export class RequestCoordinator {
  #versions = new Map()
  next(channel) {
    const version = (this.#versions.get(channel) || 0) + 1
    this.#versions.set(channel, version)
    return version
  }
  isCurrent(channel, version) { return this.#versions.get(channel) === version }
  async run(channel, ownerId, operation) {
    const version = this.next(channel)
    try {
      const value = await operation()
      return { accepted: this.isCurrent(channel, version), ownerId, value }
    } catch (error) {
      return { accepted: this.isCurrent(channel, version), ownerId, error }
    }
  }
  invalidate(channel) { return this.next(channel) }
}