Joi：如何仅验证两个键之一（带数组）？

Question

Let's say I have user object with id number and roles array:

const user = {
  id: 1,
  roles: [ 'admin' ]
};

And validation of this object should pass if:

1. id is matching some external value
2. OR roles includes admin string

I've tried this approach but it doesn't work as expected:

const schema = Joi.object({
  id: Joi.number().valid(Joi.ref('$userId')), // shouldn't pass as $userId === 2
  roles: Joi.array().has(Joi.string().valid('admin')) // should pass as user has 'admin' role
}).or('id');

schema.validate(user, {
  context: {
    userId: 2
  }
}); // should pass as `user` includes `admin` in `roles` (but `userId` not equals `user.id`)

Answer 1

I found an answer, this scenario can be accomplished using when operation:

Joi.object({
  id: Joi.number(),
  roles: Joi.array().when('id', { 
    not: Joi.ref('$userId'), 
    then: Joi.array().has(Joi.string().valid('admin'))
  })
});