From 872535a40c85dcfad3a4b27c57c026ae003f562f Mon Sep 17 00:00:00 2001
From: Tomi Turtiainen <10324676+tomi@users.noreply.github.com>
Date: Wed, 4 Dec 2024 14:32:28 +0200
Subject: [PATCH] fix(core): Opt-out from optimizations if `$item` is used
 (#12036)

---
 .../built-ins-parser/__tests__/built-ins-parser.test.ts  | 9 ++++++++-
 .../js-task-runner/built-ins-parser/built-ins-parser.ts  | 5 +++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/packages/@n8n/task-runner/src/js-task-runner/built-ins-parser/__tests__/built-ins-parser.test.ts b/packages/@n8n/task-runner/src/js-task-runner/built-ins-parser/__tests__/built-ins-parser.test.ts
index 58d314dc19..dd866fc381 100644
--- a/packages/@n8n/task-runner/src/js-task-runner/built-ins-parser/__tests__/built-ins-parser.test.ts
+++ b/packages/@n8n/task-runner/src/js-task-runner/built-ins-parser/__tests__/built-ins-parser.test.ts
@@ -17,7 +17,7 @@ describe('BuiltInsParser', () => {
 	const parseAndExpectOk = (code: string) => {
 		const result = parser.parseUsedBuiltIns(code);
 		if (!result.ok) {
-			fail(result.error);
+			throw result.error;
 		}
 
 		return result.result;
@@ -151,6 +151,13 @@ describe('BuiltInsParser', () => {
 		});
 	});
 
+	describe('$item', () => {
+		it('should require all nodes and input when $item is used', () => {
+			const state = parseAndExpectOk('$item("0").$node["my node"].json["title"]');
+			expect(state).toEqual(new BuiltInsParserState({ needsAllNodes: true, needs$input: true }));
+		});
+	});
+
 	describe('ECMAScript syntax', () => {
 		describe('ES2020', () => {
 			it('should parse optional chaining', () => {
diff --git a/packages/@n8n/task-runner/src/js-task-runner/built-ins-parser/built-ins-parser.ts b/packages/@n8n/task-runner/src/js-task-runner/built-ins-parser/built-ins-parser.ts
index 9b9e4b34b2..7a5c7baf46 100644
--- a/packages/@n8n/task-runner/src/js-task-runner/built-ins-parser/built-ins-parser.ts
+++ b/packages/@n8n/task-runner/src/js-task-runner/built-ins-parser/built-ins-parser.ts
@@ -125,6 +125,11 @@ export class BuiltInsParser {
 	private visitIdentifier = (node: Identifier, state: BuiltInsParserState) => {
 		if (node.name === '$env') {
 			state.markEnvAsNeeded();
+		} else if (node.name === '$item') {
+			// $item is legacy syntax that is basically an alias for WorkflowDataProxy
+			// and allows accessing any data. We need to support it for backwards
+			// compatibility, but we're not gonna implement any optimizations
+			state.markNeedsAllNodes();
 		} else if (
 			node.name === '$input' ||
 			node.name === '$json' ||