How do you test payment failures / weird edge cases in your app?

I'm working on a SaaS app and honestly this part is driving me crazy.

Things like:

card declines

webhook delays

user gets charged but DB fails

retry loops breaking UI

Right now I'm doing:

- Stripe test cards (limited)

- manually editing DB

- throwing random errors in code

Still feels unreliable and super time consuming.

Curious how others handle this?

Do you have a proper workflow for testing

- failures

- edge cases

- real-world scenarios

Or do you just hack around it like me?

Author: intchu