feat(Think Tool Node): ToolThink, a simple tool to force the AI agent to do some thinking (#14351)

packages/@n8n/nodes-langchain/nodes/tools/ToolThink/test/ToolThink.node.test.ts

@@ -0,0 +1,34 @@
+import { mock } from 'jest-mock-extended';
+import { DynamicTool } from 'langchain/tools';
+import type { ISupplyDataFunctions } from 'n8n-workflow';
+
+import { ToolThink } from '../ToolThink.node';
+
+describe('ToolThink', () => {
+	const thinkTool = new ToolThink();
+	const helpers = mock<ISupplyDataFunctions['helpers']>();
+	const executeFunctions = mock<ISupplyDataFunctions>({
+		helpers,
+	});
+	executeFunctions.addInputData.mockReturnValue({ index: 0 });
+	executeFunctions.getNodeParameter.mockImplementation((paramName: string) => {
+		switch (paramName) {
+			case 'description':
+				return 'Tool description';
+			default:
+				return undefined;
+		}
+	});
+
+	describe('Tool response', () => {
+		it('should return the same text as response when receiving a text input', async () => {
+			const { response } = (await thinkTool.supplyData.call(executeFunctions, 0)) as {
+				response: DynamicTool;
+			};
+			expect(response).toBeInstanceOf(DynamicTool);
+			expect(response.description).toEqual('Tool description');
+			const res = (await response.invoke('foo')) as string;
+			expect(res).toEqual('foo');
+		});
+	});
+});