COMPATIBILITY.md

Compatibility with Other Middlewares

Rack::Deflater

Some people ask rack-dev-mark does not work with Rack::Delfater. Those who ask this question typically insert Rack::Deflater by config.middleware.use Rack::Deflater. To deflate all the response including the error pages, you need to put the middleware before ActionDispatch::ShowExceptions. So the order of those 3 middlewares including rack-dev-mark looks like below.

use Rack::Deflater
use Rack::DevMark::Middleware
use ActionDispatch::ShowExceptions

To make the order above, you can have the following settings for Rack::Deflater.

module MyApp
  class Application < Rails::Application
    config.middleware.insert_before ActionDispatch::ShowExceptions, Rack::Deflater
  end
end

Of course, you can stick the config.middleware.use Rack::Deflater by the following settings for rack-dev-mark.

module MyApp
  class Application < Rails::Application
    config.rack_dev_mark.insert_after Rack::Deflater
  end
end