Overrider

This gem adds override syntax that is similar to Java's one. override syntax ensures that a modified method has super method.

Unless the method has super method, this gem raise Overrider::NoSuperMethodError.

This gem is pseudo static code analyzer by TracePoint and Ripper.

it detect abstract violation when class(module) is defined, not runtime.

My similar gems

• finalist (final implementation)
• abstriker (abstract implementation)

Installation

Add this line to your application's Gemfile:

gem 'overrider'

And then execute:

$ bundle

Or install it yourself as:

$ gem install overrider

Usage

class A1
  def foo
  end
end

class A2 < A1
  extend Overrider

  override def foo
  end
end

this is OK.

class B1
end

class B2 < B1
  extend Overrider

  override def foo
  end
end # => raise

for Production

If you want to disable Overrider, write Overrider.disable = true at first line. If Overrider is disabled, TracePoint never runs, and so there is no overhead of VM instruction.

Examples

include module method after override method

module C1
  def foo
  end
end

class C2
  extend Overrider

  override def foo
  end

  include C1
end # => OK

singleton method

class D1
end

class D2 < D1
  extend Overrider

  class << self
    def foo
    end
  end

  override_singleton_method :foo
end # => raise

class D2_1
  def self.foo
  end
end

class D2_2 < D2_1
  extend Overrider

  class << self
    def foo
    end
  end

  override_singleton_method :foo
end # => OK

extend singleton method after override method

module E1
  def foo
  end

  def bar
  end
end

class E2
  extend Overrider

  class << self
    def foo
    end

    def bar
    end
  end

  override_singleton_method :foo
  override_singleton_method :bar

  extend E1
end # => OK

Class.new style

class A1
  def foo
  end
end

Class.new(A1) do
  extend Overrider

  override def foo
  end
end # => OK

How is it implemented?

Use TracePoint and caller_locations (to detect class-end or Class.new { }).

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/joker1007/overrider.

License

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