Fixes exception in AbstractPGNWriter.getPGN if history contains bad move

src/main/java/com/fathzer/jchess/pgn/AbstractPGNWriter.java

@@ -13,9 +13,9 @@
 import com.fathzer.games.MoveGenerator;
 import com.fathzer.games.Status;
 import com.fathzer.jchess.fen.FENUtils;
+import com.fathzer.jchess.pgn.MoveAlgebraicNotationBuilder.IllegalMoveException;
 
 public abstract class AbstractPGNWriter<M, B extends MoveGenerator<M>> {
-	//TODO why DATE_FORMAT is public
 	public static final DateTimeFormatter DATE_FORMAT = DateTimeFormatter.ofPattern("yyyy.MM.dd");
 
 	private static record ResultAndMoves (Status status, List<String> anMoves) {
@@ -98,7 +98,13 @@ private ResultAndMoves getMovesAndResult(GameHistory<M, B> history) {
 			} else {
 				buf.append(" ");
 			}
-			buf.append(getAlgebraicNotation(move, board));
+			String moveString;
+			try {
+				moveString = getAlgebraicNotation(move, board);
+			} catch (IllegalMoveException e) {
+				moveString = "{ Illegal move "+e.getMoveRepresentation()+" }";
+			}
+			buf.append(moveString);
 		}
 		if (buf.length()!=0) {
 			result.add(buf.toString());

src/main/java/com/fathzer/jchess/pgn/MoveAlgebraicNotationBuilder.java

@@ -19,6 +19,21 @@
 /** A class to get <a href="https://en.wikipedia.org/wiki/Algebraic_notation_(chess)">Algebraic notation</a> of moves.
  */
 public class MoveAlgebraicNotationBuilder {
+
+	public class IllegalMoveException extends IllegalArgumentException {
+		private static final long serialVersionUID = 1L;
+		private final String moveRepresentation;
+
+		private IllegalMoveException(String message, String moveRepresentation) {
+			super(message);
+			this.moveRepresentation = moveRepresentation;
+		}
+
+		public String getMoveRepresentation() {
+			return this.moveRepresentation;
+		}
+	}
+
 	private String checkSymbol = "+";
 	private String checkmateSymbol = "#";
 	private char captureSymbol = 'x';
@@ -28,11 +43,11 @@ public class MoveAlgebraicNotationBuilder {
 	private boolean playMove;
 
 	/** Gets the algebraic notation of a move.
-	 * <br>If sideEffect attribute is true, move is played on the board
+	 * <br>If playMove attribute is true, move is played on the board
 	 * @param board The board before the move occurs
 	 * @param move The move to encode
 	 * @return The move in algebraic notation
-	 * @throws IllegalArgumentException if move is invalid
+	 * @throws IllegalMoveException if move is invalid
 	 */
 	public String get(Board<Move> board, Move move) {
 		final StringBuilder builder = new StringBuilder();
@@ -42,7 +57,8 @@ public String get(Board<Move> board, Move move) {
 		final int to = move.getTo();
 		final List<Move> candidates = StreamSupport.stream(state.spliterator(),false).filter(m -> m.getTo()==to).toList();
 		if (!checkValidMove(move, candidates)) {
-			throw new IllegalArgumentException("Move "+moveToString(move, board)+" is not valid");
+			final String moveString = moveToString(move, board).toString();
+			throw new IllegalMoveException("Move "+moveString+" is not valid", moveString);
 		}
 		final Piece moved = board.getPiece(move.getFrom());
 		final Castling castling = moved.getKind()==KING ? board.getCastling(move.getFrom(), to) : null;
@@ -58,7 +74,7 @@ public String get(Board<Move> board, Move move) {
 		return builder.toString();
 	}
 
-	private CharSequence moveToString(Move move, Board<Move> board) {
+	private static CharSequence moveToString(Move move, Board<Move> board) {
 		final StringBuilder buf = new StringBuilder();
 		final CoordinatesSystem cs = board.getCoordinatesSystem();
 		buf.append(cs.getAlgebraicNotation(move.getFrom()));

src/test/java/com/fathzer/jchess/pgn/MoveAlgebraicNotationTest.java

@@ -11,6 +11,7 @@
 import com.fathzer.jchess.MoveBuilder;
 import com.fathzer.jchess.Piece;
 import com.fathzer.jchess.fen.FENUtils;
+import com.fathzer.jchess.pgn.MoveAlgebraicNotationBuilder.IllegalMoveException;
 
 class MoveAlgebraicNotationTest implements MoveBuilder {
 
@@ -57,11 +58,11 @@ void test() {
 		// Illegal moves
 		final Board<Move> board2 = (Board<Move>) board.fork();
 		final Move move2 = move(board, "f3","g2");
-		assertThrows(IllegalArgumentException.class, () -> san.get(board2, move2));
+		assertThrows(IllegalMoveException.class, () -> san.get(board2, move2));
 
 		final Board<Move> board3 = FENUtils.from("2kr3r/Rppppppp/8/8/2P1Q2Q/1P3K2/2PP2PP/RNB4Q w - - 0 1");
 		final Move move3 = move(board, "a7","a8", Piece.WHITE_QUEEN);
-		assertThrows(IllegalArgumentException.class, () -> san.get(board3, move3));
+		assertThrows(IllegalMoveException.class, () -> san.get(board3, move3));
 	}
 
 	@Test

src/test/java/com/fathzer/jchess/pgn/PGNWriterTest.java

@@ -8,6 +8,8 @@
 import org.junit.jupiter.api.Test;
 
 import com.fathzer.games.GameHistory;
+import com.fathzer.games.GameHistory.TerminationCause;
+import com.fathzer.games.Status;
 import com.fathzer.jchess.Board;
 import com.fathzer.jchess.GameBuilders;
 import com.fathzer.jchess.Move;
@@ -34,7 +36,6 @@ void test() {
 				.setEvent("A competition").setRound(5L).setSite("there").setDate(LocalDate.of(2020, 1, 8))
 				.build();
 		final List<String> pgn = writer.getPGN(headers, history);
-		System.out.println(pgn); //TODO
 		assertEquals("[Event \"A competition\"]", pgn.get(0));
 		assertEquals("[Site \"there\"]", pgn.get(1));
 		assertEquals("[Date \"2020.01.08\"]", pgn.get(2));
@@ -79,4 +80,17 @@ void nonStandardStartFENTest() {
 		final var fenIndex = pgn.indexOf("[FEN \"1r2k1r1/ppp1pp2/3p2pp/5bn1/P7/2N2B2/1PPPPP2/RR2K3 w Q - 4 11\"]");
 		assertTrue(fenIndex>setUpIndex);
 	}
+
+	@Test
+	void illegalMoveTest() {
+		final var board = FENUtils.from(FENUtils.NEW_STANDARD_GAME);
+		final var history = new GameHistory<>(board);
+		history.add(move(board, "e2", "e4"));
+		final Move illagalMove = move(board, "a1","a1");
+		assertFalse(history.add(illagalMove));
+		history.earlyEnd(Status.WHITE_WON, TerminationCause.RULES_INFRACTION);
+		final var writer = new PGNWriter();
+		final List<String> pgn = writer.getPGN(new PGNHeaders.Builder().build(), history);
+		assertEquals("1. e4 { Illegal move a1-a1 }", pgn.get(pgn.size()-1));
+	}
 }