worker-manager.ts

export class UnitWorkerManager {
  private resolves = {}
  private rejects = {}
  private promiseId = 0
  private worker

  constructor(scriptPath, opts) {
    this.worker = new Worker(scriptPath, opts)
    this.worker.addEventListener('message', data => {
      const { id, err, result } = data || {}
      if (!id) throw `Received message from web worker without id!`
      const resolve = this.resolves[id]
      const reject = this.rejects[id]
      if (err && reject) {
        reject(err)
      } else if (result && resolve) {
        resolve(result)
      }
    })
    this.worker.addEventListener('error', err => {
      throw err
    })
  }

  async request<T>(args): Promise<T> {
    const id = ++this.promiseId
    const result = await new Promise((resolve, reject) => {
      this.resolves[id] = resolve
      this.rejects[id] = reject
      this.worker.postMessage({ id, args })
    })
    return result as T
  }
}