RandomExtensions Class

public static class RandomExtensions

using System;
using System.Collections;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Reflection;
using KGySoft.CoreLibraries;

public static class Example
{
    public static void Main()
    {
        // Or FastRandom for the fastest results, or SecureRandom for cryptographically safe results.
        var rnd = new Random();

        // Next... for all simple types:
        Console.WriteLine(rnd.NextBoolean());
        Console.WriteLine(rnd.NextDouble(Double.PositiveInfinity)); // see also the overloads
        Console.WriteLine(rnd.NextString()); // see also the overloads
        Console.WriteLine(rnd.NextDateTime()); // also NextDate, NextDateTimeOffset, NextTimeSpan
        Console.WriteLine(rnd.NextEnum<ConsoleColor>());
        // and NextByte, NextSByte, NextInt16, NextDecimal, etc.

        // NextObject: for practically anything. See also GenerateObjectSettings.
        Console.WriteLine(rnd.NextObject<Person>().Dump()); // custom type
        Console.WriteLine(rnd.NextObject<(int, string)>()); // tuple
        Console.WriteLine(rnd.NextObject<IConvertible>()); // interface implementation
        Console.WriteLine(rnd.NextObject<MarshalByRefObject>()); // abstract type implementation
        Console.WriteLine(rnd.NextObject<int[]>().Dump()); // array
        Console.WriteLine(rnd.NextObject<IList<IConvertible>>().Dump()); // some collection of an interface
        Console.WriteLine(rnd.NextObject<Func<DateTime>>().Invoke()); // delegate with random result

        // specific type for object (useful for non-generic collections)
        Console.WriteLine(rnd.NextObject<ArrayList>(new GenerateObjectSettings
        {
            SubstitutionForObjectType = typeof(ConsoleColor)
        }).Dump());

        // literally any random object
        Console.WriteLine(rnd.NextObject<object>(new GenerateObjectSettings
        {
            AllowDerivedTypesForNonSealedClasses = true
        })/*.Dump()*/); // dump may end up in an exception for property getters or even in an endless recursion
    }

    private static string Dump(this object o)
    {
        if (o == null)
            return "<null>";

        if (o is IConvertible convertible)
            return convertible.ToString(CultureInfo.InvariantCulture);

        if (o is IEnumerable enumerable)
            return $"[{String.Join(", ", enumerable.Cast<object>().Select(Dump))}]";

        return $"{{{String.Join("; ", o.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance).Select(p => $"{p.Name} = {Dump(p.GetValue(o))}"))}}}";
    }
}

public class Person
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public DateTime BirthDate { get; set; }
    public List<string> PhoneNumbers { get; set; }
}

// A possible output of the code above can be the following:
// False
// 1,65543763243888E+266
// }\&qc54# d
// 8806. 02. 18. 6:25:21
// White
// {FirstName = Jemp; LastName = Aeltep; BirthDate = 07/04/2003 00:00:00; PhoneNumbers = [17251827, 7099649772]}
// (1168349297, oufos)
// Renegotiated
// System.Net.Sockets.NetworkStream
// [336221768]
// [Off, Invalid]
// 1956. 08. 24. 4:28:57
// [Yellow, Gray]
// System.Xml.XmlCharCheckingReader+<ReadElementContentAsBinHexAsync>d__40 *