sinatra_reloader.rb

# Development mode reloading
class Sinatra::Reloader < Rack::Reloader
    def safe_load(file, mtime, stderr = $stderr)
        if file == __FILE__
            ::Sinatra::Application.reset!
            stderr.puts "#{self.class}: reseting routes"
        end
        super
    end
end

configure :development do
    use Sinatra::Reloader
end