add object pool tests

Author: lucasteles

tests/Backdash.Tests/Specs/Unit/Data/ObjectPoolTests.cs

@@ -0,0 +1,127 @@
+using Backdash.Data;
+
+namespace Backdash.Tests.Specs.Unit.Data;
+
+public class ObjectPoolTests
+{
+    [Fact]
+    public void ShouldRentAndReturnSameObject()
+    {
+        var sut = ObjectPool.Create<TestObj>();
+
+        var value = sut.Rent();
+        sut.Count.Should().Be(0);
+
+        sut.Return(value);
+        sut.Count.Should().Be(1);
+
+        var value2 = sut.Rent();
+        sut.Count.Should().Be(0);
+
+        value2.Should().BeSameAs(value);
+    }
+
+    [Fact]
+    public void ShouldNotReturnSameObjectTwice()
+    {
+        var sut = ObjectPool.Create<TestObj>();
+        var value = sut.Rent();
+        sut.Count.Should().Be(0);
+
+        sut.Return(value);
+        sut.Return(value);
+        sut.Count.Should().Be(1);
+    }
+
+    [Fact]
+    public void ShouldCallCreateAndReturnFunction()
+    {
+        ObjectPool<TestObj> sut = new(
+            () => new()
+            {
+                Value = 1,
+                Returned = false,
+            },
+            obj =>
+            {
+                obj.Value = 0;
+                obj.Returned = true;
+            }
+        );
+
+        var value = sut.Rent();
+
+        value.Should().BeEquivalentTo(new
+        {
+            Value = 1,
+            Returned = false,
+        });
+
+        value.Value = 2;
+        sut.Return(value);
+
+        value.Should().BeEquivalentTo(new
+        {
+            Value = 0,
+            Returned = true,
+        });
+    }
+
+    [Fact]
+    public void ShouldAddMoreThanCapacity()
+    {
+        const int capacity = 5;
+        var sut = ObjectPool.Create<TestObj>(capacity);
+        FillPool(sut, capacity * 2);
+        sut.Count.Should().Be(capacity);
+    }
+
+    [Fact]
+    public void ShouldClear()
+    {
+        var sut = ObjectPool.Create<TestObj>();
+        FillPool(sut, 5);
+
+        sut.Count.Should().Be(5);
+        sut.Clear();
+        sut.Count.Should().Be(0);
+    }
+
+    [Fact]
+    public void ShouldDisposeItems()
+    {
+        var sut = ObjectPool.Create<TestObjDisposable>();
+        TestObjDisposable[] rents =
+        [
+            sut.Rent(),
+            sut.Rent(),
+            sut.Rent(),
+        ];
+
+        foreach (var r in rents)
+            sut.Return(r);
+
+        sut.Count.Should().Be(rents.Length);
+        sut.Dispose();
+        rents.Should().AllSatisfy(r => r.Disposed.Should().BeTrue());
+    }
+
+    static void FillPool(ObjectPool<TestObj> sut, int count) =>
+        Enumerable.Repeat<object?>(null, count)
+            .Select(_ => sut.Rent())
+            .ToList()
+            .ForEach(x => sut.Return(x));
+
+    [Serializable]
+    sealed class TestObj
+    {
+        public int Value { get; set; }
+        public bool Returned { get; set; }
+    }
+
+    sealed class TestObjDisposable : IDisposable
+    {
+        public bool Disposed { get; private set; }
+        public void Dispose() => Disposed = true;
+    }
+}