Conditional validation with joi

0
votes

I try to implement conditional validation with Joi. I have an endpoint that can accept either:

{
  from: 'abc'
}

or

{
  type: 'some-type'
}

If the type field isn't present, the from field is mandatory and if the from field isn't present, the type field is mandatory. The type can only accept a set of value.

I tried the following approach without success:

type: joi.alternatives().conditional('from', { is: joi.string().empty(), then: joi.string().required().valid('val1', 'val2'), otherwise: joi.optional() })
  .messages({
    'any.valid': 'type.not.supported.value',
    'any.required': 'type.required'
  }),
from: joi.alternatives().conditional('type', { is: joi.string().empty(), then: joi.required(), otherwise: joi.optional() })
  .messages({
    'any.valid': 'from.not.supported.value',
    'any.required': 'from.required'
  })

Thanks for your help! Thierry

1
joi

1 Answers

1
votes

What you describe sounds like an or constraint.

...a relationship between keys where one of the peers is required (and more than one is allowed)

The following schema would work:

joi.object().keys({
  type: joi.string().valid('val1', 'val2'),
  from: joi.string()
}).or('type', 'from');