src/helpers/clone-object.ts
/**
* Returns new object with values cloned from the original object. Some objects
* (like Sequelize or MongoDB model instances) contain circular references
* and cause TypeError when trying to JSON.stringify() them. They may contain
* custom toJSON() or toObject() method which allows to serialize them safely.
* Object.assign() does not clone these methods, so the purpose of this method
* is to use result of custom toJSON() or toObject() (if accessible)
* for Object.assign(), but only in case of serialization failure.
*
* @param obj - Object to clone
* @returns Cloned object
*/
export function cloneObject<T extends Record<string, unknown>> (
obj: T
): T {
if (typeof obj.toJSON === 'function' || typeof obj.toObject === 'function') {
try {
JSON.stringify(Object.assign({}, obj));
} catch (err) {
return (typeof obj.toJSON === 'function')
? obj.toJSON()
// @ts-expect-error does not know about toObject()
: obj.toObject();
}
}
return Object.assign({}, obj);
}