https://nalar.dev/tags/legacy-code/ Recent content in Legacy Code on Nalar Hugo en-us Thu, 03 Sep 2026 00:00:00 +0700 https://nalar.dev/characterization-tests-for-safe-legacy-changes/ Thu, 03 Sep 2026 00:00:00 +0700 https://nalar.dev/characterization-tests-for-safe-legacy-changes/ <p>Changing old code is difficult when nobody can say with confidence which behaviours are intentional and which are accidents. Documentation may be incomplete, the original authors may be unavailable, and existing tests may cover only a small part of the system.</p> <p>In that situation, writing tests for the design you wish the code had can be risky. Before improving the design, you first need evidence about what the software actually does today.</p>