State across pages · level 2 of 5 · Terra Supply
One action usually has several observable effects. Assert every effect the user depends on, not just the convenient one.
Add a product to the cart in Terra Supply and prove both things the user relies on:
0 to 1.These are two separate promises the app makes. A test that checks only one of them stays green while the other silently breaks.
We break each one in a copy of the app. Your test has to fail on every copy.