refactor(Structured Output Parser Node): Support schema via expression (#16671)

packages/@n8n/nodes-langchain/utils/output_parsers/N8nOutputParser.test.ts

@@ -0,0 +1,101 @@
+import { mock } from 'jest-mock-extended';
+import type { IExecuteFunctions } from 'n8n-workflow';
+import { NodeConnectionTypes } from 'n8n-workflow';
+
+import { getOptionalOutputParser } from './N8nOutputParser';
+import type { N8nStructuredOutputParser } from './N8nStructuredOutputParser';
+
+describe('getOptionalOutputParser', () => {
+	let mockContext: jest.Mocked<IExecuteFunctions>;
+
+	beforeEach(() => {
+		mockContext = mock<IExecuteFunctions>();
+		jest.clearAllMocks();
+	});
+
+	it('should return undefined when hasOutputParser is false', async () => {
+		mockContext.getNodeParameter.mockReturnValue(false);
+
+		const result = await getOptionalOutputParser(mockContext);
+
+		expect(result).toBeUndefined();
+		expect(mockContext.getNodeParameter).toHaveBeenCalledWith('hasOutputParser', 0, true);
+		expect(mockContext.getInputConnectionData).not.toHaveBeenCalled();
+	});
+
+	it('should return output parser when hasOutputParser is true with default index', async () => {
+		const mockParser = mock<N8nStructuredOutputParser>();
+		mockContext.getNodeParameter.mockReturnValue(true);
+		mockContext.getInputConnectionData.mockResolvedValue(mockParser);
+
+		const result = await getOptionalOutputParser(mockContext);
+
+		expect(result).toBe(mockParser);
+		expect(mockContext.getNodeParameter).toHaveBeenCalledWith('hasOutputParser', 0, true);
+		expect(mockContext.getInputConnectionData).toHaveBeenCalledWith(
+			NodeConnectionTypes.AiOutputParser,
+			0,
+		);
+	});
+
+	it('should use provided index when fetching output parser', async () => {
+		const mockParser = mock<N8nStructuredOutputParser>();
+		mockContext.getNodeParameter.mockReturnValue(true);
+		mockContext.getInputConnectionData.mockResolvedValue(mockParser);
+
+		const result = await getOptionalOutputParser(mockContext, 2);
+
+		expect(result).toBe(mockParser);
+		expect(mockContext.getNodeParameter).toHaveBeenCalledWith('hasOutputParser', 0, true);
+		expect(mockContext.getInputConnectionData).toHaveBeenCalledWith(
+			NodeConnectionTypes.AiOutputParser,
+			2,
+		);
+	});
+
+	it('should handle different index values correctly', async () => {
+		const mockParser1 = mock<N8nStructuredOutputParser>();
+		const mockParser2 = mock<N8nStructuredOutputParser>();
+		const mockParser3 = mock<N8nStructuredOutputParser>();
+
+		mockContext.getNodeParameter.mockReturnValue(true);
+		mockContext.getInputConnectionData
+			.mockResolvedValueOnce(mockParser1)
+			.mockResolvedValueOnce(mockParser2)
+			.mockResolvedValueOnce(mockParser3);
+
+		const result1 = await getOptionalOutputParser(mockContext, 0);
+		const result2 = await getOptionalOutputParser(mockContext, 1);
+		const result3 = await getOptionalOutputParser(mockContext, 5);
+
+		expect(result1).toBe(mockParser1);
+		expect(result2).toBe(mockParser2);
+		expect(result3).toBe(mockParser3);
+
+		expect(mockContext.getInputConnectionData).toHaveBeenNthCalledWith(
+			1,
+			NodeConnectionTypes.AiOutputParser,
+			0,
+		);
+		expect(mockContext.getInputConnectionData).toHaveBeenNthCalledWith(
+			2,
+			NodeConnectionTypes.AiOutputParser,
+			1,
+		);
+		expect(mockContext.getInputConnectionData).toHaveBeenNthCalledWith(
+			3,
+			NodeConnectionTypes.AiOutputParser,
+			5,
+		);
+	});
+
+	it('should always check hasOutputParser at index 0', async () => {
+		mockContext.getNodeParameter.mockReturnValue(false);
+
+		await getOptionalOutputParser(mockContext, 3);
+
+		// Even when called with index 3, hasOutputParser is checked at index 0
+		expect(mockContext.getNodeParameter).toHaveBeenCalledWith('hasOutputParser', 0, true);
+		expect(mockContext.getInputConnectionData).not.toHaveBeenCalled();
+	});
+});

packages/@n8n/nodes-langchain/utils/output_parsers/N8nOutputParser.ts

@@ -14,13 +14,14 @@ export { N8nOutputFixingParser, N8nItemListOutputParser, N8nStructuredOutputPars
 
 export async function getOptionalOutputParser(
 	ctx: IExecuteFunctions,
+	index: number = 0,
 ): Promise<N8nOutputParser | undefined> {
 	let outputParser: N8nOutputParser | undefined;
 
 	if (ctx.getNodeParameter('hasOutputParser', 0, true) === true) {
 		outputParser = (await ctx.getInputConnectionData(
 			NodeConnectionTypes.AiOutputParser,
-			0,
+			index,
 		)) as N8nOutputParser;
 	}