worker-message-decorator

/// <reference lib="webworker" />

interface IMessageEvent<T> {
  name: string;
  payload: T;
}

function PostMessage(eventName: string) {
  return function (target: any, propertyKey: string, descriptor: PropertyDescriptor) {
    const originalMethod = descriptor.value;
    descriptor.value = function () {
      const context = this;
      const result = originalMethod.apply(context, arguments);
      postMessage({name: eventName, payload: result});
      return result;
    }

    return descriptor;
  }
}

function OnMessage(eventName: string) {
  return function (target: any, propertyKey: string, descriptor: PropertyDescriptor) {
    const internalMethodName = `__OnMessage${eventName}`;
    target[internalMethodName] = descriptor.value;

    return descriptor;
  }
}

function Messageable<T extends { new(...args: any[]): {} }>(constructor: T) {
  return class extends constructor {
    constructor(...args: any[]) {
      super(...args);
      addEventListener('message', this.__messageDistributor.bind(this));
    }
    // @ts-ignore
    __messageDistributor({ data }) {
      if (data.name) {
        const theoreticalMethodName = `__OnMessage${data.name}`;
        // @ts-ignore
        if (typeof this[theoreticalMethodName] === 'function') {
          // @ts-ignore
          this[theoreticalMethodName].apply(this, [data.payload]);
        }
      }
    }
  }
}

@Messageable
class MyWorker {
  foo = 'bar';
  o: string;
  constructor(v: string, private p: string) {
    this.o = v;
  }

  @PostMessage('bar')
  test(value: string) {
    console.log('test value', value);
    console.log('test this.foo', this.foo);
    console.log('test this.o', this.o);
    console.log('test this.p', this.p);
    return `${this.foo} - 0${value}`;
  }

  @OnMessage('hello')
  listener(data: any) {
    console.log('listener', this);
    console.log('listener data', data);
    console.log('listener this.foo', this.foo);
    console.log('listener this.o', this.o);
    console.log('listener this.p', this.p);
    setTimeout(() => {
      this.test(`1${this.foo} - 2${this.o} - 3${this.p} - 4${data.fuur}`);
    }, 1000);

  }
}

const w = new MyWorker('aaaa', 'bbbbb');