Added unit tests

src/test/java/dotsandboxes/DotsAndBoxesGridTest.java

@@ -27,5 +27,34 @@ public class DotsAndBoxesGridTest {
         assertTrue(true);
     }
 
-    // FIXME: You need to write tests for the two known bugs in the code.
+    @Test
+    public void boxCompleteDetectsCompletedBoxes() {
+        logger.info("Test to show that boxComplete returns true if all sides have been drawn");
+        DotsAndBoxesGrid case1 = new DotsAndBoxesGrid(4,4,1);
+        case1.drawHorizontal(0,0,0);
+        case1.drawVertical(0,0,1);
+        case1.drawHorizontal(0,1,0);
+        case1.drawVertical(1,0,1);
+        assertTrue(case1.boxComplete(0,0));
+    }
+
+    @Test
+    public void boxCompleteDetectsIncompleteBoxes() {
+        logger.info("Test to show that boxComplete returns false if not all sides have been drawn");
+        DotsAndBoxesGrid case1 = new DotsAndBoxesGrid(4,4,1);
+        case1.drawHorizontal(0,0,0);
+        case1.drawVertical(0,0,1);
+        case1.drawHorizontal(0,1,0);
+        assertFalse(case1.boxComplete(0,0));
+    }
+
+    @Test
+    public void drawMethodsDetectRedrawnLines() {
+        logger.info("Test to show that drawHorizontal throws an exception if the line was already drawn");
+        DotsAndBoxesGrid case1 = new DotsAndBoxesGrid(4,4,1);
+        case1.drawHorizontal(0,0,0);
+        assertThrows(IllegalStateException.class, () -> {
+            case1.drawHorizontal(0,0,0);
+        });
+    }
 }