feat(command): accept German command and direction aliases

The assignment's examples are German ("Gehe nach Norden", "Nimm Brief",
"Lies Brief", "Benutze Schaufel") but every verb was English-only, so none of
them parsed.

- Register German aliases alongside the English ones (gehe, nimm, lies, benutze,
  lege, gib, rede, schau, karte, inventar, hilfe, beenden)
- Direction.fromString accepts norden/sueden/süden/osten/westen and the n/s/e/w
  shorthands; YAML exits keep the canonical English names
- Treat "nach", "den", "die", "das" as filler words so "Gehe nach Norden" parses

Semesterprojekt/src/main/java/thb/jeanluc/adventure/App.java

@@ -47,10 +47,15 @@ import java.util.List;
 @Slf4j
 public final class App {
 
+    /** Utility class; not instantiable. */
     private App() {
     }
 
-    /** Standard JVM entry point. @param args ignored */
+    /**
+     * Standard JVM entry point.
+     *
+     * @param args ignored
+     */
     public static void main(String[] args) {
         GameIO io = new ConsoleIO();
         try {
@@ -62,12 +67,22 @@ public final class App {
         }
     }
 
-    /** Runs the menu shell on the given IO until the player quits. */
+    /**
+     * Runs the menu shell on the given IO until the player quits.
+     *
+     * @param io frontend the menu and the game are rendered on
+     */
     public static void run(GameIO io) {
         run(io, new SaveService(), new SettingsStore());
     }
 
-    /** Runs the menu shell with injectable persistence (for testing). */
+    /**
+     * Runs the menu shell with injectable persistence (for testing).
+     *
+     * @param io            frontend the menu and the game are rendered on
+     * @param saves         save-slot backend
+     * @param settingsStore settings backend
+     */
     static void run(GameIO io, SaveService saves, SettingsStore settingsStore) {
         Settings settings = settingsStore.load();
         SettingsMenu.apply(settings, io);
@@ -112,27 +127,29 @@ public final class App {
             }
         });
 
+        // German aliases mirror the examples in the assignment ("Gehe nach
+        // Norden", "Nimm Brief", "Lies Brief", "Benutze Schaufel").
         CommandRegistry registry = new CommandRegistry();
-        registry.register(new GoCommand(), "go", "move", "walk");
+        registry.register(new GoCommand(), "go", "move", "walk", "gehe", "geh");
-        registry.register(new LookCommand(), "look", "l");
+        registry.register(new LookCommand(), "look", "l", "umsehen", "schau");
-        registry.register(new InventoryCommand(), "inventory", "inv", "i");
+        registry.register(new InventoryCommand(), "inventory", "inv", "i", "inventar");
-        registry.register(new TakeCommand(), "take", "pick", "get");
+        registry.register(new TakeCommand(), "take", "pick", "get", "nimm", "nehme");
-        registry.register(new DropCommand(), "drop", "put");
+        registry.register(new DropCommand(), "drop", "put", "lege", "ablegen");
-        registry.register(new UseCommand(), "use");
+        registry.register(new UseCommand(), "use", "benutze", "benutz");
-        registry.register(new ReadCommand(), "read");
+        registry.register(new ReadCommand(), "read", "lies", "lese");
-        registry.register(new ExamineCommand(), "examine", "x", "inspect");
+        registry.register(new ExamineCommand(), "examine", "x", "inspect", "untersuche");
-        registry.register(new MapCommand(), "map", "m");
+        registry.register(new MapCommand(), "map", "m", "karte");
-        registry.register(new QuestsCommand(), "quests", "log", "journal");
+        registry.register(new QuestsCommand(), "quests", "log", "journal", "aufgaben");
-        registry.register(new TalkCommand(), "talk", "speak");
+        registry.register(new TalkCommand(), "talk", "speak", "rede", "sprich");
-        registry.register(new GiveCommand(), "give");
+        registry.register(new GiveCommand(), "give", "gib");
-        registry.register(new SaveCommand(saves), "save");
+        registry.register(new SaveCommand(saves), "save", "speichern");
 
         Game game = new Game(ctx, registry, new CommandParser());
 
         MenuCommand menu = new MenuCommand(saves);
         menu.bind(game);
-        registry.register(menu, "menu", "quit", "exit");
+        registry.register(menu, "menu", "quit", "exit", "beenden");
-        registry.register(new HelpCommand(registry), "help", "?");
+        registry.register(new HelpCommand(registry), "help", "?", "hilfe");
 
         if (withTutorial) {
             Tutorial tutorial = new TutorialLoader().load();

Semesterprojekt/src/main/java/thb/jeanluc/adventure/command/CommandParser.java

@@ -16,7 +16,8 @@ public class CommandParser {
      * small — when adding more, watch out for words that might be valid
      * item ids ({@code key}, {@code lamp}, etc.).
      */
-    private static final Set<String> FILLERS = Set.of("to", "with", "at", "the", "a", "an", "on");
+    private static final Set<String> FILLERS =
+            Set.of("to", "with", "at", "the", "a", "an", "on", "nach", "den", "die", "das");
 
     /**
      * Parses an input line into a verb and its arguments.

Semesterprojekt/src/main/java/thb/jeanluc/adventure/model/Direction.java

@@ -1,5 +1,7 @@
 package thb.jeanluc.adventure.model;
 
+import java.util.Map;
+
 /**
  * Compass directions used for navigating between rooms.
  * Each direction has an opposite, which is used when describing
@@ -7,9 +9,13 @@ package thb.jeanluc.adventure.model;
  * entering the next room from the SOUTH).
  */
 public enum Direction {
+    /** Towards the top of the map; opposite of {@link #SOUTH}. */
     NORTH,
+    /** Towards the bottom of the map; opposite of {@link #NORTH}. */
     SOUTH,
+    /** Towards the right of the map; opposite of {@link #WEST}. */
     EAST,
+    /** Towards the left of the map; opposite of {@link #EAST}. */
     WEST;
 
     /**
@@ -38,13 +44,40 @@ public enum Direction {
         if (s == null) {
             throw new IllegalArgumentException("Direction must not be null");
         }
+        String key = s.trim().toLowerCase();
+        Direction alias = ALIASES.get(key);
+        if (alias != null) {
+            return alias;
+        }
         try {
-            return Direction.valueOf(s.trim().toUpperCase());
+            return Direction.valueOf(key.toUpperCase());
         } catch (IllegalArgumentException e) {
             throw new IllegalArgumentException("Unknown direction: '" + s + "'");
         }
     }
 
+    /**
+     * Alternative spellings accepted from player input: single-letter
+     * shorthands and the German direction names used in the assignment's
+     * examples ("Gehe nach Norden"). YAML exits still use the canonical
+     * English names.
+     */
+    private static final Map<String, Direction> ALIASES = Map.ofEntries(
+            Map.entry("n", NORTH),
+            Map.entry("s", SOUTH),
+            Map.entry("e", EAST),
+            Map.entry("w", WEST),
+            Map.entry("norden", NORTH),
+            Map.entry("sueden", SOUTH),
+            Map.entry("süden", SOUTH),
+            Map.entry("osten", EAST),
+            Map.entry("westen", WEST),
+            Map.entry("nord", NORTH),
+            Map.entry("sued", SOUTH),
+            Map.entry("süd", SOUTH),
+            Map.entry("ost", EAST),
+            Map.entry("west", WEST));
+
     /**
      * Returns the human-readable lowercase label, suitable for display
      * to the player (e.g. "north"). Intentionally not a toString override

Semesterprojekt/src/test/java/thb/jeanluc/adventure/command/GermanAliasTest.java

@@ -0,0 +1,47 @@
+package thb.jeanluc.adventure.command;
+
+import org.junit.jupiter.api.Test;
+import thb.jeanluc.adventure.model.Direction;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * The assignment's examples are German ("Gehe nach Norden", "Nimm Brief"), so
+ * those inputs must parse. English stays the canonical form used in YAML.
+ */
+class GermanAliasTest {
+
+    private final CommandParser parser = new CommandParser();
+
+    @Test
+    void parse_gehNachNorden_yieldsGoNorth() {
+        ParsedCommand c = parser.parse("Gehe nach Norden");
+
+        assertThat(c.verb()).isEqualTo("gehe");
+        assertThat(c.args()).containsExactly("norden");
+        assertThat(Direction.fromString(c.args().getFirst())).isEqualTo(Direction.NORTH);
+    }
+
+    @Test
+    void parse_nimmBrief_yieldsTakeWithItemArg() {
+        ParsedCommand c = parser.parse("Nimm Brief");
+
+        assertThat(c.verb()).isEqualTo("nimm");
+        assertThat(c.args()).containsExactly("brief");
+    }
+
+    @Test
+    void fromString_withGermanDirectionNames_resolves() {
+        assertThat(Direction.fromString("norden")).isEqualTo(Direction.NORTH);
+        assertThat(Direction.fromString("sueden")).isEqualTo(Direction.SOUTH);
+        assertThat(Direction.fromString("süden")).isEqualTo(Direction.SOUTH);
+        assertThat(Direction.fromString("osten")).isEqualTo(Direction.EAST);
+        assertThat(Direction.fromString("westen")).isEqualTo(Direction.WEST);
+    }
+
+    @Test
+    void fromString_withEnglishNames_stillResolves() {
+        assertThat(Direction.fromString("north")).isEqualTo(Direction.NORTH);
+        assertThat(Direction.fromString("n")).isEqualTo(Direction.NORTH);
+    }
+}