LizzieStudeneer

class BasketService {
    private let repository: Repository<Article>

    init(repository: Repository<Article>) {
        self.repository = repository
    }

    func addAllArticles(to basket: Basket) {
        let allArticles = repository.getAll()
        basket.articles.append(contentsOf: allArticles)

LizzieStudeneer

class BasketServiceTests: XCTestCase {
    func testAddAllArticles() {
        let expectedArticle = Article(title: "Article 1")
        let mockRepository = MockRepository<Article>(objects: [expectedArticle])
        let basketService = BasketService(repository: mockRepository)
        let basket = Basket()

        basketService.addAllArticles(to: basket)

        XCTAssertEqual(basket.articles.count, 1)

LizzieStudeneer

class BasketViewController: UIViewController {
    var basketService: BasketService! = nil
}

let basketViewController = BasketViewController()
basketViewController.basketService = BasketService()

LizzieStudeneer

class BasketViewController: UIViewController {
    var basketService: BasketService = BasketService()
}

LizzieStudeneer

protocol BasketFactory {
    func makeBasketService() -> BasketService
    func makeBasketViewController() -> BasketViewController
}

LizzieStudeneer

class DefaultBasketFactory: BasketFactory {

    func makeBasketService() -> BasketService {
        let repository = makeArticleRepository()
        return BasketService(repository: repository)
    }

    func makeBasketViewController() -> BasketViewController {
        let basketViewController = BasketViewController()
        basketViewController.basketService = makeBasketService()

LizzieStudeneer

let basketViewController = factory.makeBasketViewController()

LizzieStudeneer

protocol Resolver {
    func resolve<ServiceType>(_ type: ServiceType.Type) -> ServiceType
}

LizzieStudeneer

let resolver: Resolver = ...
let instance = resolver.resolve(SomeProtocol.self)

LizzieStudeneer

protocol ServiceFactory {
    associatedtype ServiceType
    func resolve(_ resolver: Resolver) -> ServiceType
}