fix: addEventListener & move for readability

packages/core/src/lib/filter/subscription.ts

@@ -74,26 +74,6 @@ export class Subscription extends EventEmitter<SubscriptionEventMap> {
     this.processSubscribeResponse(response, decoders);
   }
 
-  addEventListener<K extends string | number>(
-    type: K,
-    listener: EventHandler<SubscriptionEventMap[K]> | null,
-    options?: boolean | AddEventListenerOptions | undefined
-  ): void {
-    if (type !== "string")
-      throw new Error(
-        "Invalid event type. Expected content topic which should be a string."
-      );
-
-    const decoder = this.decoders.get(type);
-    if (!decoder) throw new Error("No decoder found for content topic " + type);
-    if (decoder.pubsubTopic !== this.pubsubTopic)
-      throw new Error(
-        `Invalid decoder received. Expected decoder for pubsub topic ${this.pubsubTopic} but received decoder for pubsub topic ${decoder.pubsubTopic}`
-      );
-
-    super.addEventListener(type, listener, options);
-  }
-
   async unsubscribe(contentTopics: ContentTopic[]): Promise<void> {
     const stream = await this.newStream(this.peer);
     const unsubscribeRequest = FilterSubscribeRpc.createUnsubscribeRequest(
@@ -193,6 +173,27 @@ export class Subscription extends EventEmitter<SubscriptionEventMap> {
     }
   }
 
+  addEventListener<K extends string | number>(
+    contentTopic: K,
+    listener: EventHandler<SubscriptionEventMap[K]> | null,
+    options?: boolean | AddEventListenerOptions | undefined
+  ): void {
+    if (typeof contentTopic !== "string")
+      throw new Error(
+        `Invalid event type. Expected content topic which should be a string but received ${contentTopic} of the type ${typeof contentTopic}`
+      );
+
+    const decoder = this.decoders.get(contentTopic);
+    if (!decoder)
+      throw new Error("No decoder found for content topic " + contentTopic);
+    if (decoder.pubsubTopic !== this.pubsubTopic)
+      throw new Error(
+        `Invalid decoder received. Expected decoder for pubsub topic ${this.pubsubTopic} but received decoder for pubsub topic ${decoder.pubsubTopic}`
+      );
+
+    super.addEventListener(contentTopic, listener, options);
+  }
+
   async processMessage(message: WakuMessage): Promise<void> {
     const { contentTopic } = message;
     if (!contentTopic) {