Added unit testing

src/test/java/dotsandboxes/DotsAndBoxesGridTest.java

@@ -27,5 +27,36 @@ public class DotsAndBoxesGridTest {
         assertTrue(true);
     }
 
-    // FIXME: You need to write tests for the two known bugs in the code.
+    @Test
+    public void testBoxComplete() {
+        logger.info("Test to show that box complete runs correctly");
+        DotsAndBoxesGrid DaB = new DotsAndBoxesGrid(10, 10, 1);
+        Assertions.assertEquals(false, DaB.boxComplete(4, 3));
+    }
+
+    @Test
+    public void testdrawHorizontal() {
+        logger.info("Test to show horizontal lines can only be draw once in the same place");
+        DotsAndBoxesGrid DaB = new DotsAndBoxesGrid(10, 10, 1);
+        DaB.drawHorizontal(4, 2, 1);
+        Assertions.assertThrows(IllegalStateException.class, () -> {
+            DaB.drawHorizontal(4,2, 1);
+        }, "There is already a horizontal line here. ");
+
+    }
+
+    @Test
+    public void testdrawVertical() {
+        logger.info("Test to show vertical lines can only be draw once in the same place");
+        DotsAndBoxesGrid DaB = new DotsAndBoxesGrid(10, 10, 1);
+        DaB.drawVertical(4, 2, 1);
+        Assertions.assertThrows(IllegalStateException.class, () -> {
+            DaB.drawVertical(4,2, 1);
+        }, "There is already a vertical line here. ");
+    }
+
 }
+
+
+// FIXME: You need to write tests for the two known bugs in the code.
+