using System;
using System.Collections.Generic;
using System.Linq;
using System.Utility;
using NUnit.Framework;

namespace Chernobyl
{
    [TestFixture, Description("Tests for LazyExt type")]
    public class LazyTests
    {
        [Test]
        public void SwitchCreatesOnlyWhenNeeded()
        {
            var lazy = new Lazy<IEnumerable<int>>(() => Enumerable.Range(1, 3));
            var enumerable = lazy.Switch();

            lazy.IsValueCreated.IsFalse(nameof(lazy.IsValueCreated));
            var count = enumerable.Count();
            lazy.IsValueCreated.IsTrue(nameof(lazy.IsValueCreated));
        }
    }
}