lab move N --> x - 1

src/main/c/labyrinth.c

@@ -25,7 +25,7 @@ void turn_direction_right(Direction *direction){
 void lab_move(unsigned short *x, unsigned short *y, Direction direction){
 
     if (direction == N){
-        *x = 0;
+        *x = *x - 1;
         return;
     }
 

src/test/c/test_labyrinth.c

@@ -81,3 +81,20 @@ void test_lab_move_from_1_1_N_expected_0_1(void)
 	TEST_ASSERT_TRUE(x == x_expected && y == y_expected);
 }
 
+void test_lab_move_from_5_5_N_expected_4_5(void)
+{
+    /* arrange */
+	unsigned short x = 5;
+	unsigned short y = 5;
+    Direction direction = N;
+	
+	unsigned short x_expected = 4;
+	unsigned short y_expected = 5;
+
+    /* act */
+    lab_move(&x, &y, direction);
+
+    /* assert */
+	TEST_ASSERT_TRUE(x == x_expected && y == y_expected);
+}
+