Yup conditional object validation not working

Question

I'm trying to define a Yup validation for an object - if a defined sibling is set to true, the field of type object should be required, otherwise not

Example:

const { object, string, number, date, boolean } = require('yup')

const contactSchema = object({
  isBig: boolean(),
  count: number()
    .when('isBig', {
      is: true, // alternatively: (val) => val == true
      then: number().min(5),
      otherwise: number().min(0),
    }),
 complexOne: object({
    simpleOne: string(),
 })
 .when('isBig', {
     is: true,
     then: object().required(),
     otherwise: object(),
 })
})

The object passed into the validation:

{
    isBig: true,
    count: -1,
}

As you can see, I intentionally don't pass the complexOne since I want Yup to display the error. The validation for the count works correctly - if the value is less than 0 and the isBig is set to true, Yup will correctly display an error message ValidationError: count must be greater than or equal to 5

Unfortunately, it completely ignores the conditional validation set for the complexOne field. Either yup does not support the when for object types or I'm doing something incorrectly.

Thanks for any help

Fraction Fraction · Accepted Answer · 2020-04-16T20:43:46

you must set strict option to true in order to only validate the object, and skip any coercion or transformation:

contactSchema.validate(contact, { strict: true })
.then(obj => {
  console.log(obj)
}, err => {
  console.log(err.message)
})

Demo:

Yup conditional object validation not working

1 Answers