Testing, Verification & Next Steps

Every feature SKYWATCH has now is real, wired end to end, and running. This closing module doesn’t add another feature — it does three things instead: puts real automated tests around the logic that’s most worth protecting, walks the entire finished app feature by feature to confirm everything built across five modules still works together, and points at what a reader would reasonably build next.

Why This Matters

A course that ends the moment the last feature ships teaches you to build, but not to know whether what you built still works after the next change. The detection engine from Module 2 and the geo math from Modules 2 and 5 are exactly the kind of code worth pinning down with tests — pure functions, no I/O, easy to get subtly wrong, and easy to break silently while working on something else entirely. The verification pass after that isn’t busywork either: five modules of features interacting is exactly where a regression hides.

What You’ll Learn

• Setting up Vitest and writing real unit tests for the detection engine and the geo helpers, including the one stateful-module gotcha both test files need to handle correctly
• A full, module-by-module manual verification pass across the finished app, plus the mechanical typecheck/lint/build checks that have been available since Module 1
• What’s deliberately out of scope, why, and how the patterns you’ve already learned extend directly to each one if you want to keep building

Outcome

By the end of this module, you’ll have a small but meaningful test suite, a verified, working application, and a clear map of where to take SKYWATCH next.

Let’s finish it.