react-state-form/src/utils/validationRules.js

const validations = {
  email : {
    rule    : () => /^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i,
    formatter (fieldName) {
      return `${fieldName} is not valid email`
    }
  },
  required : {
    rule    : () => /\S/,
    formatter (fieldName) {
      return `${fieldName} is required.`
    }
  },
  numeric : {
    rule : () => /^\d+$/,
    formatter (fieldName) {
      return `${fieldName} should contain only numbers.`
    }
  },
  alphaNumeric : {
    rule : () => /^[a-z0-9]+$/i,
    formatter (fieldName) {
      return `${fieldName} should not contain special characters, please use only alphabets and numbers.`
    }
  },
  alphabetic : {
    rule : () => /^[a-z]+$/i,
    formatter (fieldName) {
      return `${fieldName} should contain only alphabets.`
    }
  },
  maxLength : {
    rule : (number) => ({
      test : (value) => value.length <= number
    }),
    formatter (fieldName, number) {
      return number
        ? `${fieldName} can contain maximum ${number} characters.`
        : `${fieldName} contains more characters than expected.`
    }
  },
  minLength : {
    rule : (number) => ({
      test : (value) => value.length >= number
    }),
    formatter (fieldName, number) {
      return number
        ? `${fieldName} should contain minimum ${number} characters.`
        : `${fieldName} contains less characters than expected.`
    }
  }
}

export default validations