Refactor close function and handle errors properly

This commit refactors the close function for producers and consumers by removing the unnecessary assignment to 'self'. With this refactor, we'll directly use the 'node' object to close the consumer, producer, or client. Furthermore, it improves error handling in the producer by using 'node.error' instead of 'node.debug', which is more appropriate for displaying error messages.

src/pulsar-config.js

@@ -1,6 +1,10 @@
 module.exports = function(RED) {
     function PulsarConfigNode(n) {
         RED.nodes.createNode(this,n);
+        const node = this;
+        node.on('close', function() {
+            node.client && node.client.close();
+        });
         try {
             const Pulsar = require('pulsar-client');
             this.client = new Pulsar.Client({

src/pulsar-consumer.js

@@ -128,8 +128,7 @@ module.exports = function(RED) {
         node.producerConfig = producerConfig;
 
         node.on('close', async function() {
-            const self = this;
-            self.consumer && await self.consumer.close();
+            node.consumer && await node.consumer.close();
         });
         node.status({fill: "red", shape: "dot", text: "disconnected"});
 

src/pulsar-producer.js

@@ -73,9 +73,8 @@ module.exports = function (RED) {
         }
         node.producerConfig = producerConfig;
 
-        node.on('close', async function() {
-            const self = this;
-            self.producer && await self.producer.close();
+        node.on('close', function() {
+            node.producer && node.producer.close();
         });
         node.status({fill: "red", shape: "dot", text: "disconnected"});
 
@@ -104,7 +103,7 @@ module.exports = function (RED) {
             };
             node.send(message);
         }).catch(e => {
-            node.debug('Error creating producer: ' + e);
+            node.error('Error creating producer: ' + e);
             node.status({fill: "red", shape: "dot", text: "Connection error"});
         });