includes

Ensures the value of field under validation contains a given substring.

const rules = {
  url: 'includes:adonisjs.com'
}

// or
const rules = {
  url: [
    rule('includes', ['adonisjs.com'])
  ]
}

For customized build, you can import this rule as follows.

import { includes } from 'indicative/builds/validations'