fix: Show error when referencing node that exist but has not been executed (#6496)

Co-authored-by: कारतोफ्फेलस्क्रिप्ट™ <aditya@netroy.in>

packages/workflow/test/WorkflowDataProxy.test.ts

@@ -2,6 +2,7 @@ import type { IConnections, IExecuteData, INode, IRunExecutionData } from '@/Int
 import { Workflow } from '@/Workflow';
 import { WorkflowDataProxy } from '@/WorkflowDataProxy';
 import * as Helpers from './Helpers';
+import { ExpressionError } from '@/ExpressionError';
 
 describe('WorkflowDataProxy', () => {
 	describe('test data proxy', () => {
@@ -37,13 +38,21 @@ describe('WorkflowDataProxy', () => {
 				position: [460, 200],
 			},
 			{
-				name: 'End',
+				name: 'Set',
 				type: 'test.set',
 				parameters: {},
 				typeVersion: 1,
 				id: 'uuid-4',
 				position: [640, 200],
 			},
+			{
+				name: 'End',
+				type: 'test.set',
+				parameters: {},
+				typeVersion: 1,
+				id: 'uuid-5',
+				position: [640, 200],
+			},
 		];
 
 		const connections: IConnections = {
@@ -282,6 +291,14 @@ describe('WorkflowDataProxy', () => {
 			expect(proxy.$('Rename').params).toEqual({ value1: 'data', value2: 'initialName' });
 		});
 
+		test('$("NodeName")', () => {
+			expect(() => proxy.$('doNotExist')).toThrowError(ExpressionError);
+		});
+
+		test('$("NodeName")', () => {
+			expect(() => proxy.$('Set')).toThrowError(ExpressionError);
+		});
+
 		test('test $input.all()', () => {
 			expect(proxy.$input.all()[1].json.data).toEqual(160);
 		});