Yup validation of comma delimited string

yup-schema.js

const schema = yup.object({
  id: yup
    .array()
    .transform((value, originalValue, context) => {
      if (context.isType(value) && value !== null) {
        return value;
      }

      return originalValue ? String(originalValue).split(/[\s,]+/) : [];
    })
    .of(yup.string())
    .min(1)
    .required(),
});

// Tests
schema.validate({}); // fails
schema.validate({ id: '' }); // fails
schema.validate({ id: '123' }); // passes
schema.validate({ id: '123,321' }); // passes

// Returns
schema.validate({ id: '123,321' }); // ['123','321']

Source/inspiration - jquense/yup#564 (comment)