ForEach method

aForEach.ts

// Signature of the callback
type CallBackForEach<T> = (
  value: T,
  index?: number,
  collection?: T[]
) => Promise<void>;

/**
 * Async ForEach function
 *
 * @export
 * @template T
 * @param {T[]} elements
 * @param {CallBackForEach<T>} cb
 * @returns {Promise<void>}
 */
async function aForEach<T>( elements: T[], cb: CallBackForEach<T> ): Promise<void> {
  for (const [index, element] of elements.entries()) {
    await cb(element, index, elements);
  }
}

// You can use as follows
const array = [1, 2, 3, 4];

const output: number[] = [];

await aForEach<number>(array, async (i) => {
  output.push(i);
});