add a few files

src/main/java/edu/bristol/IMDBRating.java

@@ -1,16 +1,35 @@
+
 package edu.bristol;
 
+import java.text.DecimalFormat;
+
 public class IMDBRating
 {
     private float currentAverage = 0;
     private int ratingCount = 0;
 
     public float addNewRating(int newRating)
     {
-        int previousTotal = (int) (currentAverage * ratingCount);
-        int newTotal = previousTotal + newRating;
-        ratingCount++;
-        currentAverage = newTotal / ratingCount;
-        return currentAverage;
+        if (isValidRating(newRating)) {
+            int previousTotal = (int)(currentAverage * ratingCount);
+            float newTotal = previousTotal + newRating;
+            ratingCount++;
+            currentAverage = toTwoDecimal(newTotal / ratingCount);
+            System.out.println("current average is " + currentAverage);
+            return currentAverage;
+        }
+        else
+            return Float.NaN;
+    }
+    public boolean isValidRating(int rateNumber)
+    {
+        if (rateNumber < 0 || rateNumber > 10) return false;
+        else return true;
+    }
+    public float toTwoDecimal(float originalNumber)
+    {
+        DecimalFormat df = new DecimalFormat("0.00");
+        float newNumber = Float.parseFloat(df.format(originalNumber));
+        return newNumber;
     }
 }

src/test/java/edu/bristol/IMDBRatingTest.java

@@ -16,5 +16,20 @@ public void testAverageRating()
 
         averageRating = rater.addNewRating(4);
         assertTrue(averageRating == 3.0, "Adding 2nd rating: average should be 3.0");
+
+        averageRating = rater.addNewRating(6);
+        assertTrue(averageRating == 4.0, "Adding 3rd rating: average should be 4.0");
+
+        averageRating = rater.addNewRating(9);
+        assertTrue(averageRating == 5.25, "Adding 4th rating: average should be 5.25");
+
+        averageRating = rater.addNewRating(4);
+        assertTrue(averageRating == 5, "Adding 5th rating: average should be 5");
+
+        averageRating = rater.addNewRating(8);
+        assertTrue(averageRating == 5.5, "Adding 6th rating: average should be 5.5");
+
+        averageRating = rater.addNewRating(10);
+        assertTrue(averageRating == 6.14, "Adding 7th rating: average should be 6.14 ");
     }
 }