How to make a subscription test?

I am using Woocommere with the Subscription extension. I have a tons of plugins, selfwritten as-well as external that change behavior of subscription renewals (adding special meta keys, special discount, etc.).

I want to write feature tests like this:

 public function test_subscription() 
 {
    $subscription = $this->create_subscription([..]);
    $subscription->renewal([..]);
    $this->assertTrue('15%', $subscription->getMetaKey('discount'));
  }

So I would like to trigger subscriptions and order processing and see if my WP together with all plugins has the expected output.

My question is, is there a library that I can use for that?

I found https://developer.woocommerce.com/testing-extensions-and-maintaining-quality-code/setting-up-a-local-environment-for-testing/ and I believe my test is considered an “End-to-end” test? I believe “WooCommerce Core E2E Tests ” comes closest, as it seems to support cases like changing order status. But how can I create tests for subscriptions?

I also checked out https://woocommerce.com/document/testing-subscription-renewal-payments/ but this does not mention automated tests.

I also found this test suite https://github.com/Automattic/woocommerce-subscriptions-core but from the docs alone I don’t really understand how to integrate those test with my own wordpress application. It seems to just write test for plain WP with subscription plugin?

Would be happy about any advice.