Added custom event emitter

src/main/libs/Emitter.ts

@@ -0,0 +1,39 @@
+import { EventEmitter } from 'events';
+
+/**
+ * Example Usage of custom emitter class
+ *
+ * type TestMap = {
+ *     start: { total: number },
+ *     end: { bytes: number },
+ *     data: {bytes: number, total: number, percentage: number, file: string }
+ * };
+ *
+ * const testEmitter = new MyEmitter<TestMap>();
+ * testEmitter.on('start', (params) => {
+ *     console.log('start', params);
+ * });
+ */
+
+type EventMap = Record<string, any>;
+type EventKey<T extends EventMap> = string & keyof T;
+type EventReceiver<T> = (params: T) => void;
+
+export default class Emitter<T extends EventMap> {
+  private emitter = new EventEmitter();
+
+  on<K extends EventKey<T>>(eventName: K, fn: EventReceiver<T[K]>) {
+    this.emitter.on(eventName, fn);
+  }
+
+  off<K extends EventKey<T>>(eventName: K, fn: EventReceiver<T[K]>) {
+    this.emitter.off(eventName, fn);
+  }
+
+  emit<K extends EventKey<T>>(eventName: K, params: T[K]) {
+    this.emitter.emit(eventName, params);
+  }
+
+}
+
+