public void GetDefaultShapeCollection_ShouldReturnDefaultObjectInstanceCollection() { IEnumerable <AbstractShape> expectedShapeCollection = new List <AbstractShape>() { new Circle("Nom_1", 12), new Circle("Nom_2", 15), new Triangle("Nom_3", 16) }; ShapeManager shapeManager = new ShapeManager(); ShapeCollection actualShapeCollection = shapeManager.GetDefaultShapeCollection(); Assert.AreEqual(expectedShapeCollection.Count(), actualShapeCollection.Count()); foreach (AbstractShape expectedAbstractShape in expectedShapeCollection) { Assert.IsNotNull(actualShapeCollection.SingleOrDefault <AbstractShape>(x => x.Name == expectedAbstractShape.Name && x.Surface == expectedAbstractShape.Surface)); } }