startsWith

Ensure the value of field under validation starts with a certain substr. This validation will also trim whitespaces before making the check

const rules = {
  phone_no: 'starts_with:99'
}

// or
const rules = {
  phone_no: [
    rule('starts_with', 99)
  ]
}

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

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