Testing — XCTest

Darsliklar (Tutorials)

Testing — XCTest & Swift Testing — To'liq Darslik

Mundarija

1. Nega test yozish kerak?
2. Testing piramidasi
3. XCTest asoslari (setUp, tearDown, Assert)
4. Unit Test yozish (ViewModel testlash)
5. Mocking va Stubbing (Protocol-based)
6. Async/Await funksiyalarini testlash
7. UI Testing (XCUITest)
8. Swift Testing — Yangi framework (iOS 18+)
9. TDD (Test Driven Development)
10. Code Coverage (80% maqsad)
11. Real misol: Login ViewModel test
12. Xulosa

1. Nega test yozish kerak? {#motivatsiya}

"Mening kodim ishlayapti, nega test yozishim kerak?" — bu eng katta xato.

• Xavfsiz Refactoring: Kodni o'zgartirganda boshqa joylar buzilmaganiga ishonch hosil qilish.
• Bug'larni erta aniqlash: Foydalanuvchi xato topishidan oldin uni tuzatish.
• Hujjatlashtirish: Testlar kodingiz qanday ishlashi kerakligini ko'rsatib beradi.

2. Testing piramidasi {#testing-pyramid}

1. Unit Tests (Asos): Eng ko'p va eng tez testlar. Alohida funksiya yoki klassni testlaydi.
2. Integration Tests: Modullar bir-biri bilan qanday ishlashini testlaydi.
3. UI Tests: Ilovani foydalanuvchi kabi ishlatib ko'radi (Eng sekin).

3. XCTest asoslari {#xctest-basic}

XCTest — Apple'ning klassik testing framework'i.

import XCTest

class MathTests: XCTestCase {
    // Har bir testdan oldin ishlaydi
    override func setUp() { super.setUp() }
    
    // Har bir testdan keyin ishlaydi
    override func tearDown() { super.tearDown() }
    
    func testAddition() {
        let result = 2 + 2
        XCTAssertEqual(result, 4, "2+2 to'rtga teng bo'lishi kerak")
    }
}

4. Unit Test yozish (ViewModel testlash) {#unit-testing}

MVVM arxitekturasida biznes logika ViewModel'da bo'ladi, shuning uchun uni testlash juda oson.

func testCounterIncrement() {
    let vm = CounterViewModel()
    vm.increment()
    XCTAssertEqual(vm.count, 1)
}

5. Mocking va Stubbing (Protocol-based) {#mocking}

API dan ma'lumot kelishini kutib o'tirmaymiz. Biz "soxta" (mock) servis yaratamiz.

protocol NetworkService {
    func fetchData() async throws -> [String]
}

class MockService: NetworkService {
    func fetchData() async throws -> [String] {
        return ["Rasm 1", "Rasm 2"] // Doim tayyor natija qaytaradi
    }
}

6. Async/Await funksiyalarini testlash {#async-testing}

Swift 5.5 dan keyin asinxron kodni testlash juda osonlashdi:

func testFetchData() async throws {
    let service = MockService()
    let data = try await service.fetchData()
    XCTAssertFalse(data.isEmpty)
}

7. UI Testing (XCUITest) {#ui-testing}

Ilovani haqiqiy simulyatorda ishga tushirib, tugmalarni bosib ko'radi.

func testLoginFlow() {
    let app = XCUIApplication()
    app.launch()
    
    let emailField = app.textFields["email_field"]
    emailField.tap()
    emailField.typeText("test@mail.com")
    
    app.buttons["login_button"].tap()
    
    XCTAssertTrue(app.staticTexts["Welcome"].exists)
}

8. Swift Testing — Yangi framework (iOS 18+) {#swift-testing}

Apple yangi, zamonaviy va sodda framework chiqardi. #expect macro'si va @Test atributi bilan ishlaydi.

import Testing

@Test func checkMath() {
    let result = 2 + 2
    #expect(result == 4)
}

@Suite struct UserTests {
    @Test(arguments: ["Ali", "Vali"])
    func checkUserNames(name: String) {
        #expect(!name.isEmpty)
    }
}

9. TDD (Test Driven Development) {#tdd}

Avval test yozish, keyin kod yozish.

1. Red: Test yozing (u o'tmaydi — qizil).
2. Green: Test o'tishi uchun eng minimal kodni yozing (yashil).
3. Refactor: Kodni chiroyli qiling.

10. Code Coverage (80% maqsad) {#code-coverage}

Xcode'da "Edit Scheme" → "Test" → "Options" → "Gather Coverage" yoqing. Bu sizga kodingizning necha foizi test bilan qoplanganini ko'rsatadi. Professional ilovalar uchun 80% yaxshi natija.

11. Real misol: Login ViewModel test {#real-loyiha}

Darslikda biz login tugmasini aktiv bo'lishi, hato email kiritilganda error chiqishi va muvaffaqiyatli login jarayonini to'liq testlab chiqamiz.

12. Xulosa {#xulosa}

Test yozadigan dasturchi — professional dasturchi hisoblanadi.

• Unit test lardan boshlang.
• ViewModel dagi biznes logikani har doim testlang.
• Swift Testing framework'ini o'rganishni boshlang (kelajak shunda).

Vazifa: O'zingizning kichik funksiyangiz (masalan, yoshni hisoblovchi) uchun 3 ta Unit Test yozing! 🧪