2,085 Tests, and None of Them Opens the Front Door
A solo developer audits 22 repositories and finds over 2,000 tests, yet only one repository runs them in CI. The tests excel at static invariants—like preventing unscoped database reads or accidental static rendering—but fail to cover browser-level journeys: signed-in transactions, live sign-on, multi-tenant routing, and accessibility across most apps. The author argues that the gap isn't coverage but wiring: tests that never run are just documentation. He advocates for plain-English end-to-end tests to fill the empty tier, while preserving the fast, deterministic unit tests that no browser can replace.
A test that nothing runs is documentation.
- perrygeo
Anecdote time: I worked on a project with a senior dev who was really into unit testing and only unit testing. The software had to be fully tested as tiny little lego bricks with mocks galore. Because "if all the pieces were correct, the combination had to be correct" - his words. (I guess he'd never considered emergent behavior)
I'll never forget the cycle, after staunch objections to integration/e2e/manual tests and zealously insisting on full unit test coverage, the senior dev deployed changes ... boom. The process failed hard minutes after start because there was a bug in main. Full production outage. A bug so obvious we should have caught it by eye. Clearly, in the weeks developing the feature, he had never bothered to even run the application. Each part was fully polished in isolation but utterly failed when integrated into an application.
The way I've come to think of it: Unit tests are for libraries, a closed world where you can neatly define all inputs and outputs. Integration/E2E tests are for applications, an open world which require systems thinking, simulations not proofs. Know which world you're working in!
- netsharc
Skimmed through this. One heading is "The gap was never coverage. It was wiring.". Smeḷls very AI sloppy, won't bother reading...
I used to read anything and everything on HN, but my allergy to slop has made me stop doing that. I suppose that's a good thing?
- KenPainter
Your Website seems to be messing with browser history. Back button will not take you back to HN.