Component initializers

componentizer.rb

class Component
  attr_writer :post

  def initialize(session:, fun: "bags", deeze:)
    @session = session
    @fun     = fun  # Make sure we assign this, otherwise @fun would be nil
    @deeze   = deeze
  end
end

# Some globals (simulating a Rails controller context, etc.)
@post = "This is wonderful!"
@session = {}
@deeze = "🥜!"

def extract_initialize_values(klass, initializer: :initialize)
  klass
    .instance_method(initializer)
    .parameters
    .each_with_object Hash.new do |param, hash|
      case param
      in :keyreq, name
        hash[name] = instance_variable_get("@#{name}") if instance_variable_defined?("@#{name}")
      in :key, name
        hash[name] = instance_variable_get("@#{name}") if instance_variable_defined?("@#{name}")
      else
        puts "No match for #{param}"
        next
      end
    end
end

def assign_attr_writers(instance)
  instance.tap do |instance|
    instance.instance_variables.each do |variable|
      attr_writer_name = "#{variable[1..-1]}="
      if instance.respond_to?(attr_writer_name)
        instance.send(
          attr_writer_name,
          instance.instance_variable_get(variable)
        )
      end
    end
  end
end

def initialize_keyword_arguments(klass)
  klass.new **extract_initialize_values(klass)
end

def component(klass)
  assign_attr_writers initialize_keyword_arguments Component
end