fix: AsyncSRT types and tests, add super() to AsyncSRT constructor (#67)

* add event emitter to async class

* fix types for AsyncSRT class

* Should call super() on constructor as extending event emitter, fixes tests

src/async.js

@@ -25,7 +25,7 @@ class AsyncSRT extends EventEmitter {
   static TimeoutMs = DEFAULT_PROMISE_TIMEOUT_MS;
 
   constructor() {
-
+    super()
     DEBUG && debug('Creating task-runner worker instance');
 
     this._worker = new Worker(path.resolve(__dirname, './async-worker.js'));

types/srt-api-async.d.ts

@@ -1,11 +1,11 @@
-
+import { EventEmitter } from "events";
 import { SRTLoggingLevel, SRTResult, SRTSockOpt, SRTSockStatus } from "../src/srt-api-enums";
 
 import { SRTReadReturn, SRTFileDescriptor, SRTEpollEvent, SRTSockOptValue, SRTStats } from "./srt-api"
 
 export type AsyncSRTCallback<T> = (result: T) => void;
 
-export class AsyncSRT {
+export class AsyncSRT extends EventEmitter {
 
   static TimeoutMs: number;