fix(core): Prevent proxy layer accumulation in ObservableObject (#30129)

packages/@n8n/task-runner/src/js-task-runner/js-task-runner.ts

@@ -2,13 +2,7 @@ import isObject from 'lodash/isObject';
 import set from 'lodash/set';
 import { DateTime, Duration, Interval } from 'luxon';
 import { getAdditionalKeys } from 'n8n-core';
-import {
-	WorkflowDataProxy,
-	Workflow,
-	ObservableObject,
-	Expression,
-	jsonStringify,
-} from 'n8n-workflow';
+import { WorkflowDataProxy, Workflow, Expression, jsonStringify } from 'n8n-workflow';
 import type {
 	CodeExecutionMode,
 	IWorkflowExecuteAdditionalData,
@@ -252,8 +246,6 @@ export class JsTaskRunner extends TaskRunner {
 			nodeTypes: this.nodeTypes,
 		});
 
-		workflow.staticData = ObservableObject.create(workflow.staticData);
-
 		const result =
 			settings.nodeMode === 'runOnceForAllItems'
 				? await this.runForAllItems(taskId, settings, data, workflow, abortSignal)

packages/workflow/src/observable-object.ts

@@ -19,6 +19,7 @@ export function create(
 
 	for (const key in target) {
 		if (typeof target[key] === 'object' && target[key] !== null) {
+			if ('__dataChanged' in (target[key] as object)) continue;
 			target[key] = create(
 				target[key] as IDataObject,
 				// eslint-disable-next-line @typescript-eslint/prefer-nullish-coalescing

packages/workflow/test/observable-object.test.ts

@@ -154,6 +154,20 @@ describe('ObservableObject', () => {
 		expect((testObject.a! as IDataObject).b).toEqual({ c: 2 });
 	});
 
+	test('should not stack overflow when create is called repeatedly on the same object', () => {
+		const source = { a: { b: { c: 1 } } };
+
+		for (let i = 0; i < 10_000; i++) {
+			ObservableObject.create(source);
+		}
+
+		const observable = ObservableObject.create(source);
+		expect(observable.__dataChanged).toBeFalsy();
+		((observable.a! as IDataObject).b! as IDataObject).c = 2;
+		expect(observable.__dataChanged).toBeTruthy();
+		expect(((observable.a! as IDataObject).b! as IDataObject).c).toEqual(2);
+	});
+
 	// test('xxxxxx', () => {
 	// 	const testObject = ObservableObject.create({ a: { } }, undefined, { ignoreEmptyOnFirstChild: true });
 	// 	expect(testObject.__dataChanged).toBeFalsy();