docs(bot): clarify when scoreMove early-return fires

2026-04-28 13:52:22 -04:00
parent aa7bc30ee1
commit ebd1463b0a
1 changed files with 5 additions and 1 deletions
@@ -82,7 +82,11 @@ export class CasualBrain implements Brain {
    if (!destPiece) score += 50;

    const piece = view.pieces[move.from];
-    if (!piece) return score; // shouldn't happen, but safe.
+    // Reachable when scoring tests pass minimal fixture views. In real play
+    // the candidate's `from` is always one of our pieces (since candidates
+    // came from `legalCandidates` over our own squares), but the early
+    // return keeps unit tests from needing full board fixtures.
+    if (!piece) return score;

    const ownStartingRank = this.color === 'w' ? '1' : '8';
    const ownPawnStartingRank = this.color === 'w' ? '2' : '7';