Comprehensive mobile app testing strategies for iOS and Android. Covers unit tests, UI tests, integration tests, performance testing, and test automation with Detox, Appium, and XCTest.
Implement comprehensive testing strategies for mobile applications including unit tests, UI tests, integration tests, and performance testing.
// Unit test with Jest
import { calculate } from '../utils/math';
describe('Math utilities', () => {
test('should add two numbers', () => {
expect(calculate.add(2, 3)).toBe(5);
});
test('should handle negative numbers', () => {
expect(calculate.add(-2, 3)).toBe(1);
});
});
// Component unit test
import React from 'react';
import { render, screen } from '@testing-library/react-native';
import { UserProfile } from '../components/UserProfile';
describe('UserProfile Component', () => {
test('renders user name correctly', () => {
const mockUser = { id: '1', name: 'John Doe', email: '[email protected]' };
render(<UserProfile user={mockUser} />);
expect(screen.getByText('John Doe')).toBeTruthy();
});
test('handles missing user gracefully', () => {
render(<UserProfile user={null} />);
expect(screen.getByText(/no user data/i)).toBeTruthy();
});
});
// E2E Testing with Detox
describe('Login Flow E2E Test', () => {
beforeAll(async () => {
await device.launchApp();
});
beforeEach(async () => {
await device.reloadReactNative();
});
it('should login successfully with valid credentials', async () => {
await waitFor(element(by.id('emailInput')))
.toBeVisible()
.withTimeout(5000);
await element(by.id('emailInput')).typeText('[email protected]');
await element(by.id('passwordInput')).typeText('password123');
await element(by.id('loginButton')).multiTap();
await waitFor(element(by.text('Home Feed')))
.toBeVisible()
.withTimeout(5000);
});
it('should show error with invalid credentials', async () => {
await element(by.id('emailInput')).typeText('[email protected]');
await element(by.id('passwordInput')).typeText('wrongpass');
await element(by.id('loginButton')).multiTap();
await waitFor(element(by.text(/invalid credentials/i)))
.toBeVisible()
.withTimeout(5000);
});
it('should navigate between tabs', async () => {
await element(by.id('profileTab')).tap();
await waitFor(element(by.text('Profile')))
.toBeVisible()
.withTimeout(2000);
await element(by.id('homeTab')).tap();
await waitFor(element(by.text('Home Feed')))
.toBeVisible()
.withTimeout(2000);
});
});
import XCTest
@testable import MyApp
class UserViewModelTests: XCTestCase {
var viewModel: UserViewModel!
var mockNetworkService: MockNetworkService!
override func setUp() {
super.setUp()
mockNetworkService = MockNetworkService()
viewModel = UserViewModel(networkService: mockNetworkService)
}
func testFetchUserSuccess() async {
let expectedUser = User(id: UUID(), name: "John", email: "[email protected]")
mockNetworkService.mockUser = expectedUser
await viewModel.fetchUser(id: expectedUser.id)
XCTAssertEqual(viewModel.user?.name, "John")
XCTAssertNil(viewModel.errorMessage)
XCTAssertFalse(viewModel.isLoading)
}
func testFetchUserFailure() async {
mockNetworkService.shouldFail = true
await viewModel.fetchUser(id: UUID())
XCTAssertNil(viewModel.user)
XCTAssertNotNil(viewModel.errorMessage)
XCTAssertFalse(viewModel.isLoading)
}
}
class MockNetworkService: NetworkService {
var mockUser: User?
var shouldFail = false
override func fetch<T: Decodable>(
_: T.Type,
from endpoint: String
) async throws -> T {
if shouldFail {
throw NetworkError.unknown
}
return mockUser as! T
}
}
// UI Test
class LoginUITests: XCTestCase {
override func setUp() {
super.setUp()
continueAfterFailure = false
XCUIApplication().launch()
}
func testLoginFlow() {
let app = XCUIApplication()
let emailTextField = app.textFields["emailInput"]
let passwordTextField = app.secureTextFields["passwordInput"]
let loginButton = app.buttons["loginButton"]
emailTextField.tap()
emailTextField.typeText("[email protected]")
passwordTextField.tap()
passwordTextField.typeText("password123")
loginButton.tap()
let homeText = app.staticTexts["Home Feed"]
XCTAssertTrue(homeText.waitForExistence(timeout: 5))
}
func testNavigationBetweenTabs() {
let app = XCUIApplication()
let profileTab = app.tabBars.buttons["Profile"]
let homeTab = app.tabBars.buttons["Home"]
profileTab.tap()
XCTAssertTrue(app.staticTexts["Profile"].exists)
homeTab.tap()
XCTAssertTrue(app.staticTexts["Home"].exists)
}
}
@RunWith(AndroidJUnit4::class)
class UserViewModelTest {
private lateinit var viewModel: UserViewModel
private val mockApiService = mock<ApiService>()
@Before
fun setUp() {
viewModel = UserViewModel(mockApiService)
}
@Test
fun fetchUserSuccess() = runTest {
val expectedUser = User("1", "John", "[email protected]")
`when`(mockApiService.getUser("1")).thenReturn(expectedUser)
viewModel.fetchUser("1")
assertEquals(expectedUser.name, viewModel.user.value?.name)
assertEquals(null, viewModel.errorMessage.value)
}
@Test
fun fetchUserFailure() = runTest {
`when`(mockApiService.getUser("1"))
.thenThrow(IOException("Network error"))
viewModel.fetchUser("1")
assertEquals(null, viewModel.user.value)
assertNotNull(viewModel.errorMessage.value)
}
}
// UI Test with Espresso
@RunWith(AndroidJUnit4::class)
class LoginActivityTest {
@get:Rule
val activityRule = ActivityScenarioRule(LoginActivity::class.java)
@Test
fun testLoginWithValidCredentials() {
onView(withId(R.id.emailInput))
.perform(typeText("[email protected]"))
onView(withId(R.id.passwordInput))
.perform(typeText("password123"))
onView(withId(R.id.loginButton))
.perform(click())
onView(withText("Home"))
.check(matches(isDisplayed()))
}
@Test
fun testLoginWithInvalidCredentials() {
onView(withId(R.id.emailInput))
.perform(typeText("[email protected]"))
onView(withId(R.id.passwordInput))
.perform(typeText("wrongpassword"))
onView(withId(R.id.loginButton))
.perform(click())
onView(withText(containsString("Invalid credentials")))
.check(matches(isDisplayed()))
}
@Test
fun testNavigationBetweenTabs() {
onView(withId(R.id.profileTab)).perform(click())
onView(withText("Profile")).check(matches(isDisplayed()))
onView(withId(R.id.homeTab)).perform(click())
onView(withText("Home")).check(matches(isDisplayed()))
}
}
import XCTest
class PerformanceTests: XCTestCase {
func testListRenderingPerformance() {
let viewModel = ItemsViewModel()
viewModel.items = (0..<1000).map { i in
Item(id: UUID(), title: "Item \(i)", price: Double(i))
}
measure {
_ = viewModel.items.filter { $0.price > 50 }
}
}
func testNetworkResponseTime() {
let networkService = NetworkService()
measure {
let expectation = XCTestExpectation(description: "Fetch user")
Task {
do {
_ = try await networkService.fetch(User.self, from: "/users/test")
expectation.fulfill()
} catch {
XCTFail("Network request failed")
}
}
wait(for: [expectation], timeout: 10)
}
}
}