Method mute of CDPlayer tested after 5x louder() by checkingTheSavedOldVolume -> getOldVolumeShouldReturns_5.

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

@@ -26,6 +26,7 @@ public class CDPlayer implements Device {
     private List<String>favoriteSongs=new ArrayList<>();
 
     private boolean muted=false;
+    private int oldVolume=0;
 
     @Override
     public void louder() {
@@ -112,6 +113,7 @@ public class CDPlayer implements Device {
     @Override
     public String mute() {
         muted=true;
+        oldVolume=volume;
         volume=0;
         return ("Volume muted.");
     }
@@ -237,4 +239,9 @@ public class CDPlayer implements Device {
     public boolean isMuted() {
         return muted;
     }
+
+    public int getOldVolume() {
+        return oldVolume;
+    }
+
 }

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

@@ -547,13 +547,21 @@ class CDPlayerTest {
             _cdPlayer.mute();
             assertThat(_cdPlayer.getVolume()).describedAs(testName).isEqualTo(0);
         }
+        if(cases.equals("Case4")) {
+            for (int i = 0; i < 5; i++) {
+                _cdPlayer.louder();
+            }
+            _cdPlayer.mute();
+            assertThat(_cdPlayer.getOldVolume()).describedAs(testName).isEqualTo(5);
+        }
     }
     static Stream<Arguments> muteTestData () {
         CDPlayer cdPlayer1 = new CDPlayer();
         return Stream.of(
                 Arguments.of("[mute() by checkingTheReturnValue ] => ShouldReturnAString", "Case1", cdPlayer1, "Volume muted."),
                 Arguments.of("[mute() by checkingTheEffectAfterRun ] => VariableMutedShouldBeTrue", "Case2", cdPlayer1, "Volume muted."),
-                Arguments.of("[mute() after 2x louder() by checkingTheVolume] => VolumeShouldBeSetTo0", "Case3", cdPlayer1, "Volume muted.")
+                Arguments.of("[mute() after 2x louder() by checkingTheVolume] => VolumeShouldBeSetTo0", "Case3", cdPlayer1, "Volume muted."),
+                Arguments.of("[mute() after 5x louder() by checkingTheSavedOldVolume] => getOldVolumeShouldReturns_5", "Case4", cdPlayer1, "Volume muted.")
         );
     }