public void GivenAnElementIsInTheModelWhenUnremoveElementIsCalledThenElementAndItsChildrenAreRestored()
{
DsmElementModel model = new DsmElementModel();
Assert.AreEqual(1, model.GetElementCount());
IDsmElement a = model.AddElement("a", "", null);
Assert.AreEqual(1, a.Id);
IDsmElement a1 = model.AddElement("a1", "eta", a.Id);
Assert.AreEqual(2, a1.Id);
IDsmElement a2 = model.AddElement("a2", "eta", a.Id);
Assert.AreEqual(3, a2.Id);
IDsmElement b = model.AddElement("b", "", null);
Assert.AreEqual(4, b.Id);
IDsmElement b1 = model.AddElement("b1", "etb", b.Id);
Assert.AreEqual(5, b1.Id);
Assert.AreEqual(6, model.GetElementCount());
model.RemoveElement(a.Id);
Assert.AreEqual(3, model.GetElementCount());
List <IDsmElement> rootElementsBefore = model.GetRootElement().Children.OrderBy(x => x.Id).ToList();
Assert.AreEqual(1, rootElementsBefore.Count);
Assert.AreEqual(b, rootElementsBefore[0]);
Assert.AreEqual(1, rootElementsBefore[0].Children.Count);
Assert.AreEqual(b1, rootElementsBefore[0].Children[0]);
model.UnremoveElement(a.Id);
Assert.AreEqual(6, model.GetElementCount());
List <IDsmElement> rootElementsAfter = model.GetRootElement().Children.OrderBy(x => x.Id).ToList();
Assert.AreEqual(2, rootElementsAfter.Count);
Assert.AreEqual(a, rootElementsAfter[0]);
Assert.AreEqual(2, rootElementsAfter[0].Children.Count);
Assert.AreEqual(a1, rootElementsAfter[0].Children[0]);
Assert.AreEqual(a2, rootElementsAfter[0].Children[1]);
Assert.AreEqual(b, rootElementsAfter[1]);
Assert.AreEqual(1, rootElementsAfter[1].Children.Count);
Assert.AreEqual(b1, rootElementsAfter[1].Children[0]);
}
