InsaneHook

Enjoy the enforcing-DSL of this command-patterny gem.

Current version

0.4.0

Installation

Add this line to your application's Gemfile:

gem 'insane_hook'

And then execute:

$ bundle

Or install it yourself as:

$ gem install insane_hook

Usage

class YeOldeTaske < InsaneHook
  requires :some_required_arg
  fallbacks :some_optional_arg

  call do
    result "meaningful value"
  end
end

Is equivalent to:

class YeOldeTaske

  def self.call(**args)
    new(**args).call
  end

  attr_reader :some_required_arg, :some_optional_arg
  def initialize(some_required_arg:, some_optional_arg: nil)
    @some_required_arg = some_required_arg
    @some_optional_arg = some_optional_arg
  end

  def call
    result "meaningful value"
    self
  end

  def result(arg = InsaneHook::NO_ARG)
    if arg == InsaneHook::NO_ARG
      if instance_variable_defined?(:@result)
        @result
      else
        raise InsaneHook::CommandNotRunError
      end
    else
      @result = arg
    end
  end

end

Design decisions

1. Usage of call is idiomatic Ruby. Procs and method objects respond to call, so we are extending an existing Ruby pattern.
2. Commands should not return anything, but if you are forced to check a result, then set the result to a single object and work off of that object, for instance if you want to use the command as one of the clauses of a case statement (in which case the result would be a boolean)
3. Composition is usually better than Inheritance, especially in a language that doesn't support multiple inheritance. Here we need to use inheritance because we are completely taking over both the .new and the #initialize methods, meaning the object does not truly belong to the person writing the code.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec 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.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/trevoke/insane_hook.

License

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