transaction_validation.rb

# frozen_string_literal: true

Dry::Validation.load_extensions(:monads)

module BaseTransaction
  def self.included(base)
     base.include Dry::Transaction
     base.extend ClassMethods
  end

  module ClassMethods
    attr_reader :_contract

    def schema(&block)
      klass = Class.new(Dry::Validation::Contract) do
        schema(&block)
      end
      @_contract = klass.new
    end
  end

  def call_validated(input)
    self.class._contract
      .call(input)
      .to_monad
      .bind { call }
  end
end

class TestClass
  include BaseTransaction

   schema do
     required(:field).filled(:str?)
     required(:another_field).filled(:int?)
   end

  step :first_step
  tee :second_step

  private

  def first_step(input)
    Success(input)
  end

  def second_step(input)
    nil
  end
end

a = TestClass.new
a.call_validated(field: 1, another_field: 'test')
# => Failure(#<Dry::Validation::Result{:field=>1, :another_field=>"test"} errors={:field=>["must be a string"], :another_field=>["must be an integer"]}>)
a.call_validated(field: 'test', another_field: 1)
# => Success(nil)