fix(Code Node): Consistent redirection of stdout for JS and Python sandboxes (#6818)

Co-authored-by: Marcus <marcus@n8n.io>

packages/nodes-base/nodes/Code/Code.node.ts

@@ -92,8 +92,9 @@ export class Code implements INodeType {
 		const nodeMode = this.getNodeParameter('mode', 0) as CodeExecutionMode;
 		const workflowMode = this.getMode();
 
+		const node = this.getNode();
 		const language: CodeNodeEditorLanguage =
-			this.getNode()?.typeVersion === 2
+			node.typeVersion === 2
 				? (this.getNodeParameter('language', 0) as CodeNodeEditorLanguage)
 				: 'javaScript';
 		const codeParameterName = language === 'python' ? 'pythonCode' : 'jsCode';
@@ -107,16 +108,16 @@ export class Code implements INodeType {
 				context.item = context.$input.item;
 			}
 
-			if (language === 'python') {
+			const Sandbox = language === 'python' ? PythonSandbox : JavaScriptSandbox;
-				context.printOverwrite = workflowMode === 'manual' ? this.sendMessageToUI : null;
+			const sandbox = new Sandbox(context, code, index, this.helpers);
-				return new PythonSandbox(context, code, index, this.helpers);
+			sandbox.on(
-			} else {
+				'output',
-				const sandbox = new JavaScriptSandbox(context, code, index, workflowMode, this.helpers);
+				workflowMode === 'manual'
-				if (workflowMode === 'manual') {
+					? this.sendMessageToUI
-					sandbox.vm.on('console.log', this.sendMessageToUI);
+					: (...args) =>
-				}
+							console.log(`[Workflow "${this.getWorkflow().id}"][Node "${node.name}"]`, ...args),
-				return sandbox;
+			);
-			}
+			return sandbox;
 		};
 
 		// ----------------------------------

packages/nodes-base/nodes/Code/JavaScriptSandbox.ts

@@ -1,6 +1,5 @@
-import type { NodeVMOptions } from 'vm2';
 import { NodeVM, makeResolverFromLegacyOptions } from 'vm2';
-import type { IExecuteFunctions, INodeExecutionData, WorkflowExecuteMode } from 'n8n-workflow';
+import type { IExecuteFunctions, INodeExecutionData } from 'n8n-workflow';
 
 import { ValidationError } from './ValidationError';
 import { ExecutionError } from './ExecutionError';
@@ -20,23 +19,13 @@ export const vmResolver = makeResolverFromLegacyOptions({
 	builtin: builtIn?.split(',') ?? [],
 });
 
-const getSandboxOptions = (
-	context: SandboxContext,
-	workflowMode: WorkflowExecuteMode,
-): NodeVMOptions => ({
-	console: workflowMode === 'manual' ? 'redirect' : 'inherit',
-	sandbox: context,
-	require: vmResolver,
-});
-
 export class JavaScriptSandbox extends Sandbox {
-	readonly vm: NodeVM;
+	private readonly vm: NodeVM;
 
 	constructor(
 		context: SandboxContext,
 		private jsCode: string,
 		itemIndex: number | undefined,
-		workflowMode: WorkflowExecuteMode,
 		helpers: IExecuteFunctions['helpers'],
 	) {
 		super(
@@ -49,7 +38,13 @@ export class JavaScriptSandbox extends Sandbox {
 			itemIndex,
 			helpers,
 		);
-		this.vm = new NodeVM(getSandboxOptions(context, workflowMode));
+		this.vm = new NodeVM({
+			console: 'redirect',
+			sandbox: context,
+			require: vmResolver,
+		});
+
+		this.vm.on('console.log', (...args: unknown[]) => this.emit('output', ...args));
 	}
 
 	async runCodeAllItems(): Promise<INodeExecutionData[]> {

packages/nodes-base/nodes/Code/PythonSandbox.ts

@@ -67,10 +67,7 @@ export class PythonSandbox extends Sandbox {
 				globalsDict.set(key, value);
 			}
 
-			await pyodide.runPythonAsync(`
+			pyodide.setStdout({ batched: (str) => this.emit('output', str) });
-if 'printOverwrite' in globals():
-	print = printOverwrite
-			`);
 
 			const runCode = `
 async def __main():

packages/nodes-base/nodes/Code/Sandbox.ts

@@ -1,3 +1,4 @@
+import { EventEmitter } from 'events';
 import { ValidationError } from './ValidationError';
 import { isObject } from './utils';
 
@@ -31,12 +32,14 @@ export function getSandboxContext(this: IExecuteFunctions, index: number): Sandb
 	};
 }
 
-export abstract class Sandbox {
+export abstract class Sandbox extends EventEmitter {
 	constructor(
 		private textKeys: SandboxTextKeys,
 		protected itemIndex: number | undefined,
 		protected helpers: IExecuteFunctions['helpers'],
-	) {}
+	) {
+		super();
+	}
 
 	abstract runCodeAllItems(): Promise<INodeExecutionData[]>;
 

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

@@ -20,6 +20,7 @@ describe('Test Code Node', () => {
 describe('Code Node unit test', () => {
 	const node = new Code();
 	const thisArg = mock<IExecuteFunctions>({
+		getNode: () => mock(),
 		helpers: { normalizeItems },
 		prepareOutputData: NodeHelpers.prepareOutputData,
 	});