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

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

@@ -158,16 +158,20 @@ public class RadioPlayer implements Device {
 
     @Override
     public String chooseItem(int itemNr) {
-        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");
+        if (regionPlaylist.contains(playedStation)) {
+            playedStation = regionPlaylist.get(itemNr - 1);
+            return ("Radio is playing station: 0" + (regionPlaylist.indexOf(playedStation) + 1) + " " + this.playedStation + " from regional playlist");
         } else {
-            playedStation = savedPlaylist.get(itemNr - 1);
-            return ("Radio is playing station: 0" + (savedPlaylist.indexOf(playedStation) + 1) + " " + this.playedStation + " from saved playlist");
-
+            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");
+            }
         }
     }
 

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

@@ -187,11 +187,15 @@ class RadioPlayerTest {
         rp1.chooseItem(5);
         RadioPlayer rp2 = new RadioPlayer();
         rp2.chooseItem(-1);
+        RadioPlayer rp3 = new RadioPlayer();
+        rp3.changeRegion("BY");
+        rp3.chooseItem(2);
 
         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 lower than 0. First station in playlist gets played", rp2, "YouFM")
+                Arguments.of("Test select station in saved playlist to play with nr is lower than 0. First station in playlist gets played", rp2, "YouFM"),
+                Arguments.of("Test select station in regional playlist to play with nr isn`t bigger than playlist size", rp3, "Bayern 1")
         );
     }