UserDefaults Mockable

UserDefaultsService.swift

import Foundation

protocol UserDefaultsDelegate: class {
    func theObject(forKey key: String) -> Any?
    func setTheObject(_ object: Any, forKey key: String)
    func removeTheObject(forKey key: String)
    func synchronizeAll()
}

class UserDefaultsService: NSObject {

    static let shared = UserDefaultsService()
    weak var delegate: UserDefaultsDelegate?

    override init() {
        super.init()
        delegate = UserDefaults.standard
    }

    func get<T>(_ typeOf: T.Type, forKey key: String) -> T? {
        return delegate?.theObject(forKey: key) as? T
    }

    func set<T>(_ value: T, forKey key: String) {
        delegate?.setTheObject(value, forKey: key)
    }

    func removeObject(forKey key: String) {
        delegate?.removeTheObject(forKey: key)
    }

    func synchronize() {
        delegate?.synchronizeAll()
    }
}

extension UserDefaults: UserDefaultsDelegate {

    func theObject(forKey key: String) -> Any? {
        return self.object(forKey: key)
    }

    func setTheObject(_ object: Any, forKey key: String) {
        self.set(object, forKey: key)
    }

    func removeTheObject(forKey key: String) {
        self.removeObject(forKey: key)
    }

    func synchronizeAll() {
        self.synchronize()
    }
}