GameObjectContext pool memory leak fix. Todo: cover by test

UnityProject/Assets/Plugins/Zenject/OptionalExtras/IntegrationTests/Tests/Factories/TestMemoryPools/TestMemoryPoolLeaks.cs

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+using System;
+using System.Collections;
+using System.Collections.Generic;
+using ModestTree;
+using UnityEngine;
+using UnityEngine.TestTools;
+using Object = UnityEngine.Object;
+
+#pragma warning disable 219
+
+namespace Zenject.Tests.Bindings
+{
+	public class TestMemoryPoolLeaks : ZenjectIntegrationTestFixture
+	{
+		[UnityTest]
+		public IEnumerator TestFactoryProperties()
+		{
+			// making GameObjectContext prefab with pool
+			var prefab = new GameObject().AddComponent<GameObjectContext>();
+			prefab.Installers = new List<MonoInstaller> {
+				prefab.gameObject.AddComponent<FooInstallerScript>()
+			};
+
+			// install the prefab
+			PreInstall();
+			Container.Bind<GameObjectContext>().FromComponentInNewPrefab(prefab).AsTransient();
+			PostInstall();
+
+			yield return new WaitForEndOfFrame();
+
+			// spawn GameObjectContext
+			var context1 = Container.Resolve<GameObjectContext>();
+			// get pool
+			var pool1 = context1.Container.Resolve<Foo.Pool>();
+			// get pools count
+			var memoryPoolsCount1 = new List<WeakReference<IMemoryPool>>(StaticMemoryPoolRegistry.Pools).Count;
+
+			// destroy GameObjectContext
+			Object.DestroyImmediate(context1);
+
+			// make garbage collection // todo: ensure, that GameObjectContext completely destroyed and Pool.Dispose() has been invoked
+			prefab = null;
+			context1 = null;
+			pool1 = null;
+			yield return DestroyEverything();
+			yield return new WaitForEndOfFrame();
+			yield return new WaitForEndOfFrame();
+			GC.Collect(2);
+			GC.WaitForPendingFinalizers();
+
+			// waiting
+			yield return new WaitForEndOfFrame(); 
+			yield return new WaitForEndOfFrame();
+
+			// get pools count
+			var memoryPoolsCount2 = new List<WeakReference<IMemoryPool>>(StaticMemoryPoolRegistry.Pools).Count;
+
+			// the memory leak
+			Assert.IsEqual(memoryPoolsCount1 - 1, memoryPoolsCount2);
+
+			yield break;
+		}
+
+		class Foo
+		{
+			public string Value
+			{
+				get;
+				private set;
+			}
+
+			public int ResetCount
+			{
+				get; private set;
+			}
+
+			public class Pool : MemoryPool<string, Foo>
+			{
+				protected override void Reinitialize(string value, Foo foo)
+				{
+					foo.Value = value;
+					foo.ResetCount++;
+				}
+			}
+		}
+
+		void TestAbstractMemoryPoolInternal()
+		{
+			PreInstall();
+			Container.BindMemoryPool<IBar, BarPool>()
+				.WithInitialSize(3).To<Bar>().NonLazy();
+
+			PostInstall();
+		}
+
+		public interface IBar
+		{
+		}
+
+		public class Bar : IBar
+		{
+		}
+
+		public class BarPool : MemoryPool<int, IBar>
+		{
+		}
+
+		public class FooInstallerScript : MonoInstaller<FooInstallerScript>
+		{
+			public override void InstallBindings()
+			{
+				Container.BindMemoryPool<Foo, Foo.Pool>();
+			}
+		}
+	}
+}
+