I Built C++ Test Impact Analysis With Zero Runtime Dependencies

Описание и применение

diff2test — это CLI‑утилита, которая, используя только метаданные, созданные CMake, CTest и компилятором, определяет, какие тесты CTest необходимо запустить после изменения файлов, уменьшая время CI без добавления зависимостей.

Задача

Running the full C++ test suite after every change is expensive; need to run only affected tests without adding runtime dependencies.

Результат

diff2test reduces test execution time by selecting only impacted tests while remaining zero‑dependency at runtime.

Рабочий процесс

• Collect changed file paths via git diff or stdin
• Provide a list of compiler .d files via --dep-list
• Read CMake File API JSON for targets and sources
• Read CTest JSON for test definitions
• Build reverse dependency graph from targets to tests
• Propagate impact from changed files to affected tests
• Validate evidence; if missing, exit with FULL_SUITE_SELECTED or FULL_SUITE_REQUIRED
• Output selected test names or exit code 0 for subset

Доказательства

If something important is missing or suspicious, the optimization disappears.

Источник

The program would not produce its own evidence. It would consume evidence.

Источник

The successful narrow case is: SUBSET_SELECTED exit 0

Источник