Just doesn't show the name of the field causing the error

I wrote my first test using Frisby and I got a strange behaviour.

This is a portion of my test file:

it('check function', function (done) {
  frisby.get(BASE_URL + 'check')
    .expect('status', 200)
    .done(done);
});

it('user login', function (done) {
  frisby.post(BASE_URL + 'login', user)
    .expect('status', 200)
    .expect('jsonTypes', 'id', Joi.number().required())
    .expect('jsonTypes','email', Joi.string().email().required())
    .expect('json','emailConfirmed', 1)
    .expect('jsonTypes','nome', Joi.string().required())
    .expect('jsonTypes','cognome', Joi.string().required())
    .expect('jsonTypes','avatar', Joi.string()) 
    .expect('jsonTypes','citta', Joi.string().required())   
    .expect('jsonTypes','token', Joi.string().required())
    .expect('json','role', 'user')
    .done(done);
});

and it works fine!

If I change this row

.expect('jsonTypes','name', Joi.string().required())

with the following one

.expect('jsonTypes','name', Joi.number().required())

I got this output

● user login

    ValidationError: "value" must be a number

      at Object.<anonymous>.exports.process (node_modules/joi/lib/errors.js:152:19)
      at Object.<anonymous>.internals.Number.Object.<anonymous>.internals.Any._validateWithOptions (node_modules/joi/lib/any.js:633:27)
      at Object.<anonymous>.module.exports.internals.Any.root.validate (node_modules/joi/lib/index.js:104:23)
      at jsonTypesAssertion (node_modules/frisby/src/frisby/expects.js:104:24)
      at Object.withPath (node_modules/frisby/src/frisby/utils.js:67:12)
      at FrisbySpec.jsonTypes (node_modules/frisby/src/frisby/expects.js:103:11)
      at FrisbySpec._addExpect.response (node_modules/frisby/src/frisby/spec.js:368:23)
      at FrisbySpec._runExpects (node_modules/frisby/src/frisby/spec.js:260:24)
      at _fetch.fetch.then.then.responseBody (node_modules/frisby/src/frisby/spec.js:139:14)
      at process._tickCallback (internal/process/next_tick.js:109:7)

I should expect to receive

"name" must be a number

in order to immediately identify the error in my API.

Moreover, if I change my API removing the field "name", I got this output

  ● user login

    ValidationError: "value" is required

It seems that Jest shows the Joi output, and Joi doesn't know the field name. But jest does, so it should show the proper name of the field causing the error.

Am I missing something?