Medium 702687394e3d-railway-oriented-programming

medium-702687394e3d-railway-oriented-programming.rb

module Posts
  class Create
    include Dry::Monads[:result, :do]
    
    ValidationSchema = Dry::Schema.Params do
      required(:title).filled(:str?)
      optional(:body).maybe(:str?)
    end

    def self.call(params)
      new.execute(params)
    end

    private

    def execute(params)
      yield validate_params(params)
      create_post(params)
    end

    def validate_params(params)
      validation_outcome = ValidationSchema.call(params)

      return Failure(validation_outcome.errors.to_h) if validation_outcome.failure?

      Success()
    end

    def create_post(params)
      post = Post.create(params)
      Success(post)
    end
  end
end