register and unregister for every iteration

packages/reactivity-core/TaskQueue.ts

@@ -14,10 +14,7 @@ export class TaskQueue {
     private queue: Task[] = [];
     private channel = new MessageChannel();
 
-    constructor() {
-        // https://stackoverflow.com/a/61574326
-        this.channel.port2.onmessage = () => this.runIteration();
-    }
+    constructor() {}
 
     /**
      * Enqueues a function to be executed in the next task queue iteration.
@@ -53,11 +50,18 @@ export class TaskQueue {
         };
     }
 
+    private messageHandler = () => this.runIteration();
     private scheduleIteration() {
+        // register and unregister for every iteration otherwise node will not terminate
+        // https://stackoverflow.com/a/61574326
+        this.channel.port2.addEventListener("message", this.messageHandler);
+
         this.channel.port1.postMessage(""); // queue macro task
     }
 
     private runIteration() {
+        this.channel.port2.removeEventListener("message", this.messageHandler);
+
         // Swap arrays so that NEW tasks are not queued into the same array;
         // they will be handled in the next iteration.
         const tasks = this.queue;