CODEWITHSUNDEEP
node.jstypescriptjoi
Alexander Zeitler
Alexander Zeitler

Reputation: 13119

Joi validate union type

I have union type PaymentTerm:

type PaymentTerm =
    | { type: 'AdvancePayment' }
    | { type: 'PaymentGoal'; netPaymentDays: number }

I want to validate it using Joi.alternatives:

  Joi.object({
    type: Joi.string().required().valid('AdvancePayment')
  }),
  Joi.object({
    type: Joi.string().required().valid('PaymentGoal'),
    netPaymentDays: Joi.number().required().messages({
      'any.required': '{{#label}} is required'
    })
  })
)

const { error, value } = schema.validate({
  type: 'PaymentGoal'
})

Now I would expect to get "netPaymentDays" is required but I get "value" does not match any of the allowed types.

How can I get the "nested" errors instead of the generic ones for the alternatives?

Upvotes: 2

Views: 2075

Answers (1)

Ankh
Ankh

Reputation: 5738

You've mentioned the correct way to resolve this but I can't see it being used in your example.

I want to validate it using Joi.alternatives

A possible solution for your schema would be:

Joi.object().keys({
    type: Joi.string().valid('AdvancePayment', 'PaymentGoal').required(),
    netPaymentDays: Joi.alternatives().conditional('type', {
        is: 'PaymentGoal',
        then: Joi.number().required(),
        otherwise: Joi.forbidden()
    })
});

Upvotes: 3

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