SelectionSamplingTests.cs

using AlgorithmsAndDataStructures.Algorithms.Sampling;
using System;
using System.Linq;
using Xunit;

namespace AlgorithmsAndDataStructures.Tests.Algorithm.Sampling
{
    public class SelectionSamplingTests
    {
        [Fact]
        public void CanSelectSample()
        {
            var sut = new SelectionSampling();
            var population = new[] { 1, 2 };
            const int sampleSize = 1;
            var sample = sut.GetRandomSample(population, sampleSize);

            Assert.True(sample[0] != 0);
        }

        [Fact]
        public void ThrowsOnIncorrectParams()
        {
            var sut = new SelectionSampling();
            var population = new[] { 1, 2 };
            const int sampleSize = 3;
            Assert.Throws<ArgumentException>(() => sut.GetRandomSample(population, sampleSize));
        }

        [Fact]
        public void Fuzzy()
        {
            var sut = new SelectionSampling();
            var random = new Random();
            var population = new int[100];

            for (var i = 0; i < population.Length; i++)
            {
                population[i] = random.Next(1, 10000);
            }
            var sampleSize = random.Next(1,100);

            var sample = sut.GetRandomSample(population, sampleSize);

            Assert.True(sample.All(arg => arg != 0));
        }
    }
}