As I have understood this class, its purpose is to move a snake in a world where it is alone. Before moving the head it checks for collisions with Obstacle, Food and itself. However, the check does not consider that the tail will also move when forceGrowth is false and will incorrectly throw a SnakeCollision when a snake moves to its tail's previous location. An exception is when the snake is 2 parts long, because that would mean that the snake is moving backwards.
As I have understood this class, its purpose is to move a snake in a world where it is alone. Before moving the head it checks for collisions with Obstacle, Food and itself. However, the check does not consider that the tail will also move when
forceGrowthisfalseand will incorrectly throw aSnakeCollisionwhen a snake moves to its tail's previous location. An exception is when the snake is 2 parts long, because that would mean that the snake is moving backwards.