public void Bishop_given_valid_coordinates_should_move_to_valid_co_ordinates(string initialCellPosition, int expectedOutcomesCount, string expectedOutcomesStr)
{
var initialPosition = new Position(initialCellPosition);
var bishop = new Bishop(initialPosition, PieceColours.White);
var possibleOutcomes = bishop.GetPossiblePositions(_direction);
possibleOutcomes.Count.Should().Be(expectedOutcomesCount);
var positions = possibleOutcomes.Select(x => x.CellPosition).ToList();
var expectedPossibleOutcomes = expectedOutcomesStr.Split(",", StringSplitOptions.RemoveEmptyEntries);
positions.Should().Contain(expectedPossibleOutcomes);
}