fix(kafkaTrigger Node): fix kafka trigger not working with default max requests value

packages/nodes-base/credentials/Kafka.credentials.ts

@@ -11,6 +11,7 @@ export class Kafka implements ICredentialType {
 			type: 'string',
 			default: '',
 			placeholder: 'my-app',
+			hint: 'Will not affect the connection, but will be used to identify the client in the Kafka server logs. Read more <a href="https://kafka.apache.org/documentation/#design_quotasgroups">here</a>',
 		},
 		{
 			displayName: 'Brokers',

packages/nodes-base/nodes/Kafka/Kafka.node.ts

@@ -11,7 +11,11 @@ import { SchemaRegistry } from '@kafkajs/confluent-schema-registry';
 import { IExecuteFunctions } from 'n8n-core';
 
 import {
+	ICredentialDataDecryptedObject,
+	ICredentialsDecrypted,
+	ICredentialTestFunctions,
 	IDataObject,
+	INodeCredentialTestResult,
 	INodeExecutionData,
 	INodeType,
 	INodeTypeDescription,
@@ -35,6 +39,7 @@ export class Kafka implements INodeType {
 			{
 				name: 'kafka',
 				required: true,
+				testedBy: 'kafkaConnectionTest',
 			},
 		],
 		properties: [
@@ -185,6 +190,56 @@ export class Kafka implements INodeType {
 		],
 	};
 
+	methods = {
+		credentialTest: {
+			async kafkaConnectionTest(
+				this: ICredentialTestFunctions,
+				credential: ICredentialsDecrypted,
+			): Promise<INodeCredentialTestResult> {
+				const credentials = credential.data as ICredentialDataDecryptedObject;
+				try {
+					const brokers = ((credentials.brokers as string) || '')
+						.split(',')
+						.map((item) => item.trim()) as string[];
+
+					const clientId = credentials.clientId as string;
+
+					const ssl = credentials.ssl as boolean;
+
+					const config: KafkaConfig = {
+						clientId,
+						brokers,
+						ssl,
+					};
+					if (credentials.authentication === true) {
+						if (!(credentials.username && credentials.password)) {
+							throw Error('Username and password are required for authentication');
+						}
+						config.sasl = {
+							username: credentials.username as string,
+							password: credentials.password as string,
+							mechanism: credentials.saslMechanism as string,
+						} as SASLOptions;
+					}
+
+					const kafka = new apacheKafka(config);
+
+					await kafka.admin().connect();
+					await kafka.admin().disconnect();
+					return {
+						status: 'OK',
+						message: 'Authentication successful',
+					};
+				} catch (error) {
+					return {
+						status: 'Error',
+						message: error.message,
+					};
+				}
+			},
+		},
+	};
+
 	async execute(this: IExecuteFunctions): Promise<INodeExecutionData[][]> {
 		const items = this.getInputData();
 

packages/nodes-base/nodes/Kafka/KafkaTrigger.node.ts

@@ -114,7 +114,7 @@ export class KafkaTrigger implements INodeType {
 						displayName: 'Max Number of Requests',
 						name: 'maxInFlightRequests',
 						type: 'number',
-						default: 0,
+						default: 1,
 						description:
 							'Max number of requests that may be in progress at any time. If falsey then no limit.',
 					},
@@ -202,9 +202,15 @@ export class KafkaTrigger implements INodeType {
 
 		const kafka = new apacheKafka(config);
 
+		const maxInFlightRequests = (
+			this.getNodeParameter('options.maxInFlightRequests', null) === 0
+				? null
+				: this.getNodeParameter('options.maxInFlightRequests', null)
+		) as number;
+
 		const consumer = kafka.consumer({
 			groupId,
-			maxInFlightRequests: this.getNodeParameter('options.maxInFlightRequests', 0) as number,
+			maxInFlightRequests,
 			sessionTimeout: this.getNodeParameter('options.sessionTimeout', 30000) as number,
 			heartbeatInterval: this.getNodeParameter('options.heartbeatInterval', 3000) as number,
 		});