async-queue.mjs

export class Queue {
  #buffer = [];
  #p = Promise.withResolvers();
  #stopped = false;

  push(value) {
    if (this.#stopped) throw new Error('Queue is stopped');
    this.#buffer.push(value);
    this.#p.resolve();
  }

  stop() {
    this.#stopped = true;
    this.#p.resolve();
  }

  async *read() {
    while (true) {
      while (this.#buffer.length > 0) yield this.#buffer.shift();
      if (this.#stopped) return;
      await this.#p.promise;
      this.#p = Promise.withResolvers();
    }
  }
}