alpha

Validates the value to only have letters. The validation rule only works with the string schema type.

import { schema, rules } from '@ioc:Adonis/Core/Validator'

{
  username: schema.string([
    rules.alpha(),
  ])
}

You can also allow the string to have spaces, dash and underscore characters.

{
  username: schema.string([
    rules.alpha({
      allow: ['space', 'underscore', 'dash']
    })
  ])
}