This example demonstrates how to create Ruby Structs that use newer hash-style parameters, and are able to have default values for some of the properties. Raw

struct_optional_arguments.rb

# This example demonstrates how to create Ruby Structs that use
# newer hash-style parameters, as well as the default values for
# some of the parameters, without loosing the benefits of struct's
# implementation of #eql? #hash, #to_s, #inspect, and other
# useful instance methods.
#
# Run this file as follows
#
# > gem install rspec
# > rspec struct_optional_arguments.rb --format documentation
#
class StructWithOptionals < Struct.new(
	:encrypted_data,
	:cipher_name,
	:iv,
	:salt,
	:version
	)

	VERSION = '1.0.1'

	def initialize(
		encrypted_data:,
		cipher_name:,
		iv: nil,
		salt: 'salty',
		version: VERSION
		)
		super(encrypted_data, cipher_name, iv, salt, version)
	end
end

require 'rspec'
RSpec.describe StructWithOptionals do
	let(:struct) { StructWithOptionals.new(encrypted_data: 'data', cipher_name: 'AES-256-CBC', iv: 'intravenous') }

	it 'should be initialized with default values' do
		expect(struct.version).to be(StructWithOptionals::VERSION)
	end

	context 'all fields must be not null' do
		%i(encrypted_data cipher_name salt iv version).each do |field|
			subject { struct.send(field) }
			it field do
				expect(subject).to_not be_nil
			end
		end
	end
end