yupSample1.js

const schema = yup.object().shape({
  users: yup.array(
    yup.object().shape({
      name: yup.string().required('name is required.'),
      email: yup
        .string()
        .required('email is required.')
        .email('invalid email type.')
        .test('email-dup', 'duplicated email', () => { /* バリデーションロジック */ }) // 新しく追加
    }),
  ),
});