chess-engine-development

name	chess-engine-development
description	Use when changing ACE engine behavior, including board state, move making, move generation, evaluation, search, or UCI integration.

Chess Engine Development

Use this skill for ACE core engine changes. ACE is a C++20 chess engine with a 120-square mailbox board, pawn bitboards, GoogleTest tests, and CMake presets.

Workflow

1. Identify the affected module: board, search, io, main, or utils.
2. Read the relevant headers and tests before editing implementation files.
3. Keep the change scoped to one behavior or bug.
4. Add or update unit tests in test/unittest/ for localized behavior.
5. Run perft when move generation or make/undo behavior changes.

Validation

Use the smallest relevant validation command:

cmake --preset dev
cmake --build --preset dev
ctest --test-dir build-dev -R unittest --output-on-failure

For move-generation or make/undo changes:

PERFT_MAX_DEPTH=4 ctest --test-dir build-dev -R perfttest --output-on-failure

For warning-sensitive or release-readiness changes:

cmake --preset prod
cmake --build --preset prod
ctest --preset prod

Guardrails

• Do not change chess rules without regression coverage.
• Do not rewrite unrelated modules while fixing a localized issue.
• Preserve existing public headers and target structure unless the task requires a broader refactor.
• Prefer FEN-based tests for board positions.