deepFreeze.ts

/**
 * https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/freeze
 */
function deepFreeze<T>(object: T, path?: string): Readonly<T> {
  const propNames = Object.getOwnPropertyNames(object);
  let latest;
  try {
    for (const name of propNames) {
      // @ts-ignore - do not verify implementation
      const value = object[name];
      latest = name;
      // @ts-ignore - do not verify implementation
      object[name] = value && typeof value === "object" ? deepFreeze(value, path !== undefined ? `${path}/${latest}` : path) : value;
    }
  } catch (e) {
    // ignore if it was freezed before
    if (path) console.log(`Can't freeze ${path}/${latest}`);
  }
  return Object.freeze(object);
}