feat: Implement streaming response node on ChatTrigger and Webhook (no-changelog) (#16761)

packages/nodes-base/nodes/Webhook/test/Webhook.test.ts

@@ -1,5 +1,5 @@
 import { NodeTestHarness } from '@nodes-testing/node-test-harness';
-import type { Request } from 'express';
+import type { Request, Response } from 'express';
 import { mock } from 'jest-mock-extended';
 import type { IWebhookFunctions } from 'n8n-workflow';
 
@@ -40,4 +40,93 @@ describe('Test Webhook Node', () => {
 			expect(context.nodeHelpers.copyBinaryFile).toHaveBeenCalled();
 		});
 	});
+
+	describe('streaming response mode', () => {
+		const node = new Webhook();
+		const context = mock<IWebhookFunctions>({
+			nodeHelpers: mock(),
+		});
+		const req = mock<Request>();
+		const res = mock<Response>();
+
+		beforeEach(() => {
+			jest.clearAllMocks();
+			context.getRequestObject.mockReturnValue(req);
+			context.getResponseObject.mockReturnValue(res);
+			context.getChildNodes.mockReturnValue([]);
+			context.getNode.mockReturnValue({
+				type: 'n8n-nodes-base.webhook',
+				typeVersion: 2,
+				name: 'Webhook',
+			} as any);
+			context.getNodeParameter.mockImplementation((paramName: string) => {
+				if (paramName === 'options') return {};
+				if (paramName === 'responseMode') return 'streaming';
+				return undefined;
+			});
+			req.headers = {};
+			req.params = {};
+			req.query = {};
+			req.body = { message: 'test' };
+			Object.defineProperty(req, 'ips', { value: [], configurable: true });
+			Object.defineProperty(req, 'ip', { value: '127.0.0.1', configurable: true });
+			res.writeHead.mockImplementation(() => res);
+			res.flushHeaders.mockImplementation(() => undefined);
+		});
+
+		it('should enable streaming when responseMode is "streaming"', async () => {
+			const result = await node.webhook(context);
+
+			// Verify streaming headers are set
+			expect(res.writeHead).toHaveBeenCalledWith(200, {
+				'Content-Type': 'application/json; charset=utf-8',
+				'Transfer-Encoding': 'chunked',
+				'Cache-Control': 'no-cache',
+				Connection: 'keep-alive',
+			});
+			expect(res.flushHeaders).toHaveBeenCalled();
+
+			// Verify response structure for streaming
+			expect(result).toEqual({
+				noWebhookResponse: true,
+				workflowData: expect.any(Array),
+			});
+		});
+
+		it('should not enable streaming when responseMode is not "streaming"', async () => {
+			context.getNodeParameter.mockImplementation((paramName: string) => {
+				if (paramName === 'options') return {};
+				if (paramName === 'responseMode') return 'onReceived';
+				return undefined;
+			});
+
+			const result = await node.webhook(context);
+
+			// Verify streaming headers are NOT set
+			expect(res.writeHead).not.toHaveBeenCalled();
+			expect(res.flushHeaders).not.toHaveBeenCalled();
+
+			// Verify normal response structure
+			expect(result).toEqual({
+				webhookResponse: undefined,
+				workflowData: expect.any(Array),
+			});
+		});
+
+		it('should handle multipart form data with streaming enabled', async () => {
+			req.contentType = 'multipart/form-data';
+			req.body = {
+				data: { message: 'Hello' },
+				files: {},
+			};
+
+			const result = await node.webhook(context);
+
+			// For multipart form data, streaming is handled in handleFormData method
+			// The current implementation returns normal workflowData for form data
+			expect(result).toEqual({
+				workflowData: expect.any(Array),
+			});
+		});
+	});
 });