elcodabra · January 31, 2022 12:38 · Jan 31, 2022
diff --git a/events.spec.ts b/events.spec.ts
@@ -0,0 +1,24 @@
+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)
+  })
+})
diff --git a/events.ts b/events.ts
@@ -0,0 +1,54 @@
+
+// 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