CODEWITHSUNDEEP
javascriptjoi
Ana María Arrufat Sánchez
Ana María Arrufat Sánchez

Reputation: 13

Joi: validate array element depending on index

In Joi is there any way to validate elements of an array based on its index? I have this:

const schema = Joi.array().items(
      Joi.object({
        a: Joi.string(),
        b: Joi.number()
      })
    )

and i want "a" required only for first element.

Upvotes: 1

Views: 1712

Answers (1)

soltex
soltex

Reputation: 3531

Yes, there is a way. You can combine array.ordered with array.items:

const schema = Joi.array()
    .ordered(Joi.object({
        a: Joi.string().required(),
        b: Joi.number()
    }))
    .items(Joi.object({
        a: Joi.string(),
        b: Joi.number()
    }));

This way, the array must have the first item as the object you defined with a required, and the subsequent items wouldn't have the a required.

This validation will pass:

schema.validate([{ a: '123', b: 10 }, { a: '123', b: 10 }])

And this one will fail:

// ValidationError: "[0].a" is required
schema.validate([{ b: 10 }, { a: '123', b: 10 }])

It could be a little bit tricky if you want to validate some other element than the first one.

Upvotes: 1

Related Questions