BordComputerTest.changeDeviceTest forth case

src/test/java/BordComputerTest.java

@@ -94,6 +94,8 @@ class BordComputerTest {
             assertThat(currentDevice).describedAs(testName).isNotEqualTo(prvDevice);
         }else if (caseNr == 3) {
             assertThat(inputBC.changeDevice()).describedAs(testName).isNotNull();
+        }else if (caseNr == 4) {
+            assertThat(inputBC.changeDevice()).describedAs(testName).isNotNull();
         }
     }
 
@@ -120,12 +122,20 @@ class BordComputerTest {
         bc2.setDevices();
         m =bc2.changeDevice();
 
+        //forth case
+        BordComputer bc3 = new BordComputer();
+        bc3.readConfig();
+        bc3.setDevices();
+        m =bc3.changeDevice();
+        m =bc3.changeDevice(); //CDPlayer
+
 
 
         return Stream.of(
                 Arguments.of("The order of the installedDevices should be changed ", bc,currentDevices,null,"",1),
                 Arguments.of("The active Device should be changed ", bc1,null,prvDevice,"",2),
-                Arguments.of("The new Device returns a String ", bc2,null,prvDevice,bc2.activeDevice.toString(),3)
+                Arguments.of("The new Device returns a String ", bc2,null,prvDevice,bc2.activeDevice.toString(),3),
+                Arguments.of("The new Device returns a String ", bc3,null,prvDevice,null,4)
         );
     }
 }