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']
})
])
}