//////////////////////
type OriginalType = {
    key1: { sub1: string; sub2: string };
    key2: { subA: string; subB: string };
  };
  
  type ValidKeys = keyof OriginalType;
  type ValidSubKeys<K extends ValidKeys> = keyof OriginalType[K];
  
  type EnforcedRecord = {
    [K in ValidKeys]: ValidSubKeys<K>[];
  };
  
  // Example usage:
  const example: EnforcedRecord = {
    key1: ['sub1', 'sub2'],
    key2: ['subA', 'subB', "sub1"], // last is invalid
  };