add testcases for event and changes on various files:

src/event.ts

@@ -30,7 +30,7 @@ export class DispatchableEvent implements IDispatcherEvent {
 
   /**
    * "This function adds a listener to the list of listeners."
-   * 
+   *
    * The first line of the function is the function declaration. It's a function named setListener that
    * takes a parameter named listener. The parameter is of type IDispatcherListener. The function
    * returns a DispatchableEvent

src/index.ts

@@ -2,4 +2,4 @@ import { DispatcherEngine } from './engine';
 import { DispatchableEvent } from './event';
 import { DispatchableListener } from './listener';
 
-export { DispatchableEvent, DispatchableListener, DispatcherEngine };
+export { DispatchableEvent, DispatchableListener, DispatcherEngine };

src/listener.ts

@@ -5,9 +5,9 @@ function so that it can be used as a listener */
 export class DispatchableListener implements IDispatcherListener {
   private _isOnce: boolean = false;
   private _expect: boolean = false;
-  private _listenerCallback: (args: object) => {};
+  private _listenerCallback: (args: object) => void;
 
-  constructor(listenerCallback: (args: object) => {}) {
+  constructor(listenerCallback: (args: object) => void) {
     this._listenerCallback = listenerCallback;
   }
 

tests/unit/event.test.ts

@@ -0,0 +1,28 @@
+import { DispatchableListener } from "../../src/listener";
+import { DispatchableEvent } from "../../src/event";
+
+describe('Dispatchable Event Suit', () => {    
+    test('setName() set event name', () => {
+        const dispatchableEvent = new DispatchableEvent('new-event');
+        dispatchableEvent.setName('new-event-name');
+        expect(typeof dispatchableEvent.setName).toBe('function');
+        expect(dispatchableEvent.getName()).toBe('new-event-name');
+    });
+
+    test('getName() return event name', () => {
+        const dispatchableEvent = new DispatchableEvent('new-event');
+        expect(typeof dispatchableEvent.getName).toBe('function');
+        expect(dispatchableEvent.getName()).toBe('new-event');
+    });
+
+    test('setListener() set listener in event', () => {
+        const dispatchableEvent = new DispatchableEvent('new-event');
+        const listener = new DispatchableListener((args) => {
+            return {}
+        });
+        dispatchableEvent.setListener(listener);
+
+        expect(typeof dispatchableEvent.setListener).toBe('function');
+        expect(dispatchableEvent.getListeners().length).toBe(1);
+    });
+})