Move AsyncOperation into Operations static library and add separate tests

1 files changed, 75 insertions, 0 deletions

diff --git a/ios/Operations/PresentAlertOperation.swift b/ios/Operations/PresentAlertOperation.swift
new file mode 100644
index 0000000000..f9fae07e0c
--- /dev/null
+++ b/ios/Operations/PresentAlertOperation.swift
@@ -0,0 +1,75 @@
+//
+//  PresentAlertOperation.swift
+//  PresentAlertOperation
+//
+//  Created by pronebird on 06/09/2021.
+//  Copyright © 2021 Mullvad VPN AB. All rights reserved.
+//
+
+#if canImport(UIKit)
+
+import UIKit
+
+public final class PresentAlertOperation: AsyncOperation {
+    private let alertController: UIAlertController
+    private let presentingController: UIViewController
+    private let presentCompletion: (() -> Void)?
+
+    public init(
+        alertController: UIAlertController,
+        presentingController: UIViewController,
+        presentCompletion: (() -> Void)? = nil
+    ) {
+        self.alertController = alertController
+        self.presentingController = presentingController
+        self.presentCompletion = presentCompletion
+
+        super.init(dispatchQueue: .main)
+    }
+
+    override public func operationDidCancel() {
+        // Guard against trying to dismiss the alert when operation hasn't started yet.
+        guard isExecuting else { return }
+
+        // Guard against dismissing controller during transition.
+        if !alertController.isBeingPresented, !alertController.isBeingDismissed {
+            dismissAndFinish()
+        }
+    }
+
+    override public func main() {
+        NotificationCenter.default.addObserver(
+            self,
+            selector: #selector(alertControllerDidDismiss(_:)),
+            name: AlertPresenter.alertControllerDidDismissNotification,
+            object: alertController
+        )
+
+        presentingController.present(alertController, animated: true) {
+            self.presentCompletion?()
+
+            // Alert operation was cancelled during transition?
+            if self.isCancelled {
+                self.dismissAndFinish()
+            }
+        }
+    }
+
+    private func dismissAndFinish() {
+        NotificationCenter.default.removeObserver(
+            self,
+            name: AlertPresenter.alertControllerDidDismissNotification,
+            object: alertController
+        )
+
+        alertController.dismiss(animated: false) {
+            self.finish()
+        }
+    }
+
+    @objc private func alertControllerDidDismiss(_ note: Notification) {
+        finish()
+    }
+}
+
+#endif