public void Test()
{
World world = new World();
EntityHandler entityA = world.CreateEntity();
entityA.AddComponent(new TestComponent());
EntityHandler entityB = world.CreateEntity();
entityB.AddComponent(new TestComponent());
GameSystem system = new TestSystem(world);
Assert.IsTrue(entityA.GetComponent <TestComponent>().foo == 0, "component default value is wrong");
system.Update();
Assert.IsTrue(entityA.GetComponent <TestComponent>().foo == 1, "component A did not update correctly after system update");
Assert.IsTrue(entityB.GetComponent <TestComponent>().foo == 1, "component B did not update correctly after system update");
system.Update();
Assert.IsTrue(entityA.GetComponent <TestComponent>().foo == 2, "component A did not update correctly after system update");
Assert.IsTrue(entityB.GetComponent <TestComponent>().foo == 2, "component B did not update correctly after system update");
world.RemoveEntity(entityA.entity);
Assert.IsTrue(
!world.GetComponentManager <TestComponent>().EntityHasComponent(entityA.entity),
"entity A was not removed");
system.Update();
Assert.IsTrue(entityB.GetComponent <TestComponent>().foo == 3, "component B did not update correctly after system update");
}