everything-claude-code-mobile: Skill for Claude Code

iOS Testing

Testing patterns for Swift and SwiftUI apps.

Unit Tests

Basic Unit Test

import XCTest
@testable import MyApp

class UserViewModelTests: XCTestCase {
    var sut: UserViewModel!
    var mockService: MockUserService!

    override func setUp() {
        super.setUp()
        mockService = MockUserService()
        sut = UserViewModel(service: mockService)
    }

    override func tearDown() {
        sut = nil
        mockService = nil
        super.tearDown()
    }

    func testLoadUsers_whenSuccessful_populatesUsers() async throws {
        // Given
        let expectedUsers = [User.mock1, User.mock2]
        mockService.usersToReturn = expectedUsers

        // When
        await sut.loadUsers()

        // Then
        XCTAssertEqual(sut.users, expectedUsers)
        XCTAssertFalse(sut.isLoading)
        XCTAssertNil(sut.errorMessage)
    }

    func testLoadUsers_whenFailure_setsErrorMessage() async throws {
        // Given
        mockService.shouldThrowError = true

        // When
        await sut.loadUsers()

        // Then
        XCTAssertTrue(sut.users.isEmpty)
        XCTAssertNotNil(sut.errorMessage)
    }
}

Mocking

// ✅ Protocol-based mocking
protocol UserServiceProtocol {
    func getUsers() async throws -> [User]
}

class MockUserService: UserServiceProtocol {
    var usersToReturn: [User] = []
    var shouldThrowError = false
    var getUsersCalled = false

    func getUsers() async throws -> [User] {
        getUsersCalled = true
        if shouldThrowError {
            throw NetworkError.noConnection
        }
        return usersToReturn
    }
}

// ✅ Verify method calls
func testRefreshButton_callsService() async {
    // When
    await sut.refresh()

    // Then
    XCTAssertTrue(mockService.getUsersCalled)
}

Async Testing

func testAsyncOperation_completesSuccessfully() async throws {
    // Given
    let expectation = expectation(description: "Async completes")

    // When
    Task {
        await sut.asyncOperation()
        expectation.fulfill()
    }

    // Then
    await fulfillment(of: [expectation], timeout: 1.0)
}

// ✅ Swift async/await
func testAsyncFetch_returnsUsers() async throws {
    let users = try await sut.fetchUsers()
    XCTAssertFalse(users.isEmpty)
}