Method chooseItem of CDPlayer tested on invalidInput->negativeNumber.

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

@@ -89,9 +89,13 @@ public class CDPlayer implements Device {
         if(this.loadedCD==null){
             throw new ReturnValueNullException();
         }
+        if(itemNr<0){
+            throw new NegativeInputException();
+        }
         if(!(itemNr>=0  && itemNr<loadedCD.getPlayList().length)){
             throw new ItemNumberNotFoundException();
         }
+
         return null;
     }
 

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

@@ -0,0 +1,7 @@
+package device.cdPlayer.exceptions;
+
+public class NegativeInputException extends RuntimeException{
+    public NegativeInputException() {
+        super("InputNumber must be positive.");
+    }
+}

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

@@ -338,6 +338,10 @@ class CDPlayerTest {
             Exception newException = assertThrows(exception.getClass(), () -> _cdPlayer.chooseItem(200));
             assertEquals(ItemNumberNotFoundException.class, newException.getClass());
         }
+        if(cases.equals("Case3")) {
+            Exception newException = assertThrows(exception.getClass(), () -> _cdPlayer.chooseItem(-1));
+            assertEquals(NegativeInputException.class, newException.getClass());
+        }
     }
     static Stream<Arguments> chooseItemTestData () {
         CDPlayer cdPlayer1 = new CDPlayer();
@@ -351,7 +355,8 @@ class CDPlayerTest {
 
         return Stream.of(
                 Arguments.of("[chooseItem() by notSetCD ] => shouldThrowReturnValueNullException","Case1", cdPlayer1,new ReturnValueNullException(),""),
-                Arguments.of("[chooseItem() by invalidInput ] => shouldThrowItemNumberNotFoundException","Case2", cdPlayer2,new ItemNumberNotFoundException(),"")
+                Arguments.of("[chooseItem() by invalidInput ] => shouldThrowItemNumberNotFoundException","Case2", cdPlayer2,new ItemNumberNotFoundException(),""),
+                Arguments.of("[chooseItem() by invalidInput:negativeNumber] => shouldThrowItemNumberNotFoundException","Case3", cdPlayer2,new NegativeInputException(),"")
         );
     }