review-case

name	review-case
description	Structured code review for a case in the APIExample (UIKit + Swift) project. Checks engine lifecycle, thread safety, permissions, error handling, API correctness, and code conventions.
compatibility	["Cursor","Kiro","Windsurf","Claude","Copilot"]
license	MIT
metadata	{"author":"APIExample Team","version":"1.0.0","platform":"iOS"}

review-case — APIExample

Review Dimensions (in priority order)

1. Engine Lifecycle

The most critical dimension. Leaks here cause crashes in subsequent examples.

Check:

• AgoraRtcEngineKit.sharedEngine(with:delegate:) called in viewDidLoad (not in Entry VC)
• leaveChannel() + AgoraRtcEngineKit.destroy() called in willMove(toParent:) when parent == nil
• No engine instance stored beyond the Main VC's lifetime

Correct:

override func willMove(toParent parent: UIViewController?) {
    super.willMove(toParent: parent)
    if parent == nil {
        agoraKit?.leaveChannel()
        AgoraRtcEngineKit.destroy()
    }
}

Wrong:

// Missing destroy — engine leaks
override func viewDidDisappear(_ animated: Bool) {
    agoraKit?.leaveChannel()
}

---

2. Thread Safety

All AgoraRtcEngineDelegate callbacks may arrive on a background thread.

Check:

• Every UI update inside a delegate callback is wrapped in DispatchQueue.main.async { }
• No UIView, UILabel, or other UIKit objects mutated directly in callbacks

Correct:

func rtcEngine(_ engine: AgoraRtcEngineKit, didJoinedOfUid uid: UInt, elapsed: Int) {
    DispatchQueue.main.async {
        self.remoteView.isHidden = false
        self.setupRemoteVideo(uid: uid)
    }
}

Wrong:

func rtcEngine(_ engine: AgoraRtcEngineKit, didJoinedOfUid uid: UInt, elapsed: Int) {
    remoteView.isHidden = false  // UI update on background thread
}

---

3. Permissions

Check:

• Camera permission requested before joinChannel() for video cases
• Microphone permission requested before joinChannel() for all cases
• joinChannel() called only inside the permission grant callback, not before

Correct:

AgoraAudioSession.sharedInstance().requestRecordPermission { [weak self] granted in
    guard granted else { return }
    self?.agoraKit?.joinChannel(...)
}

---

4. Error Handling

Check:

• Return value of joinChannel() checked (non-zero = error)
• rtcEngine(_:didOccurError:) delegate method implemented and logged
• Token expiry handled via rtcEngine(_:tokenPrivilegeWillExpire:) if token is used

---

5. Code Conventions

Check:

• Entry class inherits UIViewController, Main class inherits BaseViewController
• Entry class usually follows <ExampleName>Entry; the main controller may be <ExampleName>Main or an existing project-specific *ViewController name as long as storyboard wiring is correct
• configs dictionary used to pass data from Entry to Main (no direct property injection)
• File placed under Examples/Basic/ or Examples/Advanced/ matching the MenuItem section
• Storyboard ID of Main scene matches the controller field in MenuItem

---

6. API Usage Correctness

Check:

• setVideoEncoderConfiguration called before joinChannel, not after
• setupLocalVideo called before startPreview and joinChannel
• enableVideo() called before setupLocalVideo for video cases
• setClientRole called before joinChannel for live streaming cases
• No deprecated API variants used (check SDK release notes if unsure)

---

7. Resource Cleanup

Check:

• Audio files / custom audio tracks stopped and released on exit
• External video sources unregistered (setExternalVideoSource(false, ...))
• Media player destroyed if created (agoraKit.destroy(mediaPlayer))
• Screen capture stopped if started (stopScreenCapture())
• Multi-camera capture stopped if started (stopCameraCapture(.cameraSecondary))

---

Review Output Format

For each issue found, report:

[SEVERITY] file/line — issue description
Suggestion: how to fix

Severity levels:

• [CRITICAL] — will cause crash, leak, or incorrect behavior
• [WARNING] — violates convention or may cause subtle bugs
• [INFO] — style or minor improvement suggestion

---

iOS-Specific Checks

• Background audio: if the case uses audio, verify AVAudioSession category is set appropriately and UIBackgroundModes includes audio if background playback is needed
• willMove(toParent:) is the correct hook — do NOT use viewWillDisappear or deinit for engine cleanup in navigation-based flows
• [weak self] must be used in all closures that capture self to avoid retain cycles with the engine delegate