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guhillingguhilling
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- Lecture on Thursday, 5th, 2026.
1 parent 4adb670 commit cf139d5

11 files changed

Lines changed: 238 additions & 161 deletions

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‎2026-02-05-Retro_Copilot/src/main/java/de/hilling/chess/ChessException.java‎

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package de.hilling.chess;
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public class ChessException extends RuntimeException {
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}

‎2026-02-05-Retro_Copilot/src/main/java/de/hilling/chess/ChessGame.java‎

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package de.hilling.chess;
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import java.util.LinkedList;
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import java.util.List;
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/**
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* A (not so) small example for a chessboard maybe understanding Long algebraic notation (@see <a
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* href="https://en.wikipedia.org/wiki/Algebraic_notation_(chess)#Long_algebraic_notation">Wikipedia</a>).
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*/
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public class ChessGame {
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private ChessPiece[][] board = new ChessPiece[8][8];
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private List<String> moves = new LinkedList<>();
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public ChessGame() {
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for(int x=0; x<8; x++) {
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setPieceForWhiteAndBlack(PieceType.PAWN, x, 1);
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}
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setPieceForWhiteAndBlack(PieceType.KING, 4, 0);
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setPieceForWhiteAndBlack(PieceType.ROOK, 0, 0);
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setPieceForWhiteAndBlack(PieceType.ROOK, 7, 0);
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setPieceForWhiteAndBlack(PieceType.KNIGHT, 1, 0);
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setPieceForWhiteAndBlack(PieceType.KNIGHT, 6, 0);
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setPieceForWhiteAndBlack(PieceType.BISHOP, 2, 0);
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setPieceForWhiteAndBlack(PieceType.BISHOP, 5, 0);
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setPieceForWhiteAndBlack(PieceType.QUEEN, 3, 0);
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}
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private void setPiece(PieceType pieceType, Color color, int x, int y) {
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board[x][y] = new ChessPiece(pieceType, color);
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}
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private void setPieceForWhiteAndBlack(PieceType pieceType, int x, int y) {
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setPiece(pieceType, Color.WHITE, x, y);
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setPiece(pieceType, Color.BLACK, x, 7-y);
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}
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public ChessPiece get(Position position) {
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return board[position.x][position.y];
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}
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public String toString() {
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StringBuilder sb = new StringBuilder();
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sb.append("-----------------\n");
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for(int y=7; y>=0; y--) {
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sb.append('|');
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for(int x=0; x<8; x++) {
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ChessPiece piece = board[x][y];
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if(piece != null) {
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sb.append(piece.toString());
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} else {
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sb.append(' ');
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}
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if(x<7) {
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sb.append(' ');
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}
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}
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sb.append("|\n");
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}
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sb.append("-----------------");
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return sb.toString();
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}
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public void move(String move) {
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if(move.length() != 4) {
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throw new IllegalArgumentException("Move must be 4 characters long");
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}
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Position from = Position.of(move.substring(0, 2));
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Position to = Position.of(move.substring(2, 4));
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ChessPiece fromPiece = board[from.x][from.y];
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if(fromPiece != null) {
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board[to.x][to.y] = fromPiece;
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board[from.x][from.y] = null;
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moves.add(move);
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} else {
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throw new IllegalArgumentException("no piece on " + from);
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}
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}
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public String getMoves() {
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String result = "";
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for(String move : moves) {
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result = result + move + '\n';
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}
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return result;
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}
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}

‎2026-02-05-Retro_Copilot/src/main/java/de/hilling/chess/ChessPiece.java‎

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package de.hilling.chess;
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public class ChessPiece {
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public final PieceType type;
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public final Color color;
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public ChessPiece(PieceType type, Color color) {
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this.type = type;
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this.color = color;
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}
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@Override
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public String toString() {
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return switch (color) {
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case WHITE -> type.shortcut().toUpperCase();
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case BLACK -> type.shortcut();
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};
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}
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}

‎2026-02-05-Retro_Copilot/src/main/java/de/hilling/chess/Color.java‎

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package de.hilling.chess;
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public enum Color {
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WHITE,
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BLACK
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}

‎2026-02-05-Retro_Copilot/src/main/java/de/hilling/chess/PieceType.java‎

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package de.hilling.chess;
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/**
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* Describe the type and include the shortcut for the piece.
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*/
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public enum PieceType {
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PAWN,
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KNIGHT,
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ROOK,
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QUEEN,
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KING,
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BISHOP;
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public String shortcut() {
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if(this == KNIGHT) {
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return "n";
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} else {
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return name().substring(0, 1).toLowerCase();
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}
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}
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}

‎2026-02-05-Retro_Copilot/src/main/java/de/hilling/chess/Position.java‎

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import java.util.HashMap;
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import java.util.Map;
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import java.util.regex.Pattern;
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import org.jspecify.annotations.NonNull;
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‎2026-02-05-Retro_Copilot/src/main/java/de/hilling/chess/Sort.java‎

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This file was deleted.

‎2026-02-05-Retro_Copilot/src/test/java/de/hilling/chess/ChessGameTest.java‎

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package de.hilling.chess;
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import static org.junit.jupiter.api.Assertions.assertEquals;
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import static org.junit.jupiter.api.Assertions.fail;
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import org.junit.jupiter.api.BeforeEach;
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import org.junit.jupiter.api.Test;
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class ChessGameTest {
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private static final String STARTPOSITION = """
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-----------------
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|r n b q k b n r|
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|p p p p p p p p|
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| |
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| |
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| |
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| |
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|P P P P P P P P|
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|R N B Q K B N R|
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-----------------""";
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private static final String E2E4_POSITION = """
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-----------------
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|r n b q k b n r|
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|p p p p p p p p|
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| |
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| |
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| P |
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| |
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|P P P P P P P|
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|R N B Q K B N R|
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-----------------""";
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private static final String E2E4E7E5_POSITION = """
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-----------------
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|r n b q k b n r|
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|p p p p p p p|
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| |
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| p |
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| P |
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| |
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|P P P P P P P|
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|R N B Q K B N R|
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-----------------""";
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private ChessGame chessGame;
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@BeforeEach
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void setUp() {
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chessGame = new ChessGame();
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}
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// TODO: test more pieces, refactoring
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@Test
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void testSetup() {
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ChessPiece whitePawn = chessGame.get(Position.of(1, 1));
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assertEquals(PieceType.PAWN, whitePawn.type);
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assertEquals(Color.WHITE, whitePawn.color);
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ChessPiece blackPawn = chessGame.get(Position.of(7, 6));
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assertEquals(PieceType.PAWN, blackPawn.type);
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assertEquals(Color.BLACK, blackPawn.color);
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}
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@Test
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void testSetupToString() {
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assertEquals(STARTPOSITION, chessGame.toString());
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}
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@Test
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void illegalMoveLength() {
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try {
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chessGame.move("a2a4bb");
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fail("Illegal move exception");
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} catch (IllegalArgumentException iae) {
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// nothing to do
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}
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}
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@Test
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void illegalMoveCharacters() {
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try {
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chessGame.move("a2z4");
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fail("Illegal move exception");
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} catch (IllegalArgumentException iae) {
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assertEquals("Illegal position: z4", iae.getMessage());
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}
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}
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@Test
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void movePawn() {
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chessGame.move("e2e4");
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assertEquals(E2E4_POSITION, chessGame.toString());
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}
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@Test
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void movePawns() {
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chessGame.move("e2e4");
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chessGame.move("e7e5");
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assertEquals(E2E4E7E5_POSITION, chessGame.toString());
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assertEquals("e2e4\ne7e5\n", chessGame.getMoves());
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}
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}

‎2026-02-05-Retro_Copilot/src/test/java/de/hilling/chess/PositionGenericsTest.java‎

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‎2026-02-05-Retro_Copilot/src/test/java/de/hilling/chess/PositionTest.java‎

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package de.hilling.chess;
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import org.junit.jupiter.api.Test;
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import static org.junit.jupiter.api.Assertions.*;
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import org.junit.jupiter.api.Test;
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class PositionTest {
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@Test

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