using System;
using System.Text;
using System.Diagnostics;
using NUnit.Framework;

namespace StructBenchmarking
{
    public class Benchmark : IBenchmark
    {
        public double MeasureDurationInMs(ITask task, int repetitionCount)
        {
            GC.Collect();
            GC.WaitForPendingFinalizers();
            task.Run();
            var result = 0.0;
            for (var i = 0; i < repetitionCount; i++)
            {
                Stopwatch stopWatch = new Stopwatch();
                stopWatch.Start();
                task.Run();
                stopWatch.Stop();
                result += stopWatch.Elapsed.TotalMilliseconds;
            }
            return result / repetitionCount;
        }
    }
    public class StringBuilderMaker : ITask
    {
        public void Run()
        {
            var str = new StringBuilder();
            for (var i = 0; i < 10000; i++)
                str.Append("a");
        }
    }
    public class StringMaker : ITask
    {
        public void Run()
        {
            var str = new string('a', 10000);
        }
    }

    [TestFixture]
    public class RealBenchmarkUsageSample
    {
        [Test]
        public void StringConstructorFasterThanStringBuilder()
        {
            var benchmark = new Benchmark();
            var stringMaker = new StringMaker();
            var stringBuilderMaker = new StringBuilderMaker();
            stringMaker.Run();
            stringBuilderMaker.Run();
            var testCount = 100;
            var stringResult = benchmark.MeasureDurationInMs(stringMaker, testCount);
            var stringBuilderResult = benchmark.MeasureDurationInMs(stringBuilderMaker, testCount);
            Assert.Less(stringBuilderResult, stringResult);
        }
    }
}