Making Rails tests aware of Rack middleware outside Rails's internal chain

Question

Context: an application uses a piece of Rack middleware that must be setup in config.ru, rather than Rails\'s internal Middleware chain. This i

Answer 1

I think the problem is that ActionDispatch::IntegrationTest uses your Rails.application as its Rack app for the test.

So, if you can wrap that Rack::Rewrite rule into some Rack middleware, you should be able to override the Rack app you're testing in your test with:

ActionDispatch::IntegrationTest.app = MyRewriteMiddleware