Handle task cancellation in MastodonController.run

Tusker/API/MastodonController.swift

@@ -68,7 +68,7 @@ class MastodonController: ObservableObject {
     }
     
     func run<Result>(_ request: Request<Result>) async throws -> (Result, Pagination?) {
-        return try await withCheckedThrowingContinuation({ continuation in
+        let result: (Result, Pagination?) = try await withCheckedThrowingContinuation({ continuation in
             client.run(request) { response in
                 switch response {
                 case .failure(let error):
@@ -78,6 +78,8 @@ class MastodonController: ObservableObject {
                 }
             }
         })
+        try Task.checkCancellation()
+        return result
     }
     
     /// - Returns: A tuple of client ID and client secret.

Tusker/Screens/Compose/ComposeAttachmentsList.swift

@@ -234,7 +234,6 @@ struct SheetOrPopover<V: View>: ViewModifier {
     @Environment(\.horizontalSizeClass) var sizeClass
     
     func body(content: Content) -> some View {
-        let _ = print("isPresented: \(isPresented)")
         if sizeClass == .compact {
             content.sheet(isPresented: $isPresented, content: view)
         } else {

Tusker/Screens/Profile/ProfileStatusesViewController.swift

@@ -12,8 +12,8 @@ import Combine
 
 class ProfileStatusesViewController: UIViewController, TimelineLikeCollectionViewController {
     
-    unowned var owner: ProfileViewController
+    weak var owner: ProfileViewController?
-    var mastodonController: MastodonController { owner.mastodonController }
+    let mastodonController: MastodonController
     private(set) var accountID: String!
     let kind: Kind
     var initialHeaderMode: HeaderMode?
@@ -37,6 +37,7 @@ class ProfileStatusesViewController: UIViewController, TimelineLikeCollectionVie
         self.accountID = accountID
         self.kind = kind
         self.owner = owner
+        self.mastodonController = owner.mastodonController
         
         super.init(nibName: nil, bundle: nil)
         
@@ -130,7 +131,7 @@ class ProfileStatusesViewController: UIViewController, TimelineLikeCollectionVie
                         let view = ProfileHeaderView.create()
                         view.delegate = self.profileHeaderDelegate
                         view.updateUI(for: id)
-                        view.pagesSegmentedControl.selectedSegmentIndex = self.owner.currentIndex ?? 0
+                        view.pagesSegmentedControl.selectedSegmentIndex = self.owner?.currentIndex ?? 0
                         cell.addHeader(view)
                     case .placeholder(height: let height):
                         _ = cell.addConstraint(height: height)

Tusker/Screens/Utilities/Previewing.swift

@@ -60,9 +60,9 @@ extension MenuActionProvider {
                 draft.visibility = .direct
                 self.navigationDelegate?.compose(editing: draft)
             }),
-            UIDeferredMenuElement.uncached({ @MainActor elementHandler in
+            UIDeferredMenuElement.uncached({ @MainActor [unowned self] elementHandler in
                 let relationship = Task {
-                    await self.fetchRelationship(accountID: accountID, mastodonController: mastodonController)
+                    await fetchRelationship(accountID: accountID, mastodonController: mastodonController)
                 }
                 // workaround for #198, may result in showing outdated relationship, so only do so where necessary
                 if ProcessInfo.processInfo.isiOSAppOnMac,
@@ -392,19 +392,6 @@ extension MenuActionProvider {
         })
     }
     
-    private func fetchRelationship(accountID: String, mastodonController: MastodonController) async -> RelationshipMO? {
-        let req = Client.getRelationships(accounts: [accountID])
-        guard let (relationships, _) = try? await mastodonController.run(req),
-              let r = relationships.first else {
-            return nil
-        }
-        return await withCheckedContinuation { continuation in
-            mastodonController.persistentContainer.addOrUpdate(relationship: r, in: mastodonController.persistentContainer.viewContext) { mo in
-                continuation.resume(returning: mo)
-            }
-        }
-    }
-    
     @MainActor
     private func followAction(for relationship: RelationshipMO, mastodonController: MastodonController) -> UIMenuElement? {
         guard let ownAccount = mastodonController.account,
@@ -433,6 +420,19 @@ extension MenuActionProvider {
     
 }
 
+private func fetchRelationship(accountID: String, mastodonController: MastodonController) async -> RelationshipMO? {
+    let req = Client.getRelationships(accounts: [accountID])
+    guard let (relationships, _) = try? await mastodonController.run(req),
+          let r = relationships.first else {
+        return nil
+    }
+    return await withCheckedContinuation { continuation in
+        mastodonController.persistentContainer.addOrUpdate(relationship: r, in: mastodonController.persistentContainer.viewContext) { mo in
+            continuation.resume(returning: mo)
+        }
+    }
+}
+
 struct MenuPreviewHelper {
     static func willPerformPreviewAction(animator: UIContextMenuInteractionCommitAnimating, presenter: UIViewController) {
         if let viewController = animator.previewViewController {

Tusker/TimelineLikeController.swift

@@ -65,6 +65,8 @@ actor TimelineLikeController<Item> {
             await loadingIndicator.end()
             await emit(event: .replaceAllItems(items, token))
             state = .idle
+        } catch is CancellationError {
+            return
         } catch {
             await loadingIndicator.end()
             await emit(event: .loadAllError(error, token))
@@ -85,6 +87,8 @@ actor TimelineLikeController<Item> {
             }
             await emit(event: .prependItems(items, token))
             state = .idle
+        } catch is CancellationError {
+            return
         } catch {
             await emit(event: .loadNewerError(error, token))
             state = .idle
@@ -113,6 +117,8 @@ actor TimelineLikeController<Item> {
             await loadingIndicator.end()
             await emit(event: .appendItems(items, token))
             state = .idle
+        } catch is CancellationError {
+            return
         } catch {
             await loadingIndicator.end()
             await emit(event: .loadOlderError(error, token))

Tusker/Views/Profile Header/ProfileHeaderView.swift

@@ -119,12 +119,12 @@ class ProfileHeaderView: UIView {
             
             let request = Client.getRelationships(accounts: [accountID])
             mastodonController.run(request) { [weak self] (response) in
-                guard let self = self,
+                guard let mastodonController = self?.mastodonController,
                       case let .success(results, _) = response,
                       let relationship = results.first else {
                     return
                 }
-                self.mastodonController.persistentContainer.addOrUpdate(relationship: relationship)
+                mastodonController.persistentContainer.addOrUpdate(relationship: relationship)
             }
         }