We also use a home-made RspecFlaky::Listener listener which records flaky examples in a JSON report file on master (retrieve-tests-metadata and update-tests-metadata jobs).

a technique that enable a test suite to perform as well as using fixtures (or better if you're running just a few tests from the suite) and read as good as you are used to when using factories

No need for DatabaseCleaner (rolling back transactions are usually faster than truncate).

But where is the helper method defined? What’s its visibility? Can I put it in a module? Can I use inheritance? Who can call it? Can I call super from the extracted method? If so, where does super go?

minitest doesn't reinvent anything that ruby already provides, like: classes, modules, inheritance, methods. This means you only have to learn ruby to use minitest and all of your regular OO practices like extract-method refactorings still apply.

heavily inspired in RSpec Expectations