fix: EOF ends game loop (ConsoleIO returns null on EOF); settings.json excluded from save slots

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Semesterprojekt/src/main/java/thb/jeanluc/adventure/io/ConsoleIO.java

@@ -71,10 +71,11 @@ public class ConsoleIO implements GameIO {
         out.print("> ");
         out.flush();
         try {
-            String line = in.readLine();
+            // null propagates as true EOF (ends the game loop); "" stays "" (blank input re-prompts).
-            return line == null ? "" : line;
+            return in.readLine();
         } catch (IOException e) {
-            return "";
+            // Treat a stream failure as EOF so input ends cleanly rather than spinning.
+            return null;
         }
     }
 

Semesterprojekt/src/main/java/thb/jeanluc/adventure/save/SaveService.java

@@ -23,6 +23,8 @@ import java.util.stream.Stream;
 @Slf4j
 public class SaveService {
 
+    private static final String SETTINGS_FILENAME = "settings.json";
+
     private final Path dir;
     private final ObjectMapper mapper = new ObjectMapper();
 
@@ -38,7 +40,11 @@ public class SaveService {
     /** Slug used for the on-disk filename of a slot name. */
     public static String slug(String slotName) {
         String s = slotName.trim().toLowerCase(Locale.ROOT).replaceAll("[^a-z0-9_-]+", "_");
-        return s.isBlank() ? "save" : s;
+        if (s.isBlank()) {
+            return "save";
+        }
+        // Never let a user-named save collide with the settings file.
+        return s.equals("settings") ? "settings_" : s;
     }
 
     /** Writes the session to {@code <slug>.json} atomically. */
@@ -71,7 +77,10 @@ public class SaveService {
         }
         List<SaveSlotInfo> out = new ArrayList<>();
         try (Stream<Path> files = Files.list(dir)) {
-            for (Path f : files.filter(p -> p.toString().endsWith(".json")).toList()) {
+            for (Path f : files
+                    .filter(p -> p.toString().endsWith(".json"))
+                    .filter(p -> !p.getFileName().toString().equals(SETTINGS_FILENAME))
+                    .toList()) {
                 try {
                     SaveData d = mapper.readValue(f.toFile(), SaveData.class);
                     String slug = f.getFileName().toString().replaceFirst("\\.json$", "");

Semesterprojekt/src/test/java/thb/jeanluc/adventure/io/ConsoleIORenderTest.java

@@ -50,6 +50,25 @@ class ConsoleIORenderTest {
         assertThat(out).contains("Kitchen").contains("turn 7").contains("light: off");
     }
 
+    @Test
+    void readLine_returnsNullOnEof() {
+        ByteArrayOutputStream sink = new ByteArrayOutputStream();
+        PrintStream ps = new PrintStream(sink, true, StandardCharsets.UTF_8);
+        ConsoleIO io = new ConsoleIO(new BufferedReader(new StringReader("")), ps,
+                ConsoleIO.ColorMode.OFF, ConsoleIO.GlyphMode.UNICODE);
+        assertThat(io.readLine()).isNull();
+    }
+
+    @Test
+    void readLine_returnsEmptyStringForBlankLineThenNullAtEof() {
+        ByteArrayOutputStream sink = new ByteArrayOutputStream();
+        PrintStream ps = new PrintStream(sink, true, StandardCharsets.UTF_8);
+        ConsoleIO io = new ConsoleIO(new BufferedReader(new StringReader("\n")), ps,
+                ConsoleIO.ColorMode.OFF, ConsoleIO.GlyphMode.UNICODE);
+        assertThat(io.readLine()).isEqualTo(""); // blank interactive line, re-prompt
+        assertThat(io.readLine()).isNull();      // stream now exhausted → EOF
+    }
+
     @Test
     void asciiGlyphMode_usesPlusDashFrame() {
         ByteArrayOutputStream sink = new ByteArrayOutputStream();

Semesterprojekt/src/test/java/thb/jeanluc/adventure/save/SaveServiceTest.java

@@ -55,6 +55,23 @@ class SaveServiceTest {
         assertThat(new SaveService(dir).list()).isEmpty();
     }
 
+    @Test
+    void listExcludesSettingsFile(@TempDir Path dir) throws Exception {
+        SaveService svc = new SaveService(dir);
+        GameSession s = freshSession("Real Save");
+        svc.save(s);
+        Files.writeString(dir.resolve("settings.json"), "{\"color\":\"on\"}");
+
+        List<SaveSlotInfo> slots = svc.list();
+        assertThat(slots).hasSize(1);
+        assertThat(slots.getFirst().slotName()).isEqualTo("Real Save");
+    }
+
+    @Test
+    void slugForSettingsDoesNotCollideWithSettingsFile() {
+        assertThat(SaveService.slug("settings")).isNotEqualTo("settings");
+    }
+
     @Test
     void loadCorruptFileThrowsSaveException(@TempDir Path dir) throws Exception {
         Files.writeString(dir.resolve("bad.json"), "{ not json");