Reactor Extended

events.spec.ts

import Reactor from './events'

describe('Reactor: Events Management System', () => {
  const eventName = 'onError'
  const reactor = new (Reactor as any)()

  it(`registers window.${eventName} with callbacks`, () => {
    // reactor.registerEvent(eventName)
    const callback1 = jest.fn(() => console.log('callback 1'))
    const callback2 = jest.fn(() => console.log('callback 2'))

    reactor.addEventListener(eventName, callback1)
    reactor.addEventListener(eventName, callback2)

    // reactor.dispatchEvent(eventName)
    ;(window as any)[eventName]() // 2 results
    reactor.removeEventListener(eventName, callback2)
    // reactor.dispatchEvent(eventName)
    ;(window as any)[eventName]() // 1 result

    expect(callback1).toHaveBeenCalledTimes(2)
    expect(callback2).toHaveBeenCalledTimes(1)
  })
})

events.ts

// https://gist.github.com/mohsen1/5123533
import { common } from '@material-ui/core/colors'

function Reactor() {
  // @ts-ignore
  this.events = {}
}

Reactor.prototype.registerEvent = function(eventName: string) {
  this.events[eventName] = new (Event as any)(eventName)
}

Reactor.prototype.dispatchEvent = function(eventName: string, eventArgs: any) {
  this.events[eventName].callbacks.forEach((callback: (e: any) => void) => {
    callback(eventArgs)
  })
}

Reactor.prototype.addEventListener = function(eventName: string, callback: (e: any) => void) {
  if (!this.events[eventName]) {
    this.registerEvent(eventName)
  }
  this.events[eventName].registerCallback(callback)
}

Reactor.prototype.removeEventListener = function(eventName: string, callback: (e: any) => void) {
  if (!this.events[eventName]) return
  this.events[eventName].unregisterCallback(callback)
}

export function Event(name: string) {
  // @ts-ignore
  this.name = name
  // @ts-ignore
  this.callbacks = []

  ;(window as any)[name] = (e: any) => {
    // @ts-ignore
    this.callbacks.forEach(callback => {
      callback(e)
    })
  }
}

Event.prototype.registerCallback = function(callback: (e: any) => void) {
  this.callbacks.push(callback)
}

Event.prototype.unregisterCallback = function(callback: (e: any) => void) {
  this.callbacks.pop(callback)
}

export default Reactor