Neco

Neco is a NEo COmmand pattern library for Ruby.

Add this line to your application's Gemfile:

gem 'neco'

And then execute:

$ bundle

Or install it yourself as:

$ gem install neco

Include Neco::Command module and define your command with DSLs like below:

class Foo
  include Neco::Command

  validates do |name:|
    name == 'Tama'
  end

  main do |name:|
    puts "Hello, #{name}!"
  end
end

Foo.call(name: 'Tama') # => 'Hello, Tama!'

Here, validates block defines validations and main block defines main logic for the command (simple, right?)

You can also compose multiple commands into one command using Neco::Composition module. Neco automatically triggers rollbacks when one of the commands raises an exception.

class Command1
  include Neco::Command

  main do
    set :cat_name, 'Tama'
  end

  rollback do
    puts 'Rolling back Command1!'
  end
end

class Command2
  include Neco::Command

  main do |cat_name:|
    puts "Hello, #{cat_name}!"
  end

  rollback do
    puts 'Rolling back Command2!'
  end
end

class Command3
  include Neco::Command

  # Unused block argument
  main do |cat_name:|
    raise 'OMG!!!'
  end
end

class Bar
  include Neco::Composition

  composes Command1, Command2, Command3
end

Bar.call
# => 'Hello, Tama!'
# => 'Rolling back Command2!'
# => 'Rolling back Command1!'

See examples directory for details.

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/okuramasafumi/neco. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

The gem is available as open source under the terms of the MIT License.

Everyone interacting in the Neco project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.