uc-compass-bot

@UIApplicationMain 
final class AppDelegate: UIResponder, UIApplicationDelegate {
    func applicationDidReceiveMemoryWarning(_ application: UIApplication) {
        var properties: [String: String] = [:]

        if let footprint = memoryFootprint {
            properties["memory"] = String(format: "%d MB", footprint / 1024 / 1024)
        }

        // Trigger "Analytics Event" or "Non-Fatal Crash" or persist locally and send to server later

uc-compass-bot

class ViewController: UIViewController {
  deinit {
    print("View Controller has been released") // Set breakpoint on this line
  }
}

uc-compass-bot

import Foundation

public class MemoryChecker {
    public static func verifyDealloc(object: AnyObject?) {
        #if DEBUG
            DispatchQueue.main.asyncAfter(deadline: .now() + 5) { [weak object] in
                if let object = object {
                    fatalError("Class Not Deallocated: \(String(describing: object.classForCoder ?? object)))")
                }
            }

uc-compass-bot

import UIKit

class NavigationController: UINavigationController {
    override func popViewController(animated: Bool) -> UIViewController? {
        let viewController = super.popViewController(animated: animated)
        MemoryChecker.verifyDealloc(object: viewController)
        return viewController
    }
}

uc-compass-bot

import UIKit

class NavigationController: UINavigationController {
    deinit {
        viewControllers.forEach { MemoryChecker.verifyDealloc(object: $0) }
    }
}

uc-compass-bot

import UIKit

class TableView: UITableView {
    private var allCells: [WeakBox<UITableViewCell>] = []

    private func appendIfNotPresent(_ cell: UITableViewCell) {
        if allCells.first(where: { $0.unbox === cell }) == nil {
            allCells.append(WeakBox(cell))
        }
    }

uc-compass-bot

import UIKit

class CollectionView: UICollectionView {
    private var allCells: [WeakBox<UICollectionViewCell>] = []

    private func appendIfNotPresent(_ cell: UICollectionViewCell) {
        if allCells.first(where: { $0.unbox === cell }) == nil {
            allCells.append(WeakBox(cell))
        }
    }

uc-compass-bot

import Foundation

class WeakBox<A: AnyObject> {
    weak var unbox: A?

    init(_ value: A) {
        unbox = value
    }
}

uc-compass-bot

class ParentViewController: UIViewController, ChildViewControllerProtocol {
    let childViewController = ChildViewController()
    
    func prepareChildViewController() {
        childViewController.delegate = self  // ❌ Strong reference, retain cycle
    }
}
 
protocol ChildViewControllerProtocol: class {}
 

uc-compass-bot

weak var delegate: ChildViewControllerProtocol?  // ✅ No retain cycle