25年使われてきた最小C++単体テストフレームワークの近代化（パート2）
この記事は、四半世紀にわたって使われてきた最小限のC++単体テストフレームワークを最新化するプロセスのパート2です。レガシーコードの分析、現代のC++標準への対応、そして後方互換性を維持しながらのリファクタリング手法について詳述しています。
背景メモ
- Part 2 of a series that refactors an ancient (1999-era) C++ unit testing library, "CppUnitLite", originally created by C++ expert Michael Feathers. Feathers was a key figure in the "Working Effectively with Legacy Code" era and a pioneer of unit testing in C++.
- CppUnitLite was deliberately minimal: it compiled in seconds and had zero dependencies, contrasting with heavyweight frameworks like CppUnit. It became legendary among C++ veterans but predates modern C++ standards (C++11/14/17/20).
- This installment shows how to modernize the framework using templates, constexpr, lambdas, and modern CMake — changes that reflect how C++ has evolved over 25 years while preserving the original's lean philosophy.
- The series matters because it documents a real-world legacy-code modernization with explicit before/after comparisons, a skill critical for the many C++ codebases still running on older idioms.