SOURCE

PromiseAll = function(promise){
    return new Promise((resolve,reject)=>{
        let res = []
    let len = promise.length
    let con = 0
    for(let i=0;i<len;i++){
        Promise.resolve(promise[i]).then(data=>{
            res[i] = data
            if (i + 1 == len){
                resolve(res)
            }
        }).catch(err=>{
            throw(err)
        })
    }
    })

}

const promise1 = Promise.resolve(3);
const promise2 = 42;
const promise3 = new Promise((resolve, reject) => {
  setTimeout(resolve, 100, 'foo');
});

PromiseAll([promise1, promise2, promise3]).then((values) => {
  console.log(values);
});