Conditional validation with Yup and Formik

Question

Here is my validation schema:

const validationSchema = Yup.object().shape({
      person: Yup.object().shape({
        name: Yup.string().required('Field is required'),
        surname: Yup.string().required('Field is required'),
        middleName: Yup.string().required('Field is required'),
        email: Yup.string()
          .email('Wrong e-mail format')
          .required('Field is required')
      }),
      company: Yup.object().shape({
        name: Yup.string().required('Field is required'),
        address: Yup.string().required('Field is required'),
        email: Yup.string()
          .email('Wrong e-mail format')
          .required('Field is required')
      })
    });

And also there are two variables in React State: isPerson and isCompany. How to make validation work conditionally, for example if isPerson is true, then person in validationSchema is required to be validated?

Answer 1

Updated ans: 2020.

you can use Yup conditions

const validationSchema = Yup.object().shape({

      isCompany: Yup.boolean(),
      companyName: Yup.string().when('isCompany', {
        is: true,
        then: Yup.string().required('Field is required')
      }),
      companyAddress: Yup.string().when('isCompany', {
        is: (isCompany) => true,//just an e.g. you can return a function
        then: Yup.string().required('Field is required'),
        otherwise: Yup.string()
      }),
    });

And make sure to update your form accordingly. I hope you get the point...