requiredIf

The field is checked for required validation, when expected field exists.

const rules = {
  address: 'required_if:needs_delivery'
}

// or
const rules = {
  address: [
    rule('required_if', 'needs_delivery')
  ]
}

For customized build, you can import this rule as follows.

import { requiredIf } from 'indicative/builds/validations'