Lets you queue up async tasks and executes them sequentially

async-task-queue.js

const queueTask = (() => {
  let pending = () => Promise.resolve();

  const run = async (fn) => {
    try {
      await pending;
    } finally {
      return fn();
    }
  };

  return (fn) => (pending = run(fn));
})();

Use like:

const wait = (ms) => {
  return new Promise((resolve) => setTimeout(resolve, ms));
};

queueTask(async () => {
  console.log("This will take 2 seconds");
  await wait(2000);
});

queueTask(async () => {
  console.log("This will take 3 seconds");
  await wait(3000);
});

queueTask(async () => {
  console.log("This will take 1 second");
  await wait(1000);
});

queueTask(async () => {
    console.log("Donezo!");
});