public void GetRelativeDirectionShould_CalculatesRelativeMoveDirectionCorrectly(int firstX, int firstY, int secondX, int secondY, MoveDirection expectedDirection)
{
var currentBit = new SnakeBit {
X = firstX, Y = firstY
};
var nextBit = new SnakeBit {
X = secondX, Y = secondY
};
var direction = currentBit.GetRelativeDirection(nextBit);
direction.Should().Be(expectedDirection);
}
public void GetRelativeDirectionShould_Throw_ArgumentException_When_NextPositionIsSameAsCurrent()
{
Action action = () =>
{
var current = new SnakeBit {
X = 7, Y = 10
};
var next = new SnakeBit {
X = 7, Y = 10
};
current.GetRelativeDirection(next);
};
action.Should().Throw <ArgumentException>();
}
public void GetRelativeDirectionShould_Throw_NotSupportedException_When_NextIsDiagonallyPositioned()
{
Action action = () =>
{
var current = new SnakeBit {
X = 7, Y = 10
};
var next = new SnakeBit {
X = 8, Y = 11
};
current.GetRelativeDirection(next);
};
action.Should().Throw <NotSupportedException>();
}
public static MoveDirection GetRelativeDirection(this SnakeBit current, SnakeBit next)
{
if (current.X == next.X && current.Y == next.Y)
{
throw new ArgumentException("Current and next cannot be in the same position");
}
if (current.X == next.X)
{
// Moving vertically
return(current.Y < next.Y ? MoveDirection.Up : MoveDirection.Down);
}
else if (current.Y == next.Y)
{
// Moving horizontally
return(current.X < next.X ? MoveDirection.Left : MoveDirection.Right);
}
else
{
throw new NotSupportedException("Cannot move diagonally");
}
}
