https://srdusr.com/tags/testing/Recent content in Testing on srdusrHugoen-usThu, 03 Sep 2026 05:12:40 +0200https://srdusr.com/blog/tests-cannot-see-what-the-machine-already-has/Wed, 08 Apr 2026 00:00:00 +0000https://srdusr.com/blog/tests-cannot-see-what-the-machine-already-has/<p>Code that creates a precondition stops being exercised on the machine where that precondition already holds. The development machine ran the setup path once and never runs it again, so the setup path can break completely and stay green.</p> <h2 id="why-it-holds">Why it holds</h2> <p>A test asserts behaviour given a state. The state on a working machine is the state after setup succeeded. Every branch that runs only when setup has <em>not</em> happened is therefore unreachable from that machine, and unreachable code is untested code no matter what the coverage report says.</p>