fix(Kafka Node): Upgrade kafkajs and add tests (#14326)

Co-authored-by: Dana Lee <dana@n8n.io>

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

@@ -0,0 +1,105 @@
+import { SchemaRegistry } from '@kafkajs/confluent-schema-registry';
+import { mock } from 'jest-mock-extended';
+import type { Producer } from 'kafkajs';
+import { Kafka as apacheKafka } from 'kafkajs';
+import path from 'path';
+
+import { getWorkflowFilenames, testWorkflows } from '@test/nodes/Helpers';
+
+jest.mock('kafkajs');
+jest.mock('@kafkajs/confluent-schema-registry');
+
+describe('Kafka Node', () => {
+	let mockProducer: jest.Mocked<Producer>;
+	let mockKafka: jest.Mocked<apacheKafka>;
+	let mockRegistry: jest.Mocked<SchemaRegistry>;
+	let mockProducerConnect: jest.Mock;
+	let mockProducerSend: jest.Mock;
+	let mockProducerDisconnect: jest.Mock;
+	let mockRegistryEncode: jest.Mock;
+
+	beforeAll(() => {
+		mockProducerConnect = jest.fn();
+		mockProducerSend = jest.fn().mockImplementation(async () => []);
+		mockProducerDisconnect = jest.fn();
+
+		mockProducer = mock<Producer>({
+			connect: mockProducerConnect,
+			send: mockProducerSend,
+			sendBatch: mockProducerSend,
+			disconnect: mockProducerDisconnect,
+		});
+
+		mockKafka = mock<apacheKafka>({
+			producer: jest.fn().mockReturnValue(mockProducer),
+		});
+
+		mockRegistryEncode = jest.fn((_id, input) => Buffer.from(JSON.stringify(input)));
+		mockRegistry = mock<SchemaRegistry>({
+			encode: mockRegistryEncode,
+		});
+
+		(apacheKafka as jest.Mock).mockReturnValue(mockKafka);
+		(SchemaRegistry as jest.Mock).mockReturnValue(mockRegistry);
+	});
+
+	const workflows = getWorkflowFilenames(path.join(__dirname, 'test'));
+	testWorkflows(workflows);
+
+	test('should publish the correct kafka messages', async () => {
+		expect(mockProducerSend).toHaveBeenCalledTimes(2);
+		expect(mockProducerSend).toHaveBeenCalledWith({
+			acks: 1,
+			compression: 1,
+			timeout: 1000,
+			topicMessages: [
+				{
+					messages: [
+						{
+							headers: { header: 'value' },
+							key: 'messageKey',
+							value: '{"name":"First item","code":1}',
+						},
+					],
+					topic: 'test-topic',
+				},
+				{
+					messages: [
+						{
+							headers: { header: 'value' },
+							key: 'messageKey',
+							value: '{"name":"Second item","code":2}',
+						},
+					],
+					topic: 'test-topic',
+				},
+			],
+		});
+		expect(mockProducerSend).toHaveBeenCalledWith({
+			acks: 0,
+			compression: 0,
+			topicMessages: [
+				{
+					messages: [
+						{
+							headers: { headerKey: 'headerValue' },
+							key: null,
+							value: Buffer.from(JSON.stringify({ foo: 'bar' })),
+						},
+					],
+					topic: 'test-topic',
+				},
+				{
+					messages: [
+						{
+							headers: { headerKey: 'headerValue' },
+							key: null,
+							value: Buffer.from(JSON.stringify({ foo: 'bar' })),
+						},
+					],
+					topic: 'test-topic',
+				},
+			],
+		});
+	});
+});