beginning of transition

app/chess_sim/test.py

@@ -65,6 +65,7 @@ def run_random_games(n: int = 20, max_moves: int = 200, verbose: bool = False):
 def test_castling_kingside_both_sides():
     board = ChessBoard.init_default()
 
+    # rewrite with  boardmove from string
     seq = [
         (BoardMove(BoardPos((7, 6)), BoardPos((5, 5))), Color.WHITE),
         (BoardMove(BoardPos((0, 1)), BoardPos((2, 2))), Color.BLACK),
@@ -139,6 +140,32 @@ def main():
     test_castling_kingside_both_sides()
     run_random_games(verbose=False)
 
+    board = ChessBoard.init_default()
+    # helper to create boardmove from two-square string
+    def bm(s):
+        return BoardMove(
+            ChessBoard.algebraic_to_pos(s[0:2]),
+            ChessBoard.algebraic_to_pos(s[2:4])
+        )
+
+    # perform four cycles of the knight shuffle
+    # Nf3-Nf6-Ng1-Ng8 and returns to the starting position.
+    seq = []
+    for _ in range(4):
+        seq.extend([
+            (bm("g1f3"), Color.WHITE),
+            (bm("g8f6"), Color.BLACK),
+            (bm("f3g1"), Color.WHITE),
+            (bm("f6g8"), Color.BLACK),
+        ])
+    for move, color in seq:
+        ok = board.make_move(move, color)
+        assert ok, "repetition test move failed"
+
+    rep = board.highest_repetiton_amount()
+    assert rep >= 5, f"expected at least 5 repetitions, got {rep}"
+    assert board.is_fivefold_repetition(), "board should report fivefold repetition"
+
     print(f"all tests passed")