#engineering

The green test that measured nothing

A test suite can be green because the system works, or green because the test points at nothing. We collected our own specimens: a suite verifying a build nobody shipped, a read-only gate over a collector that could not load, a published guarantee table that never executed, a pinned assertion that was a fossil of a bug, and a suite that proved every rule and never ran the handler. Each one with the code, and the one-line question that catches all five.

11 August 2026·7 min read