@nestia/sdk/src/utils/MapUtil.ts

Nestia SDK and Swagger generator

export namespace MapUtil {
  export function take<Key, T>(
    dict: Map<Key, T>,
    key: Key,
    generator: () => T,
  ): T {
    const oldbie: T | undefined = dict.get(key);
    if (oldbie) return oldbie;

    const value: T = generator();
    dict.set(key, value);
    return value;
  }
}