public void should_correctly_expand_for_new_entities() { var startingSize = 10; var expectedSize = 20; var fakeComponentTypes = new Dictionary <Type, int> { { typeof(TestComponentOne), 0 }, { typeof(TestComponentTwo), 1 }, { typeof(TestComponentThree), 2 } }; var mockComponentLookup = Substitute.For <IComponentTypeLookup>(); mockComponentLookup.GetAllComponentTypes().Returns(fakeComponentTypes); var database = new ComponentDatabase(mockComponentLookup, startingSize); database.AccommodateMoreEntities(expectedSize); Assert.Equal(expectedSize, database.CurrentEntityBounds); Assert.Equal(fakeComponentTypes.Count, database.EntityComponents.Length); Assert.Equal(expectedSize, database.EntityComponents[0].Count); Assert.All(database.EntityComponents, x => x.All(y => y == null)); }