ruby - How to test 404 Sinatra::NotFound errors with Rack::Test? -

i have application raises 404 sinatra::notfound errors on production when route missing.

however, following test passes:

it 'should not raise error'   expect{ '/unknown_path' }.to_not raise_error end 

why don't 404 sinatra::notfound errors raised in test?

the following raise error , cause test fail:

get '/unknown_path'   raise 'error' end 

how test 404 sinatra::notfound errors?

try this:

get '/unknown_path' assert_equal last_response.status, 404