Added unit tests to test for the two known bug issues

src/test/java/dotsandboxes/DotsAndBoxesGridTest.java

@@ -28,4 +28,58 @@ public class DotsAndBoxesGridTest {
     }
 
     // FIXME: You need to write tests for the two known bugs in the code.
+
+    // Test to check for box completion , if it has 4 lines drawn then it is complete, else it is incomplete.
+    @Test
+    public void testForBoxCompletion(){
+        logger.info("Testing to check that a box is fully drawn, only when it is complete");
+
+        // Create new grid
+        DotsAndBoxesGrid grid = new DotsAndBoxesGrid(2,2,1);
+
+        // Check for empty box
+        assertFalse(grid.boxComplete(0,0), "Empty box is incomplete and should not be claimable");
+
+        // Draw vertical line
+        grid.drawVertical(0,0,1);
+        // Box is incomplete
+        assertFalse(grid.boxComplete(0,0),"Box is incomplete and should not be claimable");
+
+        // Draw a horizontal line
+        grid.drawHorizontal(0,0,1);
+        // Box is incomplete
+        assertFalse(grid.boxComplete(0,0),"Box is incomplete and should not be claimable");
+
+        // Draw another vertical line and another horizontal line to complete the box
+        grid.drawVertical(1,0,1);
+        grid.drawHorizontal(0,1,1);
+
+        // Check for complete box
+        assertTrue(grid.boxComplete(0,0), "Box is complete and should be fully drawn and claimable");
+    }
+        // Test to check if a line can be drawn, and to throw an illegalStateException if the line has already been
+        // drawn at the same coordinates (duplicate).
+        @Test
+        public void TestForDuplicateLinesDrawn(){
+            logger.info("Testing to check that it is disallowed to draw over a line that has already been drawn");
+            // Create new grid
+            DotsAndBoxesGrid grid = new DotsAndBoxesGrid(2,2,1);
+
+            // Test to check if a vertical and horizontal line can be drawn to the grid
+            assertFalse(grid.drawVertical(0,0,1));
+            assertFalse(grid.drawHorizontal(0,0,1));
+
+            // Test to catch IllegalStateException, when a duplicate vertical line draw attempt is made
+            // at the same coordinates.
+            assertThrows(
+                    IllegalStateException.class,()-> grid.drawVertical(0,0,1)
+                    ,"This line has already been drawn");
+
+            // Test to catch IllegalStateException, when a duplicate horizontal line draw attempt is made
+            // at the same coordinates.
+            assertThrows(
+                    IllegalStateException.class, () -> grid.drawHorizontal(0,0,1),
+                    "This line has already been drawn");
+        }
+
 }