

Extensions

Monads

The monads extension makes Dry::Validation::Result objects compatible with dry-monads.

To enable the extension:

require 'dry/validation'

Dry::Validation.load_extensions(:monads)

After loading the extension, you can leverage monad API:

class MyContract < Dry::Validation::Contract
  params do
    required(:name).filled(:string)
  end
end

my_contract = MyContract.new

my_contract.(name: "")
  .to_monad
  .fmap { |r| puts "passed: #{r.to_h.inspect}" }
  .or   { |r| puts "failed: #{r.errors.to_h.inspect}" }