Require only one of 4 fields

validationSchema={
  Yup.object().shape({
    emailAddress: Yup.string().email('Please enter a valid email address'),
    phoneHome: Yup.number().typeError('Home Phone must be a number'),
    phoneMobile: Yup.number().typeError('Mobile Phone must be a number'),
    phoneWork: Yup.number().typeError('Work Phone must be a number'),
  })
  .test(
    'at-least-one-contact',
    'You must provide at least one contact method',
    value => {
      const test = !!(value.emailAddress || value.phoneHome || value.phoneMobile || value.phoneWork);
      return Yup.ValidationError(['emailAddress', 'phoneHome', 'phoneMobile', 'phoneWork'], 'one is required', '');
    }
  )
}

Basically I am getting an error on the value => { definition saying

Type 'ValidationError' is not assignable to type 'boolean | Promise<boolean>'.

Is there an easy way to do this so only one field is required?

[risenforces]

I use this:

const Yup = require('yup')

Yup.addMethod(Yup.object, 'atLeastOneOf', function(list) {
  return this.test({
    name: 'atLeastOneOf',
    message: '${path} must have at least one of these keys: ${keys}',
    exclusive: true,
    params: { keys: list.join(', ') },
    test: value => value == null || list.some(f => value[f] != null)
  })
})

const Schema = Yup.object()
  .shape({
    one: Yup.number(),
    two: Yup.number(),
    three: Yup.number()
  })
  .atLeastOneOf(['one', 'two'])

Schema.isValidSync({ three: 3 }) // false
Schema.isValidSync({ one: 1, three: 3 }) // true

[NathanHealea]

@calmattack,

I had a similar situation and solved it with the following code.

My solution requires selecting other input elements and checking the value. With more time you could probable adept @risenforces solution to pass in the schema for validation instead of selecting elements.

yup.addMethod(yup.string, 'requiredIf', function(list, message) {
  return this.test('requiredIf', message, function(value) {
    const { path, createError } = this;

    // check if any in list contain value
    // true : one or more are contains a value
    // false: none contain a value
    var anyHasValue = list.some(value => {

      // return `true` if value is not empty, return `false` if value is empty
      return Boolean(document.querySelector(`input[name="${value}"]`).value);
    
    });

    // returns `CreateError` current value is empty and no value is found, returns `false` if current value is not empty and one other field is not empty.
    return !value && !anyHasValue
      ? createError({ path, message })
      : true;
  });
});


const schema = yup.object().shape({
  email: yup.string().requiredIf(['work','home','cell']),
  work: yup.string().requiredIf(['email','home','cell']),
  home: yup.string().requiredIf(['email','work','cell']),
  cell: yup.string().requiredIf(['email','work','home']),
});