (callback) => {
        setTimeout (() => {
            console.log(2);
            callback && callback();
        }, 2000);
    }
]

const wait = async (arr, cb) => {
    // currently 'all done' is displayed before 2, 4
    await new Promise((resolve, reject) => {
        for (let func of arr) {
            func();
        }
        resolve();
    });
    cb();
}

const callback = () => {
    console.log('all done');
}

wait(functions, callback);