Add corresponding tests

app/src/main/java/ch/nuth/zhaw/exbox/AnyServer.java

@@ -5,7 +5,7 @@ package ch.nuth.zhaw.exbox;
  *
  */
 public class AnyServer implements CommandExecutor {
-    //----- Dies implementiert das CommandExecutor Interface.
+    // ----- Dies implementiert das CommandExecutor Interface.
     @Override
     public String execute(String command) {
         return "Die Eingabe ist \"" + command + "\"\n";

app/src/main/java/ch/nuth/zhaw/exbox/App.java

@@ -10,4 +10,4 @@ public class App {
         f.setLocationRelativeTo(null);
         f.setVisible(true);
     }
-}
+}

app/src/main/java/ch/nuth/zhaw/exbox/BracketServer.java

@@ -13,6 +13,7 @@ public class BracketServer implements CommandExecutor {
 
     public BracketServer() {
         super();
+
         bracketPairs = new HashMap<>() {
             {
                 put("(", ")");
@@ -37,9 +38,8 @@ public class BracketServer implements CommandExecutor {
         for (MatchResult result : results) {
             if (bracketPairs.keySet().contains(result.group())) {
                 openBrackets.push(result.group());
-            } else if (
-                !openBrackets.isEmpty() &&
-                result.group().equals(bracketPairs.get(openBrackets.peek()))) {
+            } else if (!openBrackets.isEmpty() &&
+                    result.group().equals(bracketPairs.get(openBrackets.peek()))) {
                 openBrackets.pop();
             } else {
                 return false;

app/src/main/java/ch/nuth/zhaw/exbox/CommandExecutor.java

@@ -17,4 +17,4 @@ public interface CommandExecutor {
      * @return Resultat, ueblicherweise eine oder mehrere Zeilen.
      */
     String execute(String command) throws Exception;
-}
+}

app/src/main/java/ch/nuth/zhaw/exbox/Competitor.java

@@ -10,7 +10,7 @@ public class Competitor implements Comparable<Competitor> {
     private final String time;
     private int rank;
 
-    public Competitor(int rank, String name, String time)  {
+    public Competitor(int rank, String name, String time) {
         this.rank = rank;
         this.name = name;
         this.time = time;
@@ -32,22 +32,20 @@ public class Competitor implements Comparable<Competitor> {
         return name;
     }
 
-    private static long parseTime(String s)  {
+    private static long parseTime(String s) {
         try {
             DateFormat sdf = new SimpleDateFormat("HH:mm:ss");
             Date date = sdf.parse(s);
             return date.getTime();
-        } catch (Exception e) {System.err.println(e);}
+        } catch (Exception e) {
+            System.err.println(e);
+        }
+
         return 0;
     }
 
-    private static String timeToString(int time) {
-        SimpleDateFormat df = new SimpleDateFormat("HH:mm:ss");
-        return df.format(new Date(time));
-    }
-
     public String toString() {
-        return ""+ rank + " "+name+" "+time;
+        return "" + rank + " " + name + " " + time;
     }
 
     @Override
@@ -66,12 +64,11 @@ public class Competitor implements Comparable<Competitor> {
     }
 
     @Override
-    public boolean equals (Object o) {
+    public boolean equals(Object o) {
         if (o instanceof Competitor) {
-            Competitor c = (Competitor)o;
+            Competitor c = (Competitor) o;
             return compareTo(c) == 0;
-        }
-        else {
+        } else {
             return false;
         }
     }
@@ -91,8 +88,7 @@ class AlphaComparatorCompetitor implements Comparator<Competitor> {
 
         if (result == 0) {
             return Long.compare(o1.getTimeValue(), o2.getTimeValue());
-        }
-        else {
+        } else {
             return result;
         }
     }

app/src/main/java/ch/nuth/zhaw/exbox/ExBoxFrame.java

@@ -17,16 +17,16 @@ import java.util.Set;
 /**
  * @(#)ExBoxFrame.java
  *
- * JFC ExBox application
+ *                     JFC ExBox application
  *
  * @author K.Rege
- * @version	1.00 2014/2/3
- * @version	1.01 2016/8/2
- * @version	2.00 2017/8/30 Test
- * @version	2.01 2018/2/5 AutoscaleFaktor
- * @version	2.02 2018/3/12 Reconnect (inspired by S. Kunz)
- * @version	2.03 2021/7/24 Test (repeat)
- * @version	2.04 2021/9/11 Test as plugin
+ * @version 1.00 2014/2/3
+ * @version 1.01 2016/8/2
+ * @version 2.00 2017/8/30 Test
+ * @version 2.01 2018/2/5 AutoscaleFaktor
+ * @version 2.02 2018/3/12 Reconnect (inspired by S. Kunz)
+ * @version 2.03 2021/7/24 Test (repeat)
+ * @version 2.04 2021/9/11 Test as plugin
  */
 public class ExBoxFrame extends JFrame implements ActionListener, ItemListener {
 	private final int UHDTHRESHOLD = 1920;
@@ -48,9 +48,11 @@ public class ExBoxFrame extends JFrame implements ActionListener, ItemListener {
 
 	public void setFontSize(int size) {
 		Set<Object> keySet = UIManager.getLookAndFeelDefaults().keySet();
+
 		for (Object key : keySet) {
 			if (key != null && key.toString().toLowerCase().contains("font")) {
 				Font font = UIManager.getDefaults().getFont(key);
+
 				if (font != null) {
 					font = font.deriveFont((float) size);
 					UIManager.put(key, font);
@@ -132,9 +134,11 @@ public class ExBoxFrame extends JFrame implements ActionListener, ItemListener {
 	private Path getPathCompiled() {
 		try {
 			Path path = Paths.get(getClass().getProtectionDomain().getCodeSource().getLocation().toURI());
+
 			for (String part : getClass().getPackage().getName().split("\\.")) {
 				path = path.resolve(part);
 			}
+
 			return path;
 		} catch (URISyntaxException e) {
 			throw new RuntimeException(e);
@@ -150,11 +154,11 @@ public class ExBoxFrame extends JFrame implements ActionListener, ItemListener {
 		} catch (Exception ex) {
 			ex.printStackTrace();
 		}
+
 		Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
 		double scaleFaktor = (screenSize.getWidth() <= UHDTHRESHOLD) ? 1 : 2;
 		setFontSize((int) (11 * scaleFaktor));
-		setSize(
-				new	Dimension((int) (400 * scaleFaktor), (int) (400 * scaleFaktor)));
+		setSize(new Dimension((int) (400 * scaleFaktor), (int) (400 * scaleFaktor)));
 		setTitle("ExBox");
 		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 		initComponents();
@@ -174,14 +178,17 @@ public class ExBoxFrame extends JFrame implements ActionListener, ItemListener {
 		if (lastServer != null) {
 			command = ServerFactory.createServer(lastServer);
 		}
+
 		if (!arguments.getText().equals(history.getItemAt(0))
 				&& !arguments.getText().equals(history.getSelectedItem())) {
 			history.insertItemAt(arguments.getText(), 0);
 		}
+
 		if (command == null) {
 			error("no Server connected");
 		} else {
 			String res = command.execute(args);
+
 			if (graphicOn) {
 				graphic.setFigure(res);
 			} else {
@@ -213,17 +220,20 @@ public class ExBoxFrame extends JFrame implements ActionListener, ItemListener {
 	}
 
 	private String openFileDialog(Path startDirectory, String pattern) {
-		FileDialog	fd = new FileDialog(this, "Open");
-		if (pattern != null) fd.setFile(pattern);
-		if (startDirectory != null) fd.setDirectory(startDirectory.toString());
+		FileDialog fd = new FileDialog(this, "Open");
+		if (pattern != null)
+			fd.setFile(pattern);
+		if (startDirectory != null)
+			fd.setDirectory(startDirectory.toString());
 		fd.setVisible(true);
-		return  fd.getDirectory() + fd.getFile();
+		return fd.getDirectory() + fd.getFile();
 	}
 
 	private void testCommand(boolean retest) throws Exception {
 		if (!retest) {
 			lastTestFile = openFileDialog(getPathCompiled(), "*test.class");
 		}
+
 		if (lastTestFile == null) {
 			output.append("ERROR no Test spezified\n");
 		} else if (unitTest != null) {
@@ -236,29 +246,29 @@ public class ExBoxFrame extends JFrame implements ActionListener, ItemListener {
 		command = ServerFactory.createServer(name);
 		lastServer = name;
 		String fullClassName = command.getClass().getName();
-		String simpleClassName = fullClassName.substring(
-				fullClassName.lastIndexOf('.') + 1);
+		String simpleClassName = fullClassName.substring(fullClassName.lastIndexOf('.') + 1);
 		setTitle("ExBox connected to " + simpleClassName);
 
 	}
 
-	private void openFile()  throws Exception {
+	private void openFile() throws Exception {
 		String name = openFileDialog(null, null);
 
 		try (BufferedReader br = new BufferedReader(
-				new InputStreamReader(new FileInputStream(name), STANDARDENCODING)))
-		{
+				new InputStreamReader(new FileInputStream(name), STANDARDENCODING))) {
 			StringBuilder b = new StringBuilder();
 			String line;
+
 			while ((line = br.readLine()) != null) {
 				b.append(line);
 				b.append('\n');
 			}
+
 			execute(b.toString());
 		}
 	}
 
-	public void	itemStateChanged(ItemEvent e) {
+	public void itemStateChanged(ItemEvent e) {
 		try {
 			arguments.setText((String) e.getItem());
 			execute(arguments.getText());
@@ -267,7 +277,7 @@ public class ExBoxFrame extends JFrame implements ActionListener, ItemListener {
 		}
 	}
 
-	public void	actionPerformed(ActionEvent	e) {
+	public void actionPerformed(ActionEvent e) {
 		try {
 			if ((e.getSource() == arguments) || (e.getSource() == enter)) {
 				execute(arguments.getText());
@@ -293,4 +303,4 @@ public class ExBoxFrame extends JFrame implements ActionListener, ItemListener {
 			error(ex.toString());
 		}
 	}
-}
+}

app/src/main/java/ch/nuth/zhaw/exbox/ExBoxJUnit.java

@@ -19,9 +19,7 @@ public class ExBoxJUnit implements CommandExecutor {
     public String execute(String testFile) throws Exception {
         final List<String> successfulTests = new LinkedList<>();
         final List<TestFailure> failedResults = new LinkedList<>();
-
         StringBuilder output = new StringBuilder();
-
         output.append("\nRUN TESTS ").append(new File(testFile).getName().split("\\.")[0]).append("\n");
 
         LauncherDiscoveryRequest request = LauncherDiscoveryRequestBuilder.request()
@@ -30,6 +28,7 @@ public class ExBoxJUnit implements CommandExecutor {
 
         Launcher launcher = LauncherFactory.create();
         launcher.discover(request);
+
         launcher.registerTestExecutionListeners(new TestExecutionListener() {
             @Override
             public void executionFinished(TestIdentifier testIdentifier, TestExecutionResult testExecutionResult) {
@@ -45,21 +44,27 @@ public class ExBoxJUnit implements CommandExecutor {
                 }
             }
         });
+
         launcher.execute(request);
 
         for (String testName : successfulTests) {
             output.append(testName).append(": OK\n");
         }
+
         for (TestFailure result : failedResults) {
             output.append(result.getName()).append(": ERROR\n");
             String error = result.errorString();
+
             if (!error.isEmpty()) {
                 output.append(error).append("\n");
             }
         }
+
         boolean wasSuccessful = failedResults.isEmpty();
+
         output.append("TESTS ").append(wasSuccessful ? "PASSED" : "FAILED").append(": ")
                 .append(wasSuccessful ? "OK \u263a" : failedResults.size() + " ERRORS").append("\n");
+
         return output.toString();
     }
 
@@ -80,8 +85,9 @@ public class ExBoxJUnit implements CommandExecutor {
             if (throwable == null) {
                 return "";
             }
+
             try (StringWriter stringWriter = new StringWriter();
-                 PrintWriter printWriter = new PrintWriter(stringWriter)) {
+                    PrintWriter printWriter = new PrintWriter(stringWriter)) {
                 throwable.printStackTrace(printWriter);
                 return stringWriter.toString();
             } catch (IOException e) {

app/src/main/java/ch/nuth/zhaw/exbox/GraphicPanel.java

@@ -19,6 +19,7 @@ public class GraphicPanel extends JPanel {
 		int iy0 = (int) (h * y);
 		int ix1 = (int) (w * (x + width));
 		int iy1 = (int) (h * (y + height));
+
 		if (style.equals("draw")) {
 			g.drawRect(ix0, h - iy1, ix1 - ix0, iy1 - iy0);
 		} else {
@@ -32,8 +33,10 @@ public class GraphicPanel extends JPanel {
 			int h = getHeight();
 			g.setColor(Color.black);
 			StringTokenizer tok = new StringTokenizer(figure, " <>=/,\"\n");
+
 			while (tok.hasMoreTokens()) {
 				String fig = tok.nextToken();
+
 				if (fig.equals("line")) {
 					tok.nextToken();
 					double x1 = Double.parseDouble(tok.nextToken());
@@ -43,6 +46,7 @@ public class GraphicPanel extends JPanel {
 					double x2 = Double.parseDouble(tok.nextToken());
 					tok.nextToken();
 					double y2 = Double.parseDouble(tok.nextToken());
+
 					g.drawLine((int) (x1 * w), h - (int) (y1 * h),
 							(int) (x2 * w), h - (int) (y2 * h));
 				} else if (fig.equals("rect")) {

app/src/main/java/ch/nuth/zhaw/exbox/HanoiServer.java

@@ -0,0 +1,25 @@
+package ch.nuth.zhaw.exbox;
+
+/**
+ * Provides the functionality to determine the solution of a hanoi puzzle.
+ */
+public class HanoiServer implements CommandExecutor {
+    @Override
+    public String execute(String command) throws Exception {
+        int count = Integer.parseInt(command);
+        return moveDisks(count, 'A', 'B', 'C') + System.lineSeparator();
+    }
+
+    public String moveDisks(int count, char sourcePole, char restPole, char destinationPole) {
+        String start = "";
+        String mid = String.format("Move disk %d from %s to %s", count, sourcePole, destinationPole);
+        String end = "";
+
+        if (count > 1) {
+            start = moveDisks(count - 1, sourcePole, destinationPole, restPole);
+            end = moveDisks(count - 1, restPole, sourcePole, destinationPole);
+        }
+
+        return String.join(System.lineSeparator(), start, mid, end).trim();
+    }
+}

app/src/main/java/ch/nuth/zhaw/exbox/HilbertServer.java

@@ -0,0 +1,40 @@
+package ch.nuth.zhaw.exbox;
+
+/**
+ * Provides the functionality to draw hilbert curves.
+ */
+public class HilbertServer implements CommandExecutor {
+    @Override
+    public String execute(String command) {
+        int depth = Integer.parseInt(command);
+        Turtle turtle = Turtle.instance();
+        double dist = 0.8 / (Math.pow(2, depth + 1) - 1);
+        turtle.reset(0.1, 0.1);
+        hilbert(turtle, depth, dist, -90);
+        return turtle.getTrace();
+    }
+
+    private void hilbert(Turtle turtle, int depth, double dist, double angle) {
+        if (depth > 0) {
+            turtle.turn(-angle);
+            hilbert(turtle, depth - 1, dist, -angle);
+            turtle.move(dist);
+            turtle.turn(angle);
+            hilbert(turtle, depth - 1, dist, angle);
+            turtle.move(dist);
+            hilbert(turtle, depth - 1, dist, angle);
+            turtle.turn(angle);
+            turtle.move(dist);
+            hilbert(turtle, depth - 1, dist, -angle);
+            turtle.turn(-angle);
+        } else {
+            turtle.turn(-angle);
+            turtle.move(dist);
+            turtle.turn(angle);
+            turtle.move(dist);
+            turtle.turn(angle);
+            turtle.move(dist);
+            turtle.turn(-angle);
+        }
+    }
+}

app/src/main/java/ch/nuth/zhaw/exbox/LCMServer.java

@@ -17,8 +17,7 @@ public class LCMServer implements CommandExecutor {
             int y = Integer.parseInt(matcher.group(2));
             int result = leastCommonMultiple(x, y);
             return "Das Resultat ist %d\n".formatted(result);
-        }
-        else {
+        } else {
             throw new Exception("Der angegebene Befehl \"%s\" ist ungültig!\n".formatted(command));
         }
     }
@@ -31,7 +30,7 @@ public class LCMServer implements CommandExecutor {
         while (y != 0) {
             x %= y;
             x ^= y;
-            y ^=x;
+            y ^= x;
             x ^= y;
         }
 

app/src/main/java/ch/nuth/zhaw/exbox/ListStack.java

@@ -12,8 +12,7 @@ public class ListStack implements Stack {
             if (innerList.add(x)) {
                 return;
             }
-        }
-        catch (Exception e) {
+        } catch (Exception e) {
             throw new StackOverflowError();
         }
     }
@@ -53,5 +52,5 @@ public class ListStack implements Stack {
     public boolean isFull() {
         return innerList.size() == Integer.MIN_VALUE;
     }
-    
+
 }

app/src/main/java/ch/nuth/zhaw/exbox/MyList.java

@@ -192,10 +192,10 @@ public class MyList extends AbstractList<Object> {
      * Inserts the specified `item` after the specified `node`.
      *
      * @param node
-     * The node to insert the `item` after.
+     *             The node to insert the `item` after.
      *
      * @param item
-     * The item to insert.
+     *             The item to insert.
      */
     protected void insertAfter(IListNode node, Object item) {
         IListNode newNode = new ListNode(item, node.getNextNode(), node);

app/src/main/java/ch/nuth/zhaw/exbox/RankingListServer.java

@@ -4,6 +4,7 @@ import java.io.BufferedReader;
 import java.io.StringReader;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.Collectors;
 
 public class RankingListServer implements CommandExecutor {
     /**
@@ -22,10 +23,10 @@ public class RankingListServer implements CommandExecutor {
                     String[] fields = currentLine.split(Delimiter);
 
                     result.add(
-                        new Competitor(
-                            0,
-                            fields[0],
-                            fields[1]));
+                            new Competitor(
+                                    0,
+                                    fields[0],
+                                    fields[1]));
                 }
 
                 return result;
@@ -39,7 +40,7 @@ public class RankingListServer implements CommandExecutor {
     }
 
     public String createSortedText(List<Competitor> competitorList) {
-        List<Competitor> competitors = competitorList.stream().sorted().toList();
+        List<Competitor> competitors = competitorList.stream().sorted().collect(Collectors.toList());
         String previousTime = null;
         int previousRank = 1;
 
@@ -55,14 +56,16 @@ public class RankingListServer implements CommandExecutor {
         }
 
         return String.join(
-            System.lineSeparator(),
-            competitors.stream().map((competitor) -> competitor.toString()).toList());
+                System.lineSeparator(),
+                competitors.stream().map(
+                        (competitor) -> competitor.toString()).collect(Collectors.toList()));
     }
 
     public String createNameList(List<Competitor> competitorList) {
         return String.join(
-            System.lineSeparator(),
-            competitorList.stream().sorted(new AlphaComparatorCompetitor()).map((competitor) -> competitor.toString()).toList());
+                System.lineSeparator(),
+                competitorList.stream().sorted(new AlphaComparatorCompetitor()).map(
+                        (competitor) -> competitor.toString()).collect(Collectors.toList()));
     }
 
     public String execute(String rankingList) {

app/src/main/java/ch/nuth/zhaw/exbox/ServerFactory.java

@@ -16,7 +16,8 @@ class MyClassLoader extends ClassLoader {
 
     /**
      * @param name filename of class
-     * return content of file as array of bytes; if file does not exist return null
+     *             return content of file as array of bytes; if file does not exist
+     *             return null
      */
     private byte[] getBytes(String name) {
         try {
@@ -38,15 +39,19 @@ class MyClassLoader extends ClassLoader {
         System.out.println("load:" + name + " " + resolve);
         Class<?> clazz;
         byte[] classData = getBytes(name);
+
         if (classData != null) {
             clazz = defineClass(null, classData, 0, classData.length);
+
             path = name.substring(0,
                     name.length() - clazz.getName().length() - ".class".length());
+
             return clazz;
         }
         if (!resolve) {
             classData = getBytes(
                     path + name.replace(".", File.separator) + ".class");
+
             if (classData != null) {
                 return defineClass(null, classData, 0, classData.length);
             }
@@ -67,10 +72,11 @@ public class ServerFactory {
     public static Class<?> loadClass(String name) throws Exception {
         MyClassLoader myClassLoader = new MyClassLoader(
                 MyClassLoader.class.getClassLoader());
+
         return myClassLoader.loadClass(name, true);
     }
 
     public static CommandExecutor createServer(String name) throws Exception {
-        return (CommandExecutor) loadClass(name).getConstructor(new Class[]{}).newInstance();
+        return (CommandExecutor) loadClass(name).getConstructor(new Class[] {}).newInstance();
     }
-}
+}

app/src/main/java/ch/nuth/zhaw/exbox/SnowflakeServer.java

@@ -0,0 +1,39 @@
+package ch.nuth.zhaw.exbox;
+
+/**
+ * Provides the functionality to draw a snowflake.
+ */
+public class SnowflakeServer implements CommandExecutor {
+    @Override
+    public String execute(String command) {
+        int recursionLevel = Integer.parseInt(command);
+        Turtle turtle = Turtle.instance();
+        drawSnowflake(turtle, recursionLevel);
+        return turtle.getTrace();
+    }
+
+    public void drawSnowflake(Turtle turtle, int recursionLevel) {
+        turtle.reset(0.1, 0.266);
+        turtle.turn(60);
+
+        for (int i = 0; i < 3; i++) {
+            drawLine(turtle, recursionLevel, 0.8);
+            turtle.turn(-120);
+        }
+    }
+
+    public void drawLine(Turtle turtle, int recursionLevel, double destination) {
+        if (recursionLevel == 0) {
+            turtle.move(destination);
+        } else {
+            double distance = destination / 3;
+
+            for (int i = 0; i < 3; i++) {
+                drawLine(turtle, recursionLevel - 1, distance);
+                turtle.turn(i % 2 == 0 ? 60 : -120);
+            }
+
+            drawLine(turtle, recursionLevel - 1, distance);
+        }
+    }
+}

app/src/main/java/ch/nuth/zhaw/exbox/Stack.java

@@ -46,4 +46,4 @@ public interface Stack {
      * @return Gibt true zurück, falls der Stack voll ist.
      */
     boolean isFull();
-}
+}

app/src/main/java/ch/nuth/zhaw/exbox/TestGraphicServer.java

@@ -0,0 +1,17 @@
+package ch.nuth.zhaw.exbox;
+
+public class TestGraphicServer implements CommandExecutor {
+    String figure = "<line x1=\"0.1\" y1 = \"0.8\" x2=\"0.9\" y2 = \"0.8\" />\n" +
+            "<line x1=\"0.2\" y1 = \"0.4\" x2=\"0.2\" y2 = \"0.8\" />\n" +
+            "<line x1=\"0.3\" y1 = \"0.4\" x2=\"0.3\" y2 = \"0.8\" />\n" +
+            "<line x1=\"0.3\" y1 = \"0.4\" x2=\"0.7\" y2 = \"0.4\" />\n" +
+            "<line x1=\"0.3\" y1 = \"0.6\" x2=\"0.4\" y2 = \"0.6\" />\n" +
+            "<line x1=\"0.5\" y1 = \"0.8\" x2=\"0.5\" y2 = \"0.6\" />\n" +
+            "<line x1=\"0.5\" y1 = \"0.6\" x2=\"0.7\" y2 = \"0.6\" />\n" +
+            "<line x1=\"0.7\" y1 = \"0.6\" x2=\"0.7\" y2 = \"0.4\" />\n" +
+            "<line x1=\"0.8\" y1 = \"0.4\" x2=\"0.8\" y2 = \"0.8\" />\n";
+
+    public String execute(String command) {
+        return figure;
+    }
+}

app/src/main/java/ch/nuth/zhaw/exbox/Turtle.java

@@ -0,0 +1,63 @@
+package ch.nuth.zhaw.exbox;
+
+public class Turtle {
+    private static StringBuffer b;
+    private static double x, y;
+    private static double angle;
+    private static Turtle theTurtle;
+
+    public static Turtle instance() {
+        if (theTurtle == null) {
+            theTurtle = new Turtle();
+        }
+
+        return theTurtle;
+    }
+
+    public Turtle() {
+        this(0, 0);
+    }
+
+    public Turtle(double x, double y) {
+        reset(x, y);
+        theTurtle = this;
+    }
+
+    public void reset(double x, double y) {
+        b = new StringBuffer();
+        Turtle.x = x;
+        Turtle.y = y;
+        angle = 0;
+    }
+
+    public void clear() {
+        reset(0, 0);
+    }
+
+    public String getTrace() {
+        return b.toString();
+    }
+
+    private double round(double d) {
+        return Math.round(d * 10000) / 10000.0;
+    }
+
+    public void move(double dist) {
+        b.append("<line x1=\"");
+        b.append(Double.toString(round(x)));
+        b.append("\" y1=\"");
+        b.append(Double.toString(round(y)));
+        b.append("\" ");
+        x += Math.cos(angle) * dist;
+        y += Math.sin(angle) * dist;
+        b.append("x2=\"");
+        b.append(Double.toString(round(x)));
+        b.append("\" y2=\"");
+        b.append(Double.toString(round(y)));
+        b.append("\"/>\n");
+    }
+
+    public void turn(double turnAngle) {
+        angle += turnAngle * Math.PI / 180;
+    }
+}

app/src/test/java/ch/nuth/zhaw/exbox/ADS2_3_test.java

@@ -75,9 +75,11 @@ public class ADS2_3_test {
     public void testMixed() {
         list.clear();
         List<Character> list2 = new LinkedList<>();
+
         for (int i = 0; i < 100; i++) {
             Character c = (char) ('A' + (Math.random() * 26));
             int op = (int) (Math.random() * 2);
+
             switch (op) {
                 case 0:
                     list.add(c);
@@ -89,7 +91,9 @@ public class ADS2_3_test {
                     break;
             }
         }
+
         assertEquals(list2.size(), list.size());
+
         for (int i = 0; i < list.size(); i++) {
             char c1 = (char) list.get(i);
             char c2 = (char) list2.get(i);

app/src/test/java/ch/nuth/zhaw/exbox/ADS2_4_test.java

@@ -55,9 +55,11 @@ public class ADS2_4_test {
     @Test
     public void testMixed() {
         List<Character> list2 = new LinkedList<>();
+
         for (int i = 0; i < 100; i++) {
-            Character c = (char) ('A' + (Math.random()*26));
-            int op = (int)(Math.random()*2);
+            Character c = (char) ('A' + (Math.random() * 26));
+            int op = (int) (Math.random() * 2);
+
             switch (op) {
                 case 0:
                     list.add(c);
@@ -69,11 +71,13 @@ public class ADS2_4_test {
                     break;
             }
         }
+
         Collections.sort(list2);
         assertEquals(list2.size(), list.size());
+
         for (int i = 0; i < list.size(); i++) {
-            char c1 = (char)list.get(i);
-            char c2 = (char)list2.get(i);
+            char c1 = (char) list.get(i);
+            char c2 = (char) list2.get(i);
             assertEquals(c1, c2);
         }
     }

app/src/test/java/ch/nuth/zhaw/exbox/ADS3_1_test.java

@@ -18,17 +18,17 @@ public class ADS3_1_test {
 
     @Test
     public void testEquals() {
-        assertTrue(c3.equals(c3), c3.getTime() + " == "+c3.getTime());
-        assertTrue(!c3.equals(c2), c3.getTime() + " != "+c2.getTime());
+        assertTrue(c3.equals(c3), c3.getTime() + " == " + c3.getTime());
+        assertTrue(!c3.equals(c2), c3.getTime() + " != " + c2.getTime());
         assertTrue(!c3.equals(null), "equals(null)");
         assertTrue(!c3.equals(new Object()), "equals(new Object())");
     }
 
     @Test
     public void testCompare() {
-        assertTrue(c1.compareTo(c2) > 0, c1.getName() +" "+c1.getTime() + " > "+c2.getTime());
-        assertTrue(c2.compareTo(c1) < 0, c2.getName() +" "+c2.getTime() + " < "+c1.getTime());
-        assertTrue(c3.compareTo(c3) == 0, c3.getName() +" "+c3.getTime() + " == "+c3.getTime());
-        assertTrue(c4.compareTo(c2) < 0, c4.getName() +" "+c4.getTime() + " < "+c2.getTime());
+        assertTrue(c1.compareTo(c2) > 0, c1.getName() + " " + c1.getTime() + " > " + c2.getTime());
+        assertTrue(c2.compareTo(c1) < 0, c2.getName() + " " + c2.getTime() + " < " + c1.getTime());
+        assertTrue(c3.compareTo(c3) == 0, c3.getName() + " " + c3.getTime() + " == " + c3.getTime());
+        assertTrue(c4.compareTo(c2) < 0, c4.getName() + " " + c4.getTime() + " < " + c2.getTime());
     }
 }

app/src/test/java/ch/nuth/zhaw/exbox/ADS3_2_test.java

@@ -18,7 +18,7 @@ public class ADS3_2_test {
         for (String line : lines) {
             String name = line.split(";")[0];
             String time = line.split(";")[1];
-            competitorList.add(new Competitor(0, name,  time));
+            competitorList.add(new Competitor(0, name, time));
         }
         return competitorList;
     }
@@ -35,6 +35,7 @@ public class ADS3_2_test {
                 "Oliver Ruben;02:32:12\n" +
                 "Elmer Beat;02:33:53\n" +
                 "Kuehni Martin;02:33:36\n";
+
         rankGood = createList(rangliste);
         rankTest = new RankingListServer().createList(rangliste);
     }
@@ -42,8 +43,9 @@ public class ADS3_2_test {
     @Test
     public void testCreateList() {
         assertEquals(rankGood.size(), rankTest.size(), "length");
-        for (int i = 0; i < rankGood.size();i++) {
-            assertEquals(rankGood.get(i).toString(), rankTest.get(i).toString(), "rangliste["+i+"]");
+
+        for (int i = 0; i < rankGood.size(); i++) {
+            assertEquals(rankGood.get(i).toString(), rankTest.get(i).toString(), "rangliste[" + i + "]");
         }
     }
 }

app/src/test/java/ch/nuth/zhaw/exbox/ADS3_3_test.java

@@ -18,11 +18,13 @@ public class ADS3_3_test {
     public List<Competitor> createList(String rankingText) {
         List<Competitor> competitorList = new LinkedList<>();
         String[] lines = rankingText.split("\n");
+
         for (String line : lines) {
             String name = line.split(";")[0];
             String time = line.split(";")[1];
-            competitorList.add(new Competitor(0, name,  time));
+            competitorList.add(new Competitor(0, name, time));
         }
+
         return competitorList;
     }
 
@@ -30,10 +32,12 @@ public class ADS3_3_test {
         Collections.sort(competitorList);
         int rank = 1;
         StringBuilder sb = new StringBuilder();
+
         for (Competitor c : competitorList) {
             c.setRank(rank++);
             sb.append(c).append("\n");
         }
+
         return sb.toString();
     }
 
@@ -49,11 +53,13 @@ public class ADS3_3_test {
                 "Oliver Ruben;02:32:12\n" +
                 "Elmer Beat;02:33:53\n" +
                 "Kuehni Martin;02:33:36\n";
+
         rankGood = createList(rangliste);
         textGood = createSortedText(rankGood);
         rankTest = new RankingListServer().createList(rangliste);
         textTest = new RankingListServer().createSortedText(rankTest);
     }
+
     private String clean(String s) {
         return s.trim();
     }
@@ -63,8 +69,9 @@ public class ADS3_3_test {
         String[] good = textGood.split("\n");
         String[] test = textTest.split("\n");
         assertEquals(good.length, test.length, "length");
-        for (int i = 0; i < good.length;i++) {
-            assertEquals(clean(good[i]), clean(test[i]), "rangliste["+i+"]");
+
+        for (int i = 0; i < good.length; i++) {
+            assertEquals(clean(good[i]), clean(test[i]), "rangliste[" + i + "]");
         }
     }
 }

app/src/test/java/ch/nuth/zhaw/exbox/ADS3_4_test.java

@@ -17,35 +17,39 @@ public class ADS3_4_test {
     public List<Competitor> createList(String rankingText) {
         List<Competitor> competitorList = new LinkedList<>();
         String[] lines = rankingText.split("\n");
+
         for (String line : lines) {
             String name = line.split(";")[0];
             String time = line.split(";")[1];
-            competitorList.add(new Competitor(0, name,  time));
+            competitorList.add(new Competitor(0, name, time));
         }
+        
         return competitorList;
     }
 
     public String createSortedText(List<Competitor> competitorList) {
         StringBuilder sb = new StringBuilder();
+
         for (Competitor c : competitorList) {
             sb.append(c).append("\n");
         }
+
         return sb.toString();
     }
 
     @BeforeEach
     public void setUp() {
-        String ranglisteOrdered =
-                "Ancay Tarcis;02:20:02\n" +
-                        "Elmer Beat;02:33:53\n" +
-                        "Kiptum Daniel;02:11:31\n" +
-                        "Kreibuhl Christian;02:21:47\n" +
-                        "Kuehni Martin;02:33:36\n" +
-                        "Marti Adrian;02:30:09\n" +
-                        "Menzi Christoph;02:27:26\n" +
-                        "Mueller Stefan;02:31:14\n" +
-                        "Oliver Ruben;02:32:12\n" +
-                        "Ott Michael;02:33:48\n";
+        String ranglisteOrdered = "Ancay Tarcis;02:20:02\n" +
+                "Elmer Beat;02:33:53\n" +
+                "Kiptum Daniel;02:11:31\n" +
+                "Kreibuhl Christian;02:21:47\n" +
+                "Kuehni Martin;02:33:36\n" +
+                "Marti Adrian;02:30:09\n" +
+                "Menzi Christoph;02:27:26\n" +
+                "Mueller Stefan;02:31:14\n" +
+                "Oliver Ruben;02:32:12\n" +
+                "Ott Michael;02:33:48\n";
+
         String ranglisteUnordered = "Mueller Stefan;02:31:14\n" +
                 "Marti Adrian;02:30:09\n" +
                 "Kiptum Daniel;02:11:31\n" +
@@ -56,6 +60,7 @@ public class ADS3_4_test {
                 "Oliver Ruben;02:32:12\n" +
                 "Elmer Beat;02:33:53\n" +
                 "Kuehni Martin;02:33:36\n";
+
         rankGood = createList(ranglisteOrdered);
         textGood = createSortedText(rankGood);
         rankTest = createList(ranglisteUnordered);
@@ -71,8 +76,9 @@ public class ADS3_4_test {
         String[] good = textGood.split("\n");
         String[] test = textTest.split("\n");
         assertEquals(good.length, test.length, "length");
-        for (int i = 0; i < good.length;i++) {
-            assertEquals(clean(good[i]), clean(test[i]), "rangliste["+i+"]");
+
+        for (int i = 0; i < good.length; i++) {
+            assertEquals(clean(good[i]), clean(test[i]), "rangliste[" + i + "]");
         }
     }
 }

app/src/test/java/ch/nuth/zhaw/exbox/ADS4_1_test.java

@@ -0,0 +1,101 @@
+package ch.nuth.zhaw.exbox;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.StringTokenizer;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class ADS4_1_test {
+    SnowflakeServer sf;
+    Turtle turtle;
+    final double EPS = 1;
+
+    double angle(double x1, double y1, double x2, double y2,
+            double x3, double y3, double x4, double y4) {
+        double ax, ay, bx, by;
+        // https://www.frustfrei-lernen.de/mathematik/schnittwinkel-zweier-geraden.html
+        ax = x2 - x1;
+        ay = y2 - y1;
+        bx = x4 - x3;
+        by = y4 - y3;
+
+        double a = Math.acos(
+                (ax * bx + ay * by)
+                        / (Math.sqrt(ax * ax + ay * ay) * Math.sqrt(bx * bx + by * by)));
+
+        return a / Math.PI * 180;
+    }
+
+    double angle(String line1, String line2) {
+        StringTokenizer tok = new StringTokenizer(line1, " <>=/,\"\n");
+        tok.nextToken(); // line
+        tok.nextToken();
+        double x1 = Double.parseDouble(tok.nextToken());
+        tok.nextToken();
+        double y1 = Double.parseDouble(tok.nextToken());
+        tok.nextToken();
+        double x2 = Double.parseDouble(tok.nextToken());
+        tok.nextToken();
+        double y2 = Double.parseDouble(tok.nextToken());
+        tok = new StringTokenizer(line2, " <>=/,\"\n");
+        tok.nextToken(); // line
+        tok.nextToken();
+        double x3 = Double.parseDouble(tok.nextToken());
+        tok.nextToken();
+        double y3 = Double.parseDouble(tok.nextToken());
+        tok.nextToken();
+        double x4 = Double.parseDouble(tok.nextToken());
+        tok.nextToken();
+        double y4 = Double.parseDouble(tok.nextToken());
+        return angle(x1, y1, x2, y2, x3, y3, x4, y4);
+    }
+
+    @BeforeEach
+    public void setUp() {
+        sf = new SnowflakeServer();
+        turtle = new Turtle();
+    }
+
+    void snowflake(int stufe, double dist) {
+        if (stufe == 0) {
+            turtle.move(dist);
+        } else {
+            stufe--;
+            dist = dist / 3;
+            snowflake(stufe, dist);
+            turtle.turn(60);
+            snowflake(stufe, dist);
+            turtle.turn(-120);
+            snowflake(stufe, dist);
+            turtle.turn(60);
+            snowflake(stufe, dist);
+        }
+    }
+
+    @Test
+    public void testCountEdges() {
+        turtle.clear();
+        snowflake(3, 0.7);
+        String[] linesGood = Turtle.instance().getTrace().split("\n");
+        turtle.clear();
+        sf.execute("3");
+        String[] lines = Turtle.instance().getTrace().split("\n");
+        assertEquals(linesGood.length * 3, lines.length, "Count Edges");
+    }
+
+    @Test
+    public void testAngles() {
+        turtle.clear();
+        snowflake(3, 0.7);
+        String[] linesGood = Turtle.instance().getTrace().split("\n");
+        turtle.clear();
+        sf.execute("3");
+        String[] lines = Turtle.instance().getTrace().split("\n");
+
+        for (int i = 0; i < linesGood.length - 1; i++) {
+            assertEquals(angle(linesGood[i], linesGood[i + 1]), angle(lines[i], lines[i + 1]), EPS, "Angle " + i);
+        }
+    }
+}

app/src/test/java/ch/nuth/zhaw/exbox/ADS4_2_test.java

@@ -0,0 +1,101 @@
+package ch.nuth.zhaw.exbox;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.BeforeEach;
+
+import java.util.StringTokenizer;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class ADS4_2_test {
+    HilbertServer hlb;
+    Turtle turtle;
+    final double EPS = 1E-1;
+
+    double angle(double x1, double y1, double x2, double y2,
+            double x3, double y3, double x4, double y4) {
+        double ax, ay, bx, by;
+        // https://www.frustfrei-lernen.de/mathematik/schnittwinkel-zweier-geraden.html
+        ax = x2 - x1;
+        ay = y2 - y1;
+        bx = x4 - x3;
+        by = y4 - y3;
+
+        double a = Math.acos(
+                (ax * bx + ay * by)
+                        / (Math.sqrt(ax * ax + ay * ay) * Math.sqrt(bx * bx + by * by)));
+
+        return a / Math.PI * 180;
+    }
+
+    double angle(String line1, String line2) {
+        StringTokenizer tok = new StringTokenizer(line1, " <>=/,\"\n");
+        tok.nextToken(); // line
+        tok.nextToken();
+        double x1 = Double.parseDouble(tok.nextToken());
+        tok.nextToken();
+        double y1 = Double.parseDouble(tok.nextToken());
+        tok.nextToken();
+        double x2 = Double.parseDouble(tok.nextToken());
+        tok.nextToken();
+        double y2 = Double.parseDouble(tok.nextToken());
+        tok = new StringTokenizer(line2, " <>=/,\"\n");
+        tok.nextToken(); // line
+        tok.nextToken();
+        double x3 = Double.parseDouble(tok.nextToken());
+        tok.nextToken();
+        double y3 = Double.parseDouble(tok.nextToken());
+        tok.nextToken();
+        double x4 = Double.parseDouble(tok.nextToken());
+        tok.nextToken();
+        double y4 = Double.parseDouble(tok.nextToken());
+        return angle(x1, y1, x2, y2, x3, y3, x4, y4);
+    }
+
+    @BeforeEach
+    public void setUp() {
+        hlb = new HilbertServer();
+        turtle = new Turtle();
+    }
+
+    private void hilbert(int depth, double dist, double angle) {
+        if (depth >= 0) {
+            turtle.turn(-angle);
+            hilbert(depth - 1, dist, -angle);
+            turtle.move(dist);
+            turtle.turn(angle);
+            hilbert(depth - 1, dist, angle);
+            turtle.move(dist);
+            hilbert(depth - 1, dist, angle);
+            turtle.turn(angle);
+            turtle.move(dist);
+            hilbert(depth - 1, dist, -angle);
+            turtle.turn(-angle);
+        }
+    }
+
+    @Test
+    public void testCountEdges() {
+        turtle.clear();
+        hilbert(3, .4, -90);
+        String[] linesGood = Turtle.instance().getTrace().split("\n");
+        turtle.clear();
+        hlb.execute("3");
+        String[] lines = Turtle.instance().getTrace().split("\n");
+        assertEquals(linesGood.length, lines.length, "Count Edges");
+    }
+
+    @Test
+    public void testAngles() {
+        turtle.clear();
+        hilbert(3, .4, -90);
+        String[] linesGood = Turtle.instance().getTrace().split("\n");
+        turtle.clear();
+        hlb.execute("3");
+        String[] lines = Turtle.instance().getTrace().split("\n");
+
+        for (int i = 0; i < linesGood.length - 1; i++) {
+            assertEquals(angle(linesGood[i], linesGood[i + 1]), angle(lines[i], lines[i + 1]), EPS, "Angle " + i);
+        }
+    }
+}