first unit test creation

src/test/java/dotsandboxes/DotsAndBoxesGridTest.java

@@ -28,4 +28,38 @@ public class DotsAndBoxesGridTest {
     }
 
    // FIXME: You need to write tests for the two known bugs in the code.
+   @Test
+   public void boxCompleteDetectsCompletedBoxes() {
+     // code to test that boxComplete returns true for boxes that *are complete* goes here 
+       DotsAndBoxesGrid case1 = new DotsAndBoxesGrid(5, 5, 2);
+       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() {
+     // code to test that boxComplete returns false for boxes that *are not complete* goes here
+     DotsAndBoxesGrid case2 = new DotsAndBoxesGrid(5, 5, 2);
+       case2.drawHorizontal(0, 0, 0);
+       case2.drawVertical(0, 0, 1);
+       case2.drawHorizontal(0, 1, 0);
+       case2.drawVertical(0, 0, 1);
+       assertFalse(case2.boxComplete(0, 0));
+   }
+   @Test
+   public void drawMethodsDetectRedrawnLines() {
+     // code to test that drawHorizontal throws an exception if the line was already drawn goes here
+     // code to test that drawVertical throws an exception if the line was already drawn goes here
+     DotsAndBoxesGrid case3 = new DotsAndBoxesGrid(5, 5, 2);
+     case3.drawHorizontal(0, 0, 1);
+     case3.drawVertical(0, 0, 1);
+     assertAll(
+       ()->assertThrows(IllegalStateException.class, ()-> case3.drawHorizontal(0, 0, 1), "No horizonal line has been drawn"),
+       ()->assertThrows(IllegalStateException.class, ()-> case3.drawVertical(0, 0, 1), "No vertical line has been drawn")
+       );
+     
+     
+   }
 }