feat: Support thinking settings for Gemini models (#19591)

packages/@n8n/nodes-langchain/nodes/llms/LmChatGoogleVertex/test/LmChatGoogleVertex.test.ts

@@ -0,0 +1,149 @@
+import { ChatVertexAI } from '@langchain/google-vertexai';
+import { createMockExecuteFunction } from 'n8n-nodes-base/test/nodes/Helpers';
+import type { INode, ISupplyDataFunctions } from 'n8n-workflow';
+
+import { makeN8nLlmFailedAttemptHandler } from '../../n8nLlmFailedAttemptHandler';
+import { N8nLlmTracing } from '../../N8nLlmTracing';
+import { LmChatGoogleVertex } from '../LmChatGoogleVertex.node';
+
+jest.mock('@langchain/google-vertexai');
+jest.mock('../../N8nLlmTracing');
+jest.mock('../../n8nLlmFailedAttemptHandler');
+jest.mock('n8n-nodes-base/dist/utils/utilities', () => ({
+	formatPrivateKey: jest.fn().mockImplementation((key: string) => key),
+}));
+
+const MockedChatVertexAI = jest.mocked(ChatVertexAI);
+const MockedN8nLlmTracing = jest.mocked(N8nLlmTracing);
+const mockedMakeN8nLlmFailedAttemptHandler = jest.mocked(makeN8nLlmFailedAttemptHandler);
+
+describe('LmChatGoogleVertex - Thinking Budget', () => {
+	let lmChatGoogleVertex: LmChatGoogleVertex;
+	let mockContext: jest.Mocked<ISupplyDataFunctions>;
+
+	const mockNode: INode = {
+		id: '1',
+		name: 'Google Vertex Chat Model',
+		typeVersion: 1,
+		type: 'n8n-nodes-langchain.lmChatGoogleVertex',
+		position: [0, 0],
+		parameters: {},
+	};
+
+	const setupMockContext = () => {
+		mockContext = createMockExecuteFunction<ISupplyDataFunctions>(
+			{},
+			mockNode,
+		) as jest.Mocked<ISupplyDataFunctions>;
+
+		mockContext.getCredentials = jest.fn().mockResolvedValue({
+			privateKey: 'test-private-key',
+			email: 'test@n8n.io',
+			region: 'us-central1',
+		});
+		mockContext.getNode = jest.fn().mockReturnValue(mockNode);
+		mockContext.getNodeParameter = jest.fn();
+
+		MockedN8nLlmTracing.mockImplementation(() => ({}) as unknown as N8nLlmTracing);
+		mockedMakeN8nLlmFailedAttemptHandler.mockReturnValue(jest.fn());
+
+		return mockContext;
+	};
+
+	beforeEach(() => {
+		lmChatGoogleVertex = new LmChatGoogleVertex();
+		jest.clearAllMocks();
+	});
+
+	afterEach(() => {
+		jest.clearAllMocks();
+	});
+
+	describe('supplyData - thinking budget parameter passing', () => {
+		it('should not include thinkingBudget in model config when not specified', async () => {
+			const mockContext = setupMockContext();
+
+			mockContext.getNodeParameter = jest.fn().mockImplementation((paramName: string) => {
+				if (paramName === 'modelName') return 'gemini-2.5-flash';
+				if (paramName === 'projectId') return 'test-project';
+				if (paramName === 'options') {
+					// Return options without thinkingBudget
+					return {
+						maxOutputTokens: 2048,
+						temperature: 0.4,
+						topK: 40,
+						topP: 0.9,
+					};
+				}
+				if (paramName === 'options.safetySettings.values') return null;
+				return undefined;
+			});
+
+			await lmChatGoogleVertex.supplyData.call(mockContext, 0);
+			expect(MockedChatVertexAI).toHaveBeenCalledTimes(1);
+			const callArgs = MockedChatVertexAI.mock.calls[0][0];
+			expect(callArgs).not.toHaveProperty('thinkingBudget');
+			expect(callArgs).toMatchObject({
+				authOptions: {
+					projectId: 'test-project',
+					credentials: {
+						client_email: 'test@n8n.io',
+						private_key: 'test-private-key',
+					},
+				},
+				location: 'us-central1',
+				model: 'gemini-2.5-flash',
+				topK: 40,
+				topP: 0.9,
+				temperature: 0.4,
+				maxOutputTokens: 2048,
+			});
+		});
+
+		it('should include thinkingBudget in model config when specified', async () => {
+			const mockContext = setupMockContext();
+			const expectedThinkingBudget = 1024;
+
+			mockContext.getNodeParameter = jest.fn().mockImplementation((paramName: string) => {
+				if (paramName === 'modelName') return 'gemini-2.5-flash';
+				if (paramName === 'projectId') return 'test-project';
+				if (paramName === 'options') {
+					// Return options with thinkingBudget
+					return {
+						maxOutputTokens: 2048,
+						temperature: 0.4,
+						topK: 40,
+						topP: 0.9,
+						thinkingBudget: expectedThinkingBudget,
+					};
+				}
+				if (paramName === 'options.safetySettings.values') return null;
+				return undefined;
+			});
+
+			await lmChatGoogleVertex.supplyData.call(mockContext, 0);
+			expect(MockedChatVertexAI).toHaveBeenCalledWith(
+				expect.objectContaining({
+					authOptions: {
+						projectId: 'test-project',
+						credentials: {
+							client_email: 'test@n8n.io',
+							private_key: 'test-private-key',
+						},
+					},
+					location: 'us-central1',
+					model: 'gemini-2.5-flash',
+					topK: 40,
+					topP: 0.9,
+					temperature: 0.4,
+					maxOutputTokens: 2048,
+					thinkingBudget: expectedThinkingBudget,
+					// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+					callbacks: expect.arrayContaining([expect.any(Object)]),
+					// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+					onFailedAttempt: expect.any(Function),
+				}),
+			);
+		});
+	});
+});