Custom Validator

Regexp

import jm from 'json-msg'

const schema = {
  username: jm.str({ hasNumber: /[0-9]/ }),
}

Function

• value is the value of the data that you passed in
• function must return a boolean

import jm from 'json-msg'

const schema = {
  username: jm.str({ hasNumber: (value) => /[0-9]/.test(value) }),
}