public void SuppliesTransientInstancesWhenExceedingCapacity()
{
// Arrange
var stackObjectPool = new StackObjectPool <object>(1, () => new object());
// Act 1: Returns distinct instances beyond capacity
var instance1 = stackObjectPool.Get();
var instance2 = stackObjectPool.Get();
var instance3 = stackObjectPool.Get();
Assert.NotNull(instance1);
Assert.NotNull(instance2);
Assert.NotNull(instance3);
Assert.Equal(3, new[] { instance1, instance2, instance3 }.Distinct().Count());
// Act 2: Can return all instances, including transient ones
stackObjectPool.Return(instance3);
stackObjectPool.Return(instance2);
stackObjectPool.Return(instance1);
// Act 3: Reuses only the non-transient instances
var instance1b = stackObjectPool.Get();
var instance2b = stackObjectPool.Get();
Assert.Same(instance1, instance1b);
Assert.NotSame(instance2b, instance2);
Assert.Equal(4, new[] { instance1, instance2, instance3, instance2b }.Distinct().Count());
}
public void CanReturnInstances()
{
// Arrange
var stackObjectPool = new StackObjectPool <object>(10, () => new object());
var instance1 = stackObjectPool.Get();
var instance2 = stackObjectPool.Get();
// Act/Assert
// No exception means success
stackObjectPool.Return(instance2);
stackObjectPool.Return(instance1);
}
public void CannotReturnWhenEmpty()
{
// Arrange
var stackObjectPool = new StackObjectPool <object>(10, () => new object());
// Act/Assert
var ex = Assert.Throws <InvalidOperationException>(() =>
{
stackObjectPool.Return(new object());
});
Assert.Equal("There are no outstanding instances to return.", ex.Message);
}
public void CanGetInstances()
{
// Arrange
var stackObjectPool = new StackObjectPool <object>(10, () => new object());
// Act
var instance1 = stackObjectPool.Get();
var instance2 = stackObjectPool.Get();
// Assert
Assert.NotNull(instance1);
Assert.NotNull(instance2);
Assert.NotSame(instance1, instance2);
}
public void CannotReturnMismatchingTrackedItem()
{
// Arrange
var stackObjectPool = new StackObjectPool <object>(10, () => new object());
var instance1 = stackObjectPool.Get();
var instance2 = stackObjectPool.Get();
// Act/Assert
var ex = Assert.Throws <ArgumentException>(() =>
{
stackObjectPool.Return(instance1);
});
Assert.Equal("Attempting to return wrong pooled instance. Get/Return calls must form a stack.", ex.Message);
}
public void ReusesInstancesInPoolUpToCapacity()
{
// Arrange
var stackObjectPool = new StackObjectPool <object>(10, () => new object());
var instance1 = stackObjectPool.Get();
var instance2 = stackObjectPool.Get();
stackObjectPool.Return(instance2);
stackObjectPool.Return(instance1);
// Act
var instance1b = stackObjectPool.Get();
var instance2b = stackObjectPool.Get();
var instance3 = stackObjectPool.Get();
// Assert
Assert.Same(instance1, instance1b);
Assert.Same(instance2, instance2b);
Assert.NotNull(instance3);
Assert.NotSame(instance1, instance3);
Assert.NotSame(instance2, instance3);
}