How to make array.forEach(asyncfn) synchronized?

Question

Say I have an array and I want to perform an async-function on each element of the array.

let a = [x1, x2, x3]

// I want to
await a.forEach(async (x) => {...         


        

Answer 1

Like this?

for (let x of a) {
  await fn(x);
}

Or if you really dislike creating a separate fn:

for (let x of a) {
  await (async v => {
    ...
  })(x);
}

You could even add it to Array.prototype:

Array.prototype.resolveSeries = async function(fn) {
  for (let x of this) {
    await fn(x);
  }
}

// Usage:
await a.resolveSeries(fn);

// Or:
await a.resolveSeries(async x => {
  ...
});