From 8126181e180ef6a505b46eab3942a5899c8c5116 Mon Sep 17 00:00:00 2001
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 <netroy@users.noreply.github.com>
Date: Mon, 7 Aug 2023 11:52:33 +0200
Subject: [PATCH] fix(editor): Avoid infinite loops when resolving the
 expression `{{ $parameter }}` (no-changelog) (#6855)

Co-authored-by: Oleg Ivaniv <me@olegivaniv.com>
---
 cypress/e2e/11-inline-expression-editor.cy.ts    | 4 ++--
 packages/editor-ui/src/mixins/workflowHelpers.ts | 9 ++++++---
 packages/workflow/src/WorkflowDataProxy.ts       | 6 ++++++
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/cypress/e2e/11-inline-expression-editor.cy.ts b/cypress/e2e/11-inline-expression-editor.cy.ts
index e1fbb08f36..f7e192e06c 100644
--- a/cypress/e2e/11-inline-expression-editor.cy.ts
+++ b/cypress/e2e/11-inline-expression-editor.cy.ts
@@ -51,7 +51,7 @@ describe('Inline expression editor', () => {
 	it('should resolve array resolvables', () => {
 		WorkflowPage.getters.inlineExpressionEditorInput().clear();
 		WorkflowPage.getters.inlineExpressionEditorInput().type('{{');
-		WorkflowPage.getters.inlineExpressionEditorInput().type('[1, 2, 3]', { timeout: 20000 });
+		WorkflowPage.getters.inlineExpressionEditorInput().type('[1, 2, 3]');
 		WorkflowPage.getters.inlineExpressionEditorOutput().contains(/^\[Array: \[1,2,3\]\]$/);
 
 		WorkflowPage.getters.inlineExpressionEditorInput().clear();
@@ -66,7 +66,7 @@ describe('Inline expression editor', () => {
 		WorkflowPage.getters.inlineExpressionEditorInput().clear();
 		WorkflowPage.getters.inlineExpressionEditorInput().type('{{');
 		// Resolving $parameter is slow, especially on CI runner
-		WorkflowPage.getters.inlineExpressionEditorInput().type('$parameter["operation"]', { timeout: 35000 });
+		WorkflowPage.getters.inlineExpressionEditorInput().type('$parameter["operation"]');
 		WorkflowPage.getters.inlineExpressionEditorOutput().contains(/^get$/);
 	});
 });
diff --git a/packages/editor-ui/src/mixins/workflowHelpers.ts b/packages/editor-ui/src/mixins/workflowHelpers.ts
index 33867f0785..04ea11bc07 100644
--- a/packages/editor-ui/src/mixins/workflowHelpers.ts
+++ b/packages/editor-ui/src/mixins/workflowHelpers.ts
@@ -657,11 +657,14 @@ export const workflowHelpers = defineComponent({
 				return null;
 			}
 
-			if (typeof returnData['__xxxxxxx__'] === 'object') {
+			const obj = returnData['__xxxxxxx__'];
+			if (typeof obj === 'object') {
+				const proxy = obj as { isProxy: boolean; toJSON?: () => unknown } | null;
+				if (proxy?.isProxy && proxy.toJSON) return JSON.stringify(proxy.toJSON());
 				const workflow = getCurrentWorkflow();
-				return workflow.expression.convertObjectValueToString(returnData['__xxxxxxx__'] as object);
+				return workflow.expression.convertObjectValueToString(obj as object);
 			}
-			return returnData['__xxxxxxx__'];
+			return obj;
 		},
 
 		async updateWorkflow(
diff --git a/packages/workflow/src/WorkflowDataProxy.ts b/packages/workflow/src/WorkflowDataProxy.ts
index 2a044cfc91..a9d5002e26 100644
--- a/packages/workflow/src/WorkflowDataProxy.ts
+++ b/packages/workflow/src/WorkflowDataProxy.ts
@@ -27,6 +27,7 @@ import * as NodeHelpers from './NodeHelpers';
 import { ExpressionError } from './ExpressionError';
 import type { Workflow } from './Workflow';
 import { augmentArray, augmentObject } from './AugmentObject';
+import { deepCopy } from './utils';
 
 export function isResourceLocatorValue(value: unknown): value is INodeParameterResourceLocator {
 	return Boolean(
@@ -213,6 +214,8 @@ export class WorkflowDataProxy {
 			},
 			get(target, name, receiver) {
 				if (name === 'isProxy') return true;
+				if (name === 'toJSON') return () => deepCopy(target);
+
 				name = name.toString();
 
 				let returnValue: NodeParameterValueType;
@@ -231,6 +234,9 @@ export class WorkflowDataProxy {
 					returnValue = node.parameters[name];
 				}
 
+				// Avoid recursion
+				if (returnValue === `={{ $parameter.${name} }}`) return undefined;
+
 				if (isResourceLocatorValue(returnValue)) {
 					if (returnValue.__regex && typeof returnValue.value === 'string') {
 						const expr = new RegExp(returnValue.__regex);