Created Tests and then made FizzBuzz pass them

src/main/java/FizzBuzz.java

@@ -1,2 +1,9 @@
 public class FizzBuzz {
+    public static String FizzBuzz(int i){
+        if (i % 3 == 0 && i % 5 == 0) return "FizzBuzz";
+        else if(i % 3 == 0) return "Fizz";
+        else if (i % 5 == 0) return "Buzz";
+
+        else return String.valueOf(i);
+    }
 }

src/test/java/FizzBuzzTest.java

@@ -1,2 +1,41 @@
+import org.junit.*;
+
 public class FizzBuzzTest {
+    @Test
+    public void checkThreeTest(){
+        //Given
+        int input = 3;
+        String expected = "Fizz";
+        //When
+        String actual = FizzBuzz.FizzBuzz(input);
+        Assert.assertEquals(expected,actual);
+    }
+    @Test
+    public void checkFiveTest(){
+        //Given
+        int input = 5;
+        String expected = "Buzz";
+        //When
+        String actual = FizzBuzz.FizzBuzz(input);
+        Assert.assertEquals(expected,actual);
+    }
+    @Test
+    public void checkFifteenTest(){
+        //Given
+        int input = 15;
+        String expected = "FizzBuzz";
+        //When
+        String actual = FizzBuzz.FizzBuzz(input);
+        Assert.assertEquals(expected,actual);
+    }
+    @Test
+    public void checkElseTest(){
+        //Given
+        int input = 8;
+        String expected = "8";
+        //When
+        String actual = FizzBuzz.FizzBuzz(input);
+        Assert.assertEquals(expected,actual);
+    }
+
 }