Dependency Inversion Principle

CodeSampleDIP.swift

protocol NetworkLayerType {
    func request() -> [String]
}


class ViewController {
    var models: [String]!
    let networkLayer: NetworkLayerType
    init(networkLayer: NetworkLayerType) {
        self.networkLayer = networkLayer
    }
    
    func viewDidLoad() {
        models = networkLayer.request()
        debugPrint(models.count)
    }
}

class NetworkLayer: NetworkLayerType {
    func request() -> [String] {
        // Example this is real network request
        return ["product1", "product2", "product3"]
    }
}

class MockNetworkLayer: NetworkLayerType {
    func request() -> [String] {
        // Example Fake data
         return ["FakeProduct1", "FakeProduct2", "FakeProduct3"]
    }
}

//let networkLayer = NetworkLayer()
//
//
//let viewController = ViewController(networkLayer: networkLayer)
//viewController.viewDidLoad()



let mockNetworkLayer = MockNetworkLayer()
let viewController = ViewController(networkLayer: mockNetworkLayer)
viewController.viewDidLoad()