Function _resolveSetOption

src/purify.ts:190–206

(
  cfg: Config,
  key: keyof Config,
  fallback: Record<string, boolean>,
  options: {
    transform: Parameters<typeof addToSet>[2];
    base?: Record<string, boolean>;
  }
)

 * @returns the resolved set
 */
const _resolveSetOption = function (
  cfg: Config,
  key: keyof Config,
  fallback: Record<string, boolean>,
  options: {
    transform: Parameters<typeof addToSet>[2];
    base?: Record<string, boolean>;
  }
): Record<string, boolean> {
  return objectHasOwnProperty(cfg, key) && arrayIsArray(cfg[key])
    ? addToSet(
        options.base ? clone(options.base) : {},
        cfg[key] as readonly unknown[],
        options.transform
      )
    : fallback;
};

/**
 * Resolve an object-valued configuration option: a prototype-free clone