safe-stringify/index.js

Serialize objects to JSON with handling for circular references

function safeStringifyReplacer(seen) {
	const replacer = function (key, value) {
		// Handle objects with a custom `.toJSON()` method.
		if (typeof value?.toJSON === 'function') {
			value = value.toJSON();
		}

		if (!(value !== null && typeof value === 'object')) {
			return value;
		}

		if (seen.has(value)) {
			return '[Circular]';
		}

		seen.add(value);

		const newValue = Array.isArray(value) ? [] : {};

		for (const [key2, value2] of Object.entries(value)) {
			newValue[key2] = replacer(key2, value2);
		}

		seen.delete(value);

		return newValue;
	};

	return replacer;
}

export default function safeStringify(object, {indentation} = {}) {
	const seen = new WeakSet();
	return JSON.stringify(object, safeStringifyReplacer(seen), indentation);
}