Added new unit tests to test the boxComplete method is working, and also that...

Added new unit tests to test the boxComplete method is working, and also that drawing the same line twice throws an exception

src/test/java/dotsandboxes/DotsAndBoxesGridTest.java

@@ -26,6 +26,49 @@ public class DotsAndBoxesGridTest {
         logger.info("Dummy test to show the test suite runs");
         assertTrue(true);
     }
-
+    
     // FIXME: You need to write tests for the two known bugs in the code.
+    @Test
+    public void testBoxCompleteWorking() {
+        logger.info("Test that box completion is true for a valid box coordinate");
+        
+        // First draw a valid box
+        DotsAndBoxesGrid dotsAndBoxesGrid = new DotsAndBoxesGrid(8, 8, 2);
+        dotsAndBoxesGrid.drawHorizontal(1, 1, 1);
+        dotsAndBoxesGrid.drawHorizontal(1, 2, 1);
+        dotsAndBoxesGrid.drawVertical(1, 1, 1);
+        dotsAndBoxesGrid.drawVertical(2, 1, 1);
+        // Assert our box is valid
+        boolean isBox = dotsAndBoxesGrid.boxComplete(1, 1);
+        assertTrue(isBox);
+
+        // Now we will test with an invalid box, which should fail
+        logger.info("Test that box completion is false for an invalid box coordinate");
+        
+        // First draw only a partial box
+        dotsAndBoxesGrid = new DotsAndBoxesGrid(8, 8, 2);
+        dotsAndBoxesGrid.drawHorizontal(1, 1, 1);
+        dotsAndBoxesGrid.drawHorizontal(1, 2, 1);
+        dotsAndBoxesGrid.drawVertical(1, 1, 1);
+        // Now assert an unfinished box isn't valid
+        isBox = dotsAndBoxesGrid.boxComplete(1, 1);
+        assertFalse(isBox);
+
+    }
+        
+    @Test
+    public void testDoubleDrawForbidden() {
+        logger.info("Test that drawing the same line twice is forbidden (horizontal)");
+        // Instantiate the grid and draw a horizontal line twice, assert an exception
+        DotsAndBoxesGrid dotsAndBoxesGrid = new DotsAndBoxesGrid(8, 8, 2);
+        dotsAndBoxesGrid.drawHorizontal(1, 1, 1);
+        assertThrows(Exception.class, () -> dotsAndBoxesGrid.drawHorizontal(1, 1, 1));
+
+        logger.info("Test that drawing the same line twice is forbidden (vertical)");
+        // Instantiate the grid and draw a vertical line twice, assert an exception
+        DotsAndBoxesGrid dotsAndBoxesGrid2 = new DotsAndBoxesGrid(8, 8, 2);
+        dotsAndBoxesGrid2.drawVertical(1, 1, 1);
+        assertThrows(Exception.class, () -> dotsAndBoxesGrid2.drawVertical(1, 1, 1));
+    }
+    
 }