all tests passing, add some tests

src/main/java/io/zipcoder/Music.java

@@ -8,7 +8,24 @@ public Music(String[] playList){
         this.playList = playList;
     }
 
-    public Integer selection(Integer startIndex, String selection){
-        return null;
+    public Integer selection(Integer startIndex, String selection) {
+        int distance = 0;
+        int selectionIndex = 0;
+
+        for (int i = startIndex; i < playList.length+1; i++) {
+            distance++;
+            if (i >= playList.length) {
+                i = 0;
+            }
+            if (playList[i].equals(selection)) {
+                selectionIndex = i;
+            }
+            if (distance >= playList.length) break;
+        }
+
+        int dist1 = Math.abs(selectionIndex - startIndex);
+        int dist2 = startIndex + playList.length - selectionIndex;
+        distance = Math.min(dist1, dist2);
+        return distance;
     }
 }

src/test/java/io/zipcoder/MusicTest.java

@@ -28,4 +28,28 @@ public void selectionTest2(){
         Integer actual = music.selection(startingIndex, selection);
         Assert.assertEquals(expected, actual);
     }
+
+    @Test
+    public void selectionTest3(){
+
+        String[] playlist = {"dancinginthedark","rio","liveoak","liveoak"};
+        Music music = new Music(playlist);
+        Integer startingIndex = 0;
+        String selection = "rio";
+        Integer expected = 1;
+        Integer actual = music.selection(startingIndex, selection);
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void selectionTest4(){
+
+        String[] playlist = {"wheniseeyouagain","borntorun","nothingelsematters","cecelia"};
+        Music music = new Music(playlist);
+        Integer startingIndex = 1;
+        String selection = "nothingelsematters";
+        Integer expected = 1;
+        Integer actual = music.selection(startingIndex, selection);
+        Assert.assertEquals(expected, actual);
+    }
 }