public static Coordinate Move(this Coordinate coordinates, Compass4Points direction, int steps = 1)
{
steps.ThrowIfBelow(1, nameof(steps));
switch (direction)
{
case Compass4Points.North:
coordinates = coordinates.Up(steps);
break;
case Compass4Points.South:
coordinates = coordinates.Down(steps);
break;
case Compass4Points.East:
coordinates = coordinates.Right(steps);
break;
case Compass4Points.West:
coordinates = coordinates.Left(steps);
break;
default:
var message = $"Unrecognised direction [{direction}]";
throw new ArgumentException(message);
}
return(coordinates);
}
public void ARandomEnum_ShouldHaveAGoodDistribution()
{
var enumItems = EnumHelpers.Values <Compass4Points>().ToList();
var enumCount = enumItems.Count;
int numRolls = enumCount * 1000;
var rolls = new Compass4Points[numRolls];
var generator = new RandomNumberGenerator();
for (int i = 1; i < numRolls; i++)
{
rolls[i] = generator.Enum <Compass4Points>();
}
var samples = enumItems.Select(enumItem =>
{
var count = rolls.Count(roll => enumItem == roll);
return(enumItem: enumItem, count: count);
}).ToList();
var midpoint = 1000;
var percent = 10.0 / 100;
var min = midpoint - (midpoint * percent);
var max = midpoint + (midpoint * percent);
var errorMessage = new StringBuilder();
foreach (var sample in samples)
{
errorMessage.AppendLine($"Expected [{sample.enumItem}] to be in the range [{min},{max}] and it was [{sample.count}]");
}
foreach (var sample in samples)
{
Assert.True(sample.count >= min && sample.count <= max, errorMessage.ToString());
}
}