public void FloorPlan_detects_adjacent_tiles()
{
FloorPlan plan = NSubstitute.Substitute.For <FloorPlan>();
plan.FloorTiles.AddRange(_FillArea(5, 5));
var center = plan.GetFloorTile(2, 2);
plan.GetNorth(center).Should().BeSameAs(plan.GetFloorTile(2, 1));
plan.GetSouth(center).Should().BeSameAs(plan.GetFloorTile(2, 3));
plan.GetWest(center).Should().BeSameAs(plan.GetFloorTile(1, 2));
plan.GetEast(center).Should().BeSameAs(plan.GetFloorTile(3, 2));
plan.GetNorth(center).Should().NotBeSameAs(plan.GetFloorTile(2, 3));
var corner = plan.GetFloorTile(0, 0);
plan.GetNorth(corner).Should().BeNull();
plan.GetSouth(corner).Should().BeSameAs(plan.GetFloorTile(0, 1));
plan.GetWest(corner).Should().BeNull();
plan.GetEast(corner).Should().BeSameAs(plan.GetFloorTile(1, 0));
corner = plan.GetFloorTile(4, 4);
plan.GetNorth(corner).Should().BeSameAs(plan.GetFloorTile(4, 3));
plan.GetSouth(corner).Should().BeNull();
plan.GetWest(corner).Should().BeSameAs(plan.GetFloorTile(3, 4));
plan.GetEast(corner).Should().BeNull();
}