Enable socket to be closed

Author: andreterron

src/DenoWorker.ts

@@ -419,6 +419,16 @@ export class DenoWorker {
         return this._postMessage(null, data, transfer);
     }
 
+    /**
+     * Closes the websocket, which may allow the process to exit natually.
+     */
+    closeSocket() {
+        if (this._socket) {
+            this._socket.close();
+            this._socket = null;
+        }
+    }
+
     /**
      * Terminates the worker and cleans up unused resources.
      */