export function createLatchedDraftState(allowedKeys) {
  const allowed = new Set(allowedKeys);
  const modified = new Set();

  return Object.freeze({
    mark(key) {
      if (!allowed.has(key)) throw new Error(`Unknown draft field: ${key}`);
      const wasModified = modified.has(key);
      modified.add(key);
      return !wasModified;
    },
    clear() {
      modified.clear();
    },
    has(key) {
      return modified.has(key);
    },
    get dirty() {
      return modified.size > 0;
    },
    keys() {
      return [...modified];
    },
  });
}