dry_validation_with_types.rb

# dry-validation (0.10.7)
# dry-types (0.10.3)

require 'dry/types'
require 'dry/validation'

module Types
  include Dry::Types.module
  Phone = String.constrained(format: /\A([\d]{10}|)\z/)
end

Create = Dry::Validation.JSON do
  optional(:phone, Types::Phone).filled
end

p Create.(phone: '123')
# => #<Dry::Validation::Result output={:phone=>"123"} errors={}>
p Create.(phone: 'test phone with invalod chars 12324')
# => #<Dry::Validation::Result output={:phone=>"test phone with invalod chars 12324"} errors={}>