promises.ts

import PQueueMod from "p-queue";

let queue: typeof import("p-queue")["default"]["prototype"];

/**
 * Creates a queue using the p-queue library. The queue is configured to
 * auto-start and has a concurrency of 1, meaning it will process tasks
 * one at a time.
 */
function createQueue() {
  const PQueue = "default" in PQueueMod ? PQueueMod.default : PQueueMod;
  return new PQueue({
    autoStart: true,
    concurrency: 1,
  });
}

/**
 * Consume a promise, either adding it to the queue or waiting for it to resolve
 * @param promise Promise to consume
 * @param wait Whether to wait for the promise to resolve or resolve immediately
 */
export async function consumeCallback<T>(
  promiseFn: () => Promise<T> | T | void,
  wait: boolean
): Promise<void> {
  if (wait === true) {
    await promiseFn();
  } else {
    if (typeof queue === "undefined") {
      queue = createQueue();
    }
    void queue.add(promiseFn);
  }
}

/**
 * Waits for all promises in the queue to resolve. If the queue is
 * undefined, it immediately resolves a promise.
 */
export function awaitAllCallbacks(): Promise<void> {
  return typeof queue !== "undefined" ? queue.onIdle() : Promise.resolve();
}