Rails/Devise: testing the user confirmation process

BACK STORY: I’m working on a Rails app template that is similar to the
Rails Tutorial Sample App. The idea is to begin every app I ever start
with a pre-made template so that I don’t have to plow through chapters 3
through 10 in Rails tutorial. I can have the app set up AND tested in
a few minutes. My source code is at
https://github.com/jhsu802701/generic_app_template .

MY TASK: I’m in the process of replacing the Sample App’s original user
authentication system with the devise gem. How do you set up the
integration test for the CONFIRMATION process? When users sign up or
change their email addresses, they are sent a link. When they visit
URL, they are confirmed.

MY PROBLEM: Are there any good examples on how to test the user
confirmation process? In Minitest/Capybara tests I’ve set up, visiting
links doesn’t seem to confirm the URL, and I get error messages saying
I used the wrong confirmation code. I can’t possibly be the first
in the history of the world to try to do this, right?