Method chooseItem of CDPlayer tested on validInput->shouldReturnMsgWithinTheItemNr.

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

@@ -96,7 +96,7 @@ public class CDPlayer implements Device {
             throw new ItemNumberNotFoundException();
         }
 
-        return null;
+        return loadedCD.getPlayList()[itemNr];
     }
 
     @Override

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

@@ -329,7 +329,7 @@ class CDPlayerTest {
 
     @ParameterizedTest
     @MethodSource("chooseItemTestData")
-    void chooseItemTest(String testName,String cases, CDPlayer _cdPlayer,Exception exception , String expectedResult) {
+    void chooseItemTest(String testName,String cases, CDPlayer _cdPlayer,Exception exception ) {
         if(cases.equals("Case1")) {
             Exception newException = assertThrows(exception.getClass(), () -> _cdPlayer.chooseItem(1));
             assertEquals(ReturnValueNullException.class, newException.getClass());
@@ -342,6 +342,9 @@ class CDPlayerTest {
             Exception newException = assertThrows(exception.getClass(), () -> _cdPlayer.chooseItem(-1));
             assertEquals(NegativeInputException.class, newException.getClass());
         }
+        if(cases.equals("Case4")) {
+            assertThat(_cdPlayer.chooseItem(1).contains("2")).describedAs(testName).isEqualTo(true);
+        }
     }
     static Stream<Arguments> chooseItemTestData () {
         CDPlayer cdPlayer1 = new CDPlayer();
@@ -354,9 +357,10 @@ class CDPlayerTest {
         cdPlayer2.tapOnCdFlap();
 
         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:negativeNumber] => shouldThrowItemNumberNotFoundException","Case3", cdPlayer2,new NegativeInputException(),"")
+                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:negativeNumber] => shouldThrowItemNumberNotFoundException","Case3", cdPlayer2,new NegativeInputException()),
+                Arguments.of("[chooseItem() by validInput] => shouldReturnMsgWithinTheItemNr","Case4", cdPlayer2,null)
         );
     }