cometchat-ios-testing

Imported from cometchat/cometchat-skills (skills/cometchat-ios-testing/SKILL.md). Install upstream with npx skills add cometchat/cometchat-skills --skill cometchat-ios-testing. Copyright stays with the author (MIT).

Purpose

Testing patterns for iOS CometChat integrations. XCTest (built-in) for unit + integration; SnapshotTesting (Pointfree) for visual regression; XCUITest for full-flow UI tests on the simulator.

Read these other skills first:

• cometchat-ios-core — init, login, Secrets pattern
• cometchat-ios-components — what each VC does (tests assert against this)
• cometchat-ios-calls/references/callkit-and-pushkit.md — CallKit testing strategy (different from chat)

Ground truth: Official docs: https://www.cometchat.com/docs/ui-kit/ios/overview · Docs MCP: claude mcp add --transport http cometchat-docs https://www.cometchat.com/docs/mcp (or fetch the URL directly without MCP).

• XCTest — https://developer.apple.com/documentation/xctest
• SnapshotTesting — https://github.com/pointfreeco/swift-snapshot-testing

1. Test target structure

A typical iOS project has three targets:

The skill writes to YourAppTests for most assertions; YourAppUITests for full flows.

2. Mocking the SDK via protocols

The CometChat SDKs are class-based with static methods (CometChat.init, CometChat.login). Hard to mock directly. Wrap them in protocols you own:

// Protocols/CometChatService.swift
import CometChatSDK

// CometChatException does NOT conform to Swift's Error, so a throwing
// continuation can't resume with it directly — bridge it through this.
struct CometChatTestError: Error { let message: String }

protocol CometChatServiceProtocol {
  func initialize(appId: String, region: String) async throws
  func login(uid: String, authKey: String) async throws -> User
  func logout() async throws
  func getLoggedInUser() -> User?
  func sendMessage(_ message: TextMessage) async throws -> TextMessage
}

// Production implementation
final class CometChatService: CometChatServiceProtocol {
  func initialize(appId: String, region: String) async throws {
    try await withCheckedThrowingContinuation { (cont: CheckedContinuation<Void, Error>) in
      let settings = AppSettings.AppSettingsBuilder()
        .subscribePresenceForAllUsers()
        .setRegion(region: region)
        .build()
      CometChat.init(appId: appId, appSettings: settings, onSuccess: { _ in
        cont.resume()
      }, onError: { error in
        cont.resume(throwing: CometChatTestError(message: error.errorDescription))
      })
    }
  }

  func login(uid: String, authKey: String) async throws -> User {
    try await withCheckedThrowingContinuation { (cont: CheckedContinuation<User, Error>) in
      CometChat.login(UID: uid, authKey: authKey, onSuccess: { cont.resume(returning: $0) },
                      onError: { cont.resume(throwing: CometChatTestError(message: $0.errorDescription)) })
    }
  }

  // ... etc
}

Inject the protocol via DI:

final class ChatViewController: UIViewController {
  private let service: CometChatServiceProtocol

  init(service: CometChatServiceProtocol = CometChatService()) {
    self.service = service
    super.init(nibName: nil, bundle: nil)
  }
  required init?(coder: NSCoder) { fatalError() }
}

Test with a mock:

// Tests/CometChatServiceMock.swift
final class CometChatServiceMock: CometChatServiceProtocol {
  var initializeCallCount = 0
  var initializeError: Error?
  var loginUser: User?
  var loginError: Error?

  func initialize(appId: String, region: String) async throws {
    initializeCallCount += 1
    if let error = initializeError { throw error }
  }

  func login(uid: String, authKey: String) async throws -> User {
    if let error = loginError { throw error }
    return loginUser ?? User(uid: uid, name: "Test User")
  }

  func logout() async throws {}
  func getLoggedInUser() -> User? { loginUser }
  func sendMessage(_ message: TextMessage) async throws -> TextMessage { message }
}

3. XCTest patterns

Async/await tests

import XCTest
@testable import YourApp

final class ChatViewControllerTests: XCTestCase {
  func testInitializeRunsBeforeLogin() async throws {
    let mock = CometChatServiceMock()
    let vc = ChatViewController(service: mock)

    await vc.bootstrapCometChat()

    XCTAssertEqual(mock.initializeCallCount, 1)
    XCTAssertNotNil(vc.currentUser)
  }

  func testLoginFailureSurfacesError() async throws {
    let mock = CometChatServiceMock()
    mock.loginError = NSError(domain: "Test", code: 401, userInfo: [NSLocalizedDescriptionKey: "Unauthorized"])

    let vc = ChatViewController(service: mock)
    await vc.bootstrapCometChat()

    XCTAssertEqual(vc.errorMessage, "Unauthorized")
    XCTAssertEqual(vc.errorLabel?.textColor, .red)            // skill rule: error UI must be visible
  }
}

Expectation-based tests (legacy / non-async code)

func testMessageSendFiresCallback() {
  let expectation = expectation(description: "message sent")

  let mock = CometChatServiceMock()
  let vc = ChatViewController(service: mock)
  vc.send(message: "Hello") { _ in
    expectation.fulfill()
  }

  wait(for: [expectation], timeout: 1.0)
}

For SDK callback-based code, prefer wrapping in protocol + async/await per Section 2; this pattern is for legacy code only.

4. SwiftUI view tests

import SwiftUI
import XCTest
@testable import YourApp

@MainActor
final class ProfileViewTests: XCTestCase {
  func testCallButtonInvokesService() throws {
    let mock = CallServiceMock()
    let view = ProfileView(user: testUser(), callService: mock)

    let host = UIHostingController(rootView: view)
    host.loadViewIfNeeded()

    // Hard to interact with SwiftUI views from XCTest directly — use ViewInspector or UI tests
    // For most behavioral tests, prefer XCUITest (Section 6)
  }
}

Pure SwiftUI testing is hard; pragmatic choice is to keep most tests at the service / view-model layer and put view assertions in UI tests.

ViewInspector (third-party)

For SwiftUI views you do want to inspect from XCTest, install ViewInspector:

import ViewInspector

func testProfileShowsUserName() throws {
  let user = testUser()
  let view = ProfileView(user: user)
  let text = try view.inspect().find(text: user.name)
  XCTAssertNotNil(text)
}

Adds a runtime dep. Not strictly necessary if you have UI tests.

5. Snapshot testing

# Package.swift dependency
.package(url: "https://github.com/pointfreeco/swift-snapshot-testing.git", from: "1.15.0")

import SnapshotTesting
import XCTest
@testable import YourApp

final class ChatViewSnapshotTests: XCTestCase {
  func testEmptyChatView() {
    let view = ChatView(messages: [])
    let host = UIHostingController(rootView: view)
    assertSnapshot(matching: host, as: .image(on: .iPhone13))
  }

  func testChatViewWithMessages() {
    let messages = [
      TextMessage(receiverUid: "alice", text: "Hi", receiverType: .user),
      TextMessage(receiverUid: "bob", text: "Hey", receiverType: .user),
    ]
    let view = ChatView(messages: messages)
    let host = UIHostingController(rootView: view)
    assertSnapshot(matching: host, as: .image(on: .iPhone13))
  }
}

First run creates the reference image; subsequent runs diff against it. Commit the __Snapshots__ directory.

Gotcha: snapshot tests are sensitive to font rendering — if CI uses a different macOS version than dev, snapshots won't match. Pin runners to a known version.

6. UI tests (XCUITest)

import XCTest

final class ChatUITests: XCTestCase {
  override func setUp() {
    continueAfterFailure = false
    let app = XCUIApplication()
    app.launchEnvironment["UI_TEST_MODE"] = "1"
    app.launchEnvironment["TEST_UID"] = "cometchat-uid-1"
    app.launch()
  }

  func testLoginAndSeeConversations() {
    let app = XCUIApplication()
    XCTAssertTrue(app.staticTexts["Welcome"].waitForExistence(timeout: 10))
    app.buttons["Messages"].tap()
    XCTAssertTrue(app.staticTexts["Conversations"].waitForExistence(timeout: 10))
  }

  func testSendMessage() {
    let app = XCUIApplication()
    app.buttons["Messages"].tap()
    app.buttons["cometchat-uid-2"].tap()

    let composer = app.textFields["Type a message"]
    composer.tap()
    composer.typeText("Hello from UI test")
    app.buttons["Send"].tap()

    XCTAssertTrue(app.staticTexts["Hello from UI test"].waitForExistence(timeout: 5))
  }
}

UI_TEST_MODE flag: in production code, check this env var and skip animations / use shorter timeouts:

if ProcessInfo.processInfo.environment["UI_TEST_MODE"] == "1" {
  UIView.setAnimationsEnabled(false)
}

Test users: UI tests need real login. Use the dev cometchat-uid-1 through cometchat-uid-5; never use production credentials.

7. CI configuration

GitHub Actions

name: tests
on: [push, pull_request]

jobs:
  unit:
    runs-on: macos-13                              # pin macOS version for snapshot stability
    steps:
      - uses: actions/checkout@v4
      - run: |
          xcodebuild test \
            -scheme YourApp \
            -destination "platform=iOS Simulator,name=iPhone 15,OS=17.0" \
            -only-testing:YourAppTests \
            COMETCHAT_TEST_APP_ID="${{ secrets.TEST_COMETCHAT_APP_ID }}" \
            COMETCHAT_TEST_REGION="${{ secrets.TEST_COMETCHAT_REGION }}" \
            COMETCHAT_TEST_AUTH_KEY="${{ secrets.TEST_COMETCHAT_AUTH_KEY }}"

  ui:
    runs-on: macos-13
    needs: unit
    steps:
      - uses: actions/checkout@v4
      - run: |
          xcodebuild test \
            -scheme YourApp \
            -destination "platform=iOS Simulator,name=iPhone 15,OS=17.0" \
            -only-testing:YourAppUITests \
            COMETCHAT_TEST_APP_ID="${{ secrets.TEST_COMETCHAT_APP_ID }}"

Xcode Cloud

Configure in App Store Connect → Xcode Cloud. Use the same env var convention; Xcode Cloud injects them into xcodebuild automatically.

8. Anti-patterns

1. Mocking CometChat directly (without the protocol wrapper). The static methods aren't swappable; you'd need OCMock and method swizzling. The protocol wrapper is cleaner.
2. Using real WebSocket connections in unit tests. They're flaky on CI. Mock the service layer.
3. Snapshot tests on a Mac with system font preference different from CI. Pin macOS + Xcode versions.
4. Hardcoding cometchat-uid-1 strings across many tests. Centralize via a TestUsers enum so renames are one-edit.
5. Skipping continueAfterFailure = false in UI tests. Default UI tests continue running after a failure, hiding root causes in cascade failures.
6. Storing test credentials in Secrets.swift. Use env vars passed via xcodebuild and read via ProcessInfo.processInfo.environment["..."] in test bundles only.

9. Verification checklist

• CometChatServiceProtocol (or similar) wrapping the SDK; production VCs use it via DI
• Mock implementation in Tests/Mocks/
• At least one test for "init resolves before VC is functional"
• At least one test for "error UI shows on init/login failure"
• Snapshot tests for at least the empty + populated states of chat surfaces
• At least one UI test for login + see conversations
• Test target uses dedicated CometChat test App ID via env vars (not Secrets.swift)
• CI pinned to macOS + Xcode versions
• No continueAfterFailure = true in UI tests

10. Pointers

• cometchat-ios-calls/references/callkit-and-pushkit.md — calls + CallKit testing
• cometchat-ios-core — init, login, Secrets patterns the tests assert against
• cometchat-ios-troubleshooting — when tests pass but production breaks