runner.rb

class Runner

  def run(&block)
    begin
      instance_exec(&block)
      @on_success.call if @on_success
    rescue Exception => ex
      @on_failure.call(ex) if @on_failure
    end
  end

  def on_success(&block)
    @on_success = block
  end

  def on_failure(&block)
    @on_failure = block
  end

end

obj = Runner.new
obj.run do
  on_success do
    puts "on success"
  end
  on_failure do |ex|
    puts "on failure #{ex.inspect}"
  end
  raise
end