Initialize objects with default values

application.rb

require 'pry'
require 'pry-nav'

class Application
  def self.call(*args, &)
    new(*args, &).call
  end

  private

  def response(success: false, payload: {}, error: nil)
    Struct.new('Response', :success?, :payload, :error) unless Struct::const_defined?('Response')
    Struct::Response.new(success, payload, error)
  end
end

article.rb

# quickstart
#
# ruby article.rb

require_relative 'application.rb'

require 'pry'
require 'pry-nav'

class Article < Application
  attr_accessor :params

  def initialize(name = '')
    @name = name
    yield(self) if block_given?
    return if params.nil?

    @attr_0 = params[:attr_0]
    @attr_1 = params[:attr_1]
  end

  def call
    puts "name: #{name}"
    puts "params: #{params}"
    puts "attr_0: #{attr_0}"
    puts "attr_1: #{attr_1}"
    response(success: true, payload: { name:, attr_0:, attr_1: })
  end

  private

  attr_reader :name, :attr_0, :attr_1
end

obj = Article.call('Joa') do |a|
  a.params = {
    attr_0: 'attr_0',
    attr_1: 'attr_1'
  }
end

puts obj.success?
puts obj.payload

output.txt

name: Joa
params: {:attr_0=>"attr_0", :attr_1=>"attr_1"}
attr_0: attr_0
attr_1: attr_1
true
{:name=>"Joa", :attr_0=>"attr_0", :attr_1=>"attr_1"}