rack middleware to simulate PATCH by _name=POST

patch_simulating_middleware.rb

class PatchSimulatingMiddleware
  def initialize app
    @app = app
  end

  def call env
    request = Rack::Request.new(env)

    if request.post? && ( request.params['_name'] == 'patch' )
      request.set_header 'REQUEST_METHOD', 'PATCH'
    end

    @app.call env
  end
end

#application.rb
config.middleware.use PatchSimulatingMiddleware