Testing CsCheck's coverage of constrained search spaces

CsCheckTesting.cs

// See https://aka.ms/new-console-template for more information
using CsCheck;


Console.WriteLine("Hello, World!");

TestIteratedDirectIntegerSpaceCoverage();

void TestEnumeratedSpaceCoverage()
{
    const int iterations = 1000;
    const int spaceCardinality = 16;

    int totalCoverageCount = 0;
    int coverageSum = 0;

    var pointGenerator = Gen.Select(
        Gen.Bool, Gen.Bool, Gen.Bool, Gen.Bool,
        (a, b, c, d) => new PointInSpace(a, b, c, d)
    );


    for (int i = 0; i < iterations; i++)
    {
        pointGenerator.Enumerable.SampleOne(pointEnumerable =>
        {
            var dis = pointEnumerable.Take(spaceCardinality).Distinct();
            var count = dis.Count();
            //Console.WriteLine(count);

            coverageSum += count;

            if (count == spaceCardinality)
                totalCoverageCount++;
        });
    }

    Console.WriteLine($"Covered the entire search space in ({totalCoverageCount}) {(decimal)totalCoverageCount / iterations:P2} of cases");
    Console.WriteLine($"Covered an average of {(decimal)coverageSum / (iterations * spaceCardinality):P2} cases");
}

void TestIteratedSpaceCoverage()
{
    const int iterations = 1000;
    const int spaceCardinality = 16;

    int totalCoverageCount = 0;
    int coverageSum = 0;

    var pointGenerator = Gen.Select(
        Gen.Bool, Gen.Bool, Gen.Bool, Gen.Bool,
        (a, b, c, d) => new PointInSpace(a, b, c, d)
    );


    for (int i = 0; i < iterations; i++)
    {
        var uniquePoints = new HashSet<PointInSpace>();

        pointGenerator.Sample(
            point =>{
                uniquePoints.Add(point);
            },
            iter: spaceCardinality,
            threads: 1
        );

        coverageSum += uniquePoints.Count;

        if (uniquePoints.Count == spaceCardinality)
            totalCoverageCount++;
    }

    Console.WriteLine($"Covered the entire search space in ({totalCoverageCount}) {(decimal)totalCoverageCount / iterations:P2} of cases");
    Console.WriteLine($"Covered an average of {(decimal)coverageSum / (iterations * spaceCardinality):P2} cases");
}

void TestIteratedIntegerSpaceCoverage()
{
    const int iterations = 10000000;
    const int spaceCardinality = 16;

    int totalCoverageCount = 0;
    int coverageSum = 0;

    var pointGenerator = Gen.Select(
        Gen.Int,
        i => new PointInSpace(
            (i & 1) == 0,
            (i & 2) == 0,
            (i & 4) == 0,
            (i & 8) == 0)
    );


    for (int i = 0; i < iterations; i++)
    {
        var uniquePoints = new HashSet<PointInSpace>();

        pointGenerator.Sample(
            point =>
            {
                uniquePoints.Add(point);
            },
            iter: spaceCardinality,
            threads: 1
        );

        coverageSum += uniquePoints.Count;

        if (uniquePoints.Count == spaceCardinality)
            totalCoverageCount++;
    }

    Console.WriteLine($"Covered the entire search space in ({totalCoverageCount}) {(decimal)totalCoverageCount / iterations:P8} of cases");
    Console.WriteLine($"Covered an average of {(decimal)coverageSum / (iterations * spaceCardinality):P8} cases");
}

void TestIteratedDirectIntegerSpaceCoverage()
{
    const int iterations = 10000000;
    const int spaceCardinality = 16;

    int totalCoverageCount = 0;
    int coverageSum = 0;

    var intGen = Gen.Int[0, spaceCardinality];


    for (int i = 0; i < iterations; i++)
    {
        var uniquePoints = new HashSet<int>();

        intGen.Sample(
            point => {
                uniquePoints.Add(point);
            },
            iter: spaceCardinality,
            threads: 1
        );

        coverageSum += uniquePoints.Count;

        if (uniquePoints.Count == spaceCardinality)
            totalCoverageCount++;
    }

    Console.WriteLine($"Covered the entire search space in ({totalCoverageCount}) {(decimal)totalCoverageCount / iterations:P8} of cases");
    Console.WriteLine($"Covered an average of {(decimal)coverageSum / (iterations * spaceCardinality):P8} cases");
}

public record PointInSpace(bool A, bool B, bool C, bool D);