public static void MyClassInitialize(TestContext testContext) { var serviceCollection = new ServiceCollection(); serviceCollection.Transient<IDocumentService>(p => new RepositoryService()); // prepare substitude of IUnitOfWork; var unitOfWork = Substitute.For<IUnitOfWork>(); unitOfWork.When(s => s.SaveChanges()) .Do(c => saveAllChanges = true); serviceCollection.Scoped<IUnitOfWork>(p => unitOfWork); serviceCollection.Scoped(typeof(IRepository<>), typeof(SubRepository<>)); serviceCollection.Update(); }