Method changeToNextCD of CDPlayer tested on CDWechselerNotSelected -> shouldThrowAnException.

src/main/java/device/cdPlayer/CDPlayer.java

@@ -154,6 +154,12 @@ public class CDPlayer implements Device {
         cdWechseler.loadOneCD(cd,index);
         System.out.println(index);
     }
+    public void changeToNextCD(){
+        if(activeSource.equals("CDDrive")){
+            throw new ChangeCDOnlyOnCDWechselerException();
+        }
+
+    }
 
     //Getters, Setters und SupportMethods
     public void setCD(CD _loadedCD) {

src/main/java/device/cdPlayer/exceptions/ChangeCDOnlyOnCDWechselerException.java

@@ -0,0 +1,7 @@
+package device.cdPlayer.exceptions;
+
+public class ChangeCDOnlyOnCDWechselerException extends RuntimeException{
+    public ChangeCDOnlyOnCDWechselerException(){
+        super("Change to next CD olny when CDWechseler is selected");
+    }
+}

src/test/java/device/cdPlayer/CDPlayerTest.java

@@ -428,5 +428,20 @@ class CDPlayerTest {
         );
     }
 
+    @ParameterizedTest
+    @MethodSource("changeToNextCDData")
+    void changeToNextCDTest(String testName,String cases, CDPlayer _cdPlayer,Exception exception) {
+            Exception newException = assertThrows(exception.getClass(), () -> _cdPlayer.changeToNextCD());
+            assertEquals(ChangeCDOnlyOnCDWechselerException.class, newException.getClass());
+    }
+    static Stream<Arguments> changeToNextCDData () {
+        CDPlayer cdPlayer1 = new CDPlayer();
+
+        return Stream.of(
+                Arguments.of("[changeToNextCD() by CDWechselerNotSelected ] => shouldThrowAnException", "Case1", cdPlayer1,new ChangeCDOnlyOnCDWechselerException())
+        );
+    }
+
+
 
     }