added third test case for chooseItem() & and added productive code for RadioPlayer

src/main/java/device/radioPlayer/RadioPlayer.java

@@ -161,9 +161,13 @@ public class RadioPlayer implements Device {
         if (itemNr > savedPlaylist.size()) {
             playedStation = savedPlaylist.get(savedPlaylist.size() - 1);
             return ("Radio is playing station: 0" + savedPlaylist.size() + " " + this.playedStation + " from saved playlist");
+        } else if (itemNr < 1) {
+            playedStation = savedPlaylist.get(0);
+            return ("Radio is playing station: 01 " + this.playedStation + " from saved playlist");
         } else {
             playedStation = savedPlaylist.get(itemNr - 1);
             return ("Radio is playing station: 0" + (savedPlaylist.indexOf(playedStation) + 1) + " " + this.playedStation + " from saved playlist");
+
         }
     }
 
@@ -232,8 +236,7 @@ public class RadioPlayer implements Device {
             savedPlaylist.remove(playedStation);
             savedPlaylist.add(0, station);
             return "Station " + playedStation + " is now on place 01 in saved playlist";
-        }
-        else {
+        } else {
             savedPlaylist.remove(playedStation);
             savedPlaylist.add(nr - 1, station);
             return "Station " + playedStation + " is now on place 0" + nr + "in saved playlist";

src/test/java/device/radioPlayer/RadioPlayerTest.java

@@ -185,10 +185,13 @@ class RadioPlayerTest {
         rp.chooseItem(2);
         RadioPlayer rp1 = new RadioPlayer();
         rp1.chooseItem(5);
+        RadioPlayer rp2 = new RadioPlayer();
+        rp2.chooseItem(-1);
 
         return Stream.of(
                 Arguments.of("Test select station in saved playlist to play with nr isn`t bigger than playlist size", rp, "Teddy"),
-                Arguments.of("Test select station in saved playlist to play with nr is bigger than playlist size. Last station in playlist gets played", rp1, "MegaHits")
+                Arguments.of("Test select station in saved playlist to play with nr is bigger than playlist size. Last station in playlist gets played", rp1, "MegaHits"),
+                Arguments.of("Test select station in saved playlist to play with nr is lower than 0. First station in playlist gets played", rp2, "YouFM")
         );
     }