Example of how to "recursively" call an async function, using the event loop (setTimeout). (NodeJS)

recurseByEventLoopTimer.js

function delay(ms) {
  return new Promise(res => setTimeout(res, ms));
}

function fnDefine(arr) { // some external params, whatever
  return async function work(recurse, resolve, reject) { // <<< API defined
    await delay(100);
    const num = Math.random();
    const more = (num > .5); // arbitrary condition
    if (!more) {
      resolve(arr); // end recursion
      return;
    }
    arr.push(num);
    const ms = 100;
    recurse(ms); // execute recursion
  }
}

async function fnRecurse(work) {
  async function main(resolve, reject) {
    // recursion defined: execute main with (resolve, reject)
    const recurse = (ms = 1) => setTimeout(main, ms, resolve, reject);
    try {
      await work(recurse, resolve, reject); // <<< API executed
    }
    catch (err) { reject(err); }
  }
  return new Promise(main);
}

// test:
// const result = await fnRecurse(fnDefine([]))
// fnRecurse(fnDefine([])).then(console.log)