src/main/java/dotsandboxes/DotsAndBoxesGrid.java

@@ -112,7 +112,9 @@ public class DotsAndBoxesGrid {
 
         // A box is complete if the north and south horizontals and the east and west verticals have all been drawn.
         // FIXME: You'll need to fix this code (after writing a test first).
-        return true;
+        return (getHorizontal(x, y) && getHorizontal(x, y + 1) && getVertical(x, y) && getVertical(x + 1, y));
+
+        //return true;
     }
 
     /** Tries to claim a box for a player. If the box is complete, sets the ownership and returns true. */
@@ -139,9 +141,12 @@ public class DotsAndBoxesGrid {
             throw new IndexOutOfBoundsException(String.format("y was %d, which is out of range. Range is 0 to %d", y, height));
         }
 
-        // FIXME: You need to throw an exception if the line was already drawn.
-
+        if (getHorizontal(x, y)) {
+            throw new RuntimeException("Horizontal was already drawn");
+        } else {
             this.horizontals[x][y] = true;
+        }
+        
 
         // Try to claim the north or south boxes
         boolean claimN = claimBox(x, y-1, player);
@@ -171,8 +176,12 @@ public class DotsAndBoxesGrid {
         }
 
         // You need to throw an exception if the line was already drawn.
-
+        if (getVertical(x, y)) {
+            throw new RuntimeException("Vertical was already drawn");
+        } else {
             this.verticals[x][y] = true;
+        }
+        
         // Try to claim the north or south boxes
         boolean claimE = claimBox(x, y, player);
         boolean claimW = claimBox(x-1, y, player);