@iOSDC

1. Unit Test 最後⼀一哩路路
Hokila Jan
iOSDC

2. 2
Hokita Jan
since iOS 4
5 years in ObjC, 2 years in Swift
video streaming / DRM / IAP
Unit Test / Refactor / AB Test

3. 3
什什麼是 Unit Test
ModuleInput Output

4. 3
什什麼是 Unit Test
ModuleInput Output
固定 input ，經過 Module 處理理，檢查 Output

5. 4
為什什麼沒有寫 Unit Test - 常⾒見見說法
feature 都來來不及做了了，哪有時間寫
我們家有 QA
有 UI Test 啊

6. 5
為什什麼沒有寫 Unit Test - 實際上
不會寫
不會控制 Input (API , 不是⾃自⼰己寫的 SDK)
ViewController 超級無敵⼤大，看到就肚爛

7. 實際案例例
login View Controller

8. 7
LoginViewController
login API
AccountKit login API
Facebook login API
save Token after login success
tracking event
set User Info

9. 8
問題 - dependency 太多
login API，成功 or 失敗
facebook / AccountKit SDK ⾏行行為
是否有存下 AccessToken
User 資料是不是該有的都有 (UserID , MemberShip)
該有的 tracking 是不是有送
login 時
login 後

10. 9
UI ViewController
Login API
Facebook
AccessToken
ViewController 功能太多
無法測試
User
Amplitude

11. Step 1. 拆出 login manager

12. Step 1. 拆出 login manager
不知道在幹嘛的 module 叫 manager 就對了了

13. 11
class LoginManager{
weak var delegate:LoginManagerDelegate?
func loginFB()
func loginAccountKit()
}

14. 11
protocol LoginManagerDelegate:class{
func loginStart()
func loginSuccess(status:LoginStatus)
func loginFail(json:[String:Any]?,error:NSError?)
}
class LoginManager{
weak var delegate:LoginManagerDelegate?
func loginFB()
func loginAccountKit()
}

15. 12
class LoginController: BaseViewController{
func touchFBlogin(_ sender: AnyObject) {
self.loginManager.loginFB()
}
func touchAClogin(_ sender: AnyObject){
self.loginManager.loginAccountKit()
}
}
extension LoginViewController:LoginManagerDelegate{
func loginStart(){ //show indicator }
func loginFail(json:[String:Any]?,error:NSError?){ //error handling}
func loginSuccess(status:LoginStatus){ //success flow }
}

16. 13
LoginViewController LoginManager
login API
AccountKit login API
Facebook login API
save Token after login success
tracking event
set User Info
login start
login fail handler
login success handler

17. 13
LoginViewController LoginManager
login API
AccountKit login API
Facebook login API
save Token after login success
tracking event
set User Info
login start
login fail handler
login success handler

18. 13
LoginViewController LoginManager
login API
AccountKit login API
Facebook login API
save Token after login success
tracking event
set User Info
login start
login fail handler
login success handler

19. 14
Login
Manager
login API
AccountKit login API
Facebook login API
LoginManagerDelegate
save Token
tracking event
set User Info

20. Step 2. dependency injection

21. 16
UI ViewController
Login API
Facebook
AccessToken
User
Amplitude

22. 16
UI ViewController
Login API
Facebook
AccessToken
User
Amplitude
Login API
Delegate

23. 17
模擬 login API ⾏行行為
protocol LoginAPIDelegate {
func loginToken(token:String?,callback:@escaping loginAPICompletion)
}
17

24. 17
模擬 login API ⾏行行為
protocol LoginAPIDelegate {
func loginToken(token:String?,callback:@escaping loginAPICompletion)
}
extension API:LoginAPIDelegate{
func loginToken(token:String?,callback:@escaping loginAPICompletion{
// call real API here
}
}
17

25. 17
模擬 login API ⾏行行為
protocol LoginAPIDelegate {
func loginToken(token:String?,callback:@escaping loginAPICompletion)
}
class MockLoginAPI:LoginAPIDelegate {
func loginToken(token:String?,callback:@escaping loginAPICompletion {
//use mock response here
}
}
extension API:LoginAPIDelegate{
func loginToken(token:String?,callback:@escaping loginAPICompletion{
// call real API here
}
}
17

26. 18
模擬 Facebook SDK response ⾏行行為
protocol FBLoginManagerDelegate {
var currentAccessToken:String? { get }
}
class FBLoginManager:FBLoginManagerDelegate {
var currentAccessToken:String? {
return FBSDKAccessToken.current()?.tokenString
}
}
class MockFBLogin:FBLoginManagerDelegate {
var currentAccessToken: String?
}

27. 19
class LoginManager{
weak var delegate:LoginManagerDelegate?
private var loginAPI:LoginAPIDelegate
private let accountKit:AccountKitDelegate
private let fb:FBLoginManagerDelegate
init(api:LoginAPIDelegate = API.shareInstance,
ac:AccountKitDelegate = AKFAccountKit(responseType: .accessToken),
fblogin:FBLoginManagerDelegate = FBLoginManager()) {
self.loginAPI = api
self.accountKit = ac
self.fb = fblogin
}
}
Real Instance

28. 20
class MockLoginAPI:LoginAPIDelegate {
func loginToken(token:String?,callback:@escaping loginAPICompletion {
//use mock response here
}
}
Mock Login API

29. 20
class MockLoginAPI:LoginAPIDelegate {
func loginToken(token:String?,callback:@escaping loginAPICompletion {
//use mock response here
}
}
Mock Login API
class MockLoginAPI:LoginAPIDelegate {
var loginCallback:(LoginStatus,[String:Any]?, AccessToken?, NSError?)
func loginToken(token:String?,callback:@escaping loginAPICompletion {
callback(loginCallback.0,loginCallback.1,
loginCallback.2,loginCallback.3)
}
}

30. 21
class MockFBLogin:FBLoginManagerDelegate {
var currentAccessToken: String?
}
Mock FB SDK

31. Step 3. write test

32. 23
class KTLoginManagerTests:KKTVTests {
private var mockLoginAPI = MockLoginAPI()
private var mockAC = MockAccountKit()
private var mockFBLogin = MockFBLogin()
private var mockAccessTokenManager = MockAccessTokenManager()
private var mockTracker = MockTracker()
private var mockLoginVC = MockLoginVC()
private var mockUser = MockUser()
}

33. 23
class KTLoginManagerTests:KKTVTests {
private var mockLoginAPI = MockLoginAPI()
private var mockAC = MockAccountKit()
private var mockFBLogin = MockFBLogin()
private var mockAccessTokenManager = MockAccessTokenManager()
private var mockTracker = MockTracker()
private var mockLoginVC = MockLoginVC()
private var mockUser = MockUser()
}
override func setUp() {
super.setUp()
// rest all mock object
}

34. 24
func testFBloginSuccess() {
//1.prepare input
mockFBLogin.currentAccessToken = "123456789"
let loginJSON = loadData(fileName: "loginSuccess", type: "json")
mockLoginAPI.loginCallback = (.loginSuccess,loginJSON,authToken,nil)

35. 24
func testFBloginSuccess() {
//1.prepare input
mockFBLogin.currentAccessToken = "123456789"
let loginJSON = loadData(fileName: "loginSuccess", type: "json")
mockLoginAPI.loginCallback = (.loginSuccess,loginJSON,authToken,nil)
//2.Compose Login Manager
loginManager = KTLoginManager(api: mockLoginAPI,
fblogin: mockFBLogin)
loginManager.delegate = mockLoginVC

36. 24
func testFBloginSuccess() {
//1.prepare input
mockFBLogin.currentAccessToken = "123456789"
let loginJSON = loadData(fileName: "loginSuccess", type: "json")
mockLoginAPI.loginCallback = (.loginSuccess,loginJSON,authToken,nil)
//2.Compose Login Manager
loginManager = KTLoginManager(api: mockLoginAPI,
fblogin: mockFBLogin)
loginManager.delegate = mockLoginVC
//3.trigger login
loginManager.loginFB()
//4.Verify output
……..
}

37. 25
func testFBloginSuccess() {
……..
//4.Verify output
XCTAssertTrue(mockLoginVC.isLoginSuccess)
XCTAssertNotNil(mockAccessTokenManager.lastAccessToken)
XCTAssertEqual(mockUser.info.memberShip, .premium)
XCTAssertNotNil(mockUser.info.userID)
XCTAssertEqual(mockTracker.lastStatus, .loginSuccess)
XCTAssertEqual(mockTracker.lastLoginType, .facebook)
XCTAssertNotNil(mockTracker.lastLoginUserInfo.userID)
}

38. 26
什什麼是 Unit Test
ModuleInput Output

39. 26
什什麼是 Unit Test
ModuleInput Output
固定 input ，經過 Module 處理理，檢查 Output

40. 27
UI
Presenter
Login API
provider
Facebook
AccessToken
Manager
LoginManager
Login
API
User
Tracking
manager
AccessToken
Delegate
Facebook
Delegate
User info
User setting
Amplitude
Action
原本的 View Controller 剩餘功能
Access
Token

41. 27
UI
Presenter
Login API
provider
Facebook
AccessToken
Manager
Login API
Delegate
LoginManager
Login
API
User
Tracking
manager
AccessToken
Delegate
Facebook
Delegate
User info
User setting
Amplitude
Action
原本的 View Controller 剩餘功能
Access
Token

42. 27
UI
Presenter
Login API
provider
Facebook
AccessToken
Manager
Login API
Delegate
LoginManager
User
Tracking
manager
AccessToken
Delegate
Facebook
Delegate
User info
User setting
Amplitude
Action
原本的 View Controller 剩餘功能
Access
Token

43. dependency injection ⼩小技巧

44. inject 的 module 太多，不確定有沒有漏

45. 30
class LoginManager{
static let shareInstance = LoginManager()
weak var delegate:LoginManagerDelegate?
private var loginAPI:LoginAPIDelegate
private let accountKit:AccountKitDelegate
private let fb:FBLoginManagerDelegate
init(api:LoginAPIDelegate = API.shareInstance,
ac:AccountKitDelegate = AKFAccountKit(responseType: .accessToken),
fblogin:FBLoginManagerDelegate = FBLogInManager()) {
self.loginAPI = api
self.accountKit = ac
self.fb = fblogin
}
}
Real Instance

46. 31
struct LoginManagerInject{
var loginAPI:KTLoginAPIDelegate = KTAPI.shareInstance
var accountKit:KTAccountKitDelegate = AKFAccountKit(responseType: .accessTok
var fb:KTFBLoginManagerDelegate = FBLogInManager()
}

47. 31
struct LoginManagerInject{
var loginAPI:KTLoginAPIDelegate = KTAPI.shareInstance
var accountKit:KTAccountKitDelegate = AKFAccountKit(responseType: .accessTok
var fb:KTFBLoginManagerDelegate = FBLogInManager()
}
class LoginManager{
static let shareInstance = LoginManager()
weak var delegate:LoginManagerDelegate?
private let inject:LoginManagerInject
init(inject:LoginManagerInject = LoginManagerInject() ){
self.inject = inject
}
}

48. 31
struct LoginManagerInject{
var loginAPI:KTLoginAPIDelegate = KTAPI.shareInstance
var accountKit:KTAccountKitDelegate = AKFAccountKit(responseType: .accessTok
var fb:KTFBLoginManagerDelegate = FBLogInManager()
}
self.loginAPI
class LoginManager{
static let shareInstance = LoginManager()
weak var delegate:LoginManagerDelegate?
private let inject:LoginManagerInject
init(inject:LoginManagerInject = LoginManagerInject() ){
self.inject = inject
}
}

49. 31
struct LoginManagerInject{
var loginAPI:KTLoginAPIDelegate = KTAPI.shareInstance
var accountKit:KTAccountKitDelegate = AKFAccountKit(responseType: .accessTok
var fb:KTFBLoginManagerDelegate = FBLogInManager()
}
self.inject.loginAPIself.loginAPI
class LoginManager{
static let shareInstance = LoginManager()
weak var delegate:LoginManagerDelegate?
private let inject:LoginManagerInject
init(inject:LoginManagerInject = LoginManagerInject() ){
self.inject = inject
}
}

50. inject init function

51. 33
User
UserInfo
UserSetting
User Info save in memory
Ex:User ID, Member Ship
User Setting save in NSUserDefault
Ex:IsShowXXPage
When UserInfo change , some UserSetting Variable also change
Requirement
AppDelegate

52. 34
User
UserInfo
UserSetting
fileprivate(set) var memberShip:MemberShip = .unassign {
willSet(newValue){
//change from premium to expire
if self.memberShip == .premium && newValue == .expired {
shareAppDelegate.user.setting.hasShowExpireNotice = false
}
}
}

53. 35
class UserInfo {
private var userSetting:UserSettingDelegate
init(userSetting:UserSettingDelegate = shareAppDelegate.user.setting){
self.userSetting = userSetting
}
}
User UserInfoAppDelegat
User UserSettingAppDelegate

54. 36
class UserInfo {
private var userSetting:UserSettingDelegate
init(userSetting:UserSettingDelegate = shareAppDelegate.user.setting){
self.userSetting = userSetting
}
}
User UserInfoAppDelegat
User
UserSetting
AppDelegate
UserInfo

55. 37
class UserInfo {
private var userSetting:UserSettingDelegate
init(userSetting:UserSettingDelegate = shareAppDelegate.user.setting){
self.userSetting = userSetting
}
}
User UserInfoAppDelegat
User
UserSetting
AppDelegate
UserInfo
User UserSettingAppDelegate

56. 38
class UserInfo:{
private var injectFunc:()->UserSetting
private var setting:UserSetting {
return self.injectFunc()
}
init(injectFunc:@escaping ()->UserSetting =
{return shareDelegate.user.setting}){
self.injectFunc = injectFunc
}
}

57. 38
class UserInfo:{
private var injectFunc:()->UserSetting
private var setting:UserSetting {
return self.injectFunc()
}
init(injectFunc:@escaping ()->UserSetting =
{return shareDelegate.user.setting}){
self.injectFunc = injectFunc
}
}
stored property

58. 38
class UserInfo:{
private var injectFunc:()->UserSetting
private var setting:UserSetting {
return self.injectFunc()
}
init(injectFunc:@escaping ()->UserSetting =
{return shareDelegate.user.setting}){
self.injectFunc = injectFunc
}
}
stored property
computed property

59. 38
class UserInfo:{
private var injectFunc:()->UserSetting
private var setting:UserSetting {
return self.injectFunc()
}
init(injectFunc:@escaping ()->UserSetting =
{return shareDelegate.user.setting}){
self.injectFunc = injectFunc
}
}
self.setting
stored property
computed property

60. 39
殘酷的事實
新創公司的開發模式
花了了⼀一倍的時間寫 Feature，但是邏輯都混在⼀一起沒有拆 module
要 refactor + 補 Unit Test 的時間，跟原本做 Feature 的時間⼀一樣
猶豫

61. 40
循環
寫了了⼀一個 Feature，但是邏輯都混在⼀一起沒有拆 module
要補 Unit Test 好累喔，要 refactor 好危險
不敢動，不知道怎麼拆 module
有了了新 Request
寫了了⼀一個新Feature，但是邏輯都混在⼀一起沒有拆 module
…………….

62. 41
寫 Unit Test 帶來來的好處
• 同樣的 code ⽤用兩兩種思考⽅方式看過
• 重新檢視每個 class 的功能
• ⾃自然⽽而然學會切 module，找出可以共⽤用的商業邏輯
• ⾃自動跑，⼀一次跑完幾百個幾千的 check，令⼈人安⼼心

63. 42
作對事 vs 不要做錯事
• 花了了⼀一個⽉月做了了新 feature ，推出後市場反應平淡
• 花了了5秒不⼩小⼼心改到共⽤用 class 的邏輯，所有 user 受影響
• 做了了⼀一堆 feature ，user 可能會喜歡可能不會喜歡，
但是重要功能出 bug，那就死定了了

64. 43
要怎麼開始？
• 列列出 priority，重要的事要⾺馬上做。⼀一個⽉月後還沒開始做，那就是不重要的事
• 絕對不可以錯的 module + 會⼤大量量 refuse 的 model
• 下次寫新 module 的時候先想 input output
• 祝各位⼯工程師從此過著幸福快樂的⽇日⼦子

65. 44
相關閱讀
• wwdc 2017 session 414: Engineering for Testability
• Test-Driven iOS Development with Swift 4
• Working Effectively with Legacy Code
• The Art of Unit Testing