using Developpez.Dotnet.ComponentModel;
using NUnit.Framework;

namespace Developpez.Dotnet.Tests.ComponentModel
{
    [TestFixture(Description="Tests de la classe Singleton<T>")]
    public class SingletonTests
    {
        private class Foo
        {
            public static int InstanceCount { get; private set; }

            protected Foo()
            {
                InstanceCount++;
            }
        }

        private class Bar
        {
            public static int InstanceCount { get; private set; }

            protected Bar()
            {
                InstanceCount++;
            }
        }

        [Test(Description = "Vérifie qu'une instance unique existe pour un type donné")]
        public void Check_SingletonUniqueInstance()
        {
            Assert.AreEqual(Foo.InstanceCount, 0);
            Assert.AreEqual(Bar.InstanceCount, 0);
            
            Foo foo1 = Singleton<Foo>.Instance;
            Foo foo2 = Singleton<Foo>.Instance;
            
            Assert.AreSame(foo1, foo2);
            Assert.AreEqual(Foo.InstanceCount, 1);
            Assert.AreEqual(Bar.InstanceCount, 0);

            Bar bar1 = Singleton<Bar>.Instance;
            Bar bar2 = Singleton<Bar>.Instance;

            Assert.AreSame(bar1, bar2);
            Assert.AreEqual(Foo.InstanceCount, 1);
            Assert.AreEqual(Bar.InstanceCount, 1);
        }
    }
}