https://codeinstances.com/tags/shrink/ Recent content in Shrink on CodeInstances.com Hugo en-us Sun, 18 Oct 2026 00:00:00 +0000 https://codeinstances.com/codeinstances-shrinks-a-failing-run-to-the-answer-that-breaks-it-and-keeps-it-as-a-test/ Sun, 18 Oct 2026 00:00:00 +0000 https://codeinstances.com/codeinstances-shrinks-a-failing-run-to-the-answer-that-breaks-it-and-keeps-it-as-a-test/ <p>CodeInstances v0.3.0 adds two verbs at once. <code>codeinstances shrink</code> takes a failing run and a passing one and finds which of the failing run&rsquo;s answers actually cause the failure. <code>codeinstances test</code> replays a folder of instances as regression tests. They belong together: the first finds the bug&rsquo;s smallest form, the second makes sure it stays fixed.</p> <p>Here&rsquo;s the problem shrink goes after. You&rsquo;ve got a run that fails and one that doesn&rsquo;t, and <code>diff</code> from the last release shows you how they differ. Often that&rsquo;s dozens of answers: timestamps, ids, counters, prices that moved. One of them broke the program, and the rest is noise. Reading them one by one is slow, and it&rsquo;s guesswork.</p>