Add event system with metrics and typings

package.json

@@ -9,7 +9,7 @@
   "scripts": {
     "test": "jest src",
     "start": "node sample/publisher/index.js && node sample/subscriber/index.js && npx nuc-node-event-test/server",
-    "build": "npx tsc client/Event.ts --outDir client --declaration"
+    "build": "npx tsc client/Event.ts --outDir client --declaration && npx tsc src/Event.ts --outDir src --declaration"
   },
   "dependencies": {
     "chalk": "^4.1.2",
@@ -44,9 +44,9 @@
   },
   "exports": {
     ".": {
-      "import": "./src/Event.ts",
-      "require": "./src/Event.ts",
-      "types": "./src/Event.ts"
+      "import": "./src/Event.js",
+      "require": "./src/Event.js",
+      "types": "./src/Event.d.ts"
     },
     "./client": {
       "import": "./client/Event.js",

src/Event.ts

@@ -1,4 +1,5 @@
-import client from "prom-client";
+import * as client from "prom-client";
+
 import { v4 as uuid } from "uuid";
 
 const subscriptions = {};
@@ -23,44 +24,38 @@ const eventPublishDuration = new client.Histogram({
   buckets: [0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 5],
 });
 
-// Track payload size for analysis
 const eventPayloadSize = new client.Histogram({
   name: "event_payload_size_bytes",
   help: "Size of event payloads in bytes",
   labelNames: ["event_type"],
   buckets: [10, 100, 1000, 10000, 100000, 1000000],
 });
 
-// Track error rates
 const eventPublishErrors = new client.Counter({
   name: "event_publish_errors_total",
   help: "Total number of event publish errors",
   labelNames: ["event_type", "error_type"],
 });
 
-// Track callback processing duration
 const callbackProcessingDuration = new client.Histogram({
   name: "event_callback_duration_seconds",
   help: "Time taken to process event callbacks",
   labelNames: ["event_type"],
   buckets: [0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 5],
 });
 
-// Track subscription rates
 const subscriptionRate = new client.Counter({
   name: "event_subscriptions_total",
   help: "Total number of event subscriptions created",
   labelNames: ["event_type"],
 });
 
-// Track unsubscription rates
 const unsubscriptionRate = new client.Counter({
   name: "event_unsubscriptions_total",
   help: "Total number of event unsubscriptions",
   labelNames: ["event_type"],
 });
 
-// Track throughput (events processed per second)
 const eventThroughput = new client.Counter({
   name: "event_callbacks_processed_total",
   help: "Total number of event callbacks processed successfully",
@@ -119,7 +114,6 @@ const subscribe = (...args) => {
       console.debug("node-event", "unsubscribe", type, id);
       delete subscriptions[type][id];
 
-      // Track unsubscription
       unsubscriptionRate.labels(type).inc();
 
       if (Object.keys(subscriptions[type]).length === 0) {
@@ -135,7 +129,6 @@ const subscribe = (...args) => {
 
   subscriptions[type][id] = registry;
 
-  // Update subscription metrics
   subscriptionRate.labels(type).inc();
   eventSubscriptionGauge
     .labels(type)
@@ -159,11 +152,9 @@ const publish = (...args) => {
     throw new Error("Invalid publish type");
   }
 
-  // Track metrics for event publishing
   const endTimer = eventPublishDuration.labels(type).startTimer();
   eventPublishCounter.labels(type).inc();
 
-  // Track payload size
   const payloadSize = JSON.stringify(payload).length;
   eventPayloadSize.labels(type).observe(payloadSize);