fix(core): Remove circular refs from Code and push msg (#5741)

* remove circular refs from code items (and lint fixes)

* cleanup

---------

* add some tests

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

packages/workflow/src/utils.ts

@@ -62,6 +62,31 @@ export const jsonParse = <T>(jsonString: string, options?: JSONParseOptions<T>):
 	}
 };
 
+type JSONStringifyOptions = {
+	replaceCircularRefs?: boolean;
+	circularRefReplacement?: string;
+};
+
+const getReplaceCircularReferencesFn = (options: JSONStringifyOptions) => {
+	const knownObjects = new WeakSet();
+	return (key: any, value: any) => {
+		if (typeof value === 'object' && value !== null) {
+			if (knownObjects.has(value)) {
+				return options?.circularRefReplacement ?? '[Circular Reference]';
+			}
+			knownObjects.add(value);
+		}
+		return value;
+	};
+};
+
+export const jsonStringify = (obj: unknown, options: JSONStringifyOptions = {}): string => {
+	const replacer = options?.replaceCircularRefs
+		? getReplaceCircularReferencesFn(options)
+		: undefined;
+	return JSON.stringify(obj, replacer);
+};
+
 export const sleep = async (ms: number): Promise<void> =>
 	new Promise((resolve) => {
 		setTimeout(resolve, ms);