add async version of update() method + update examples

Author: jessesquires

Example/Sources/List/ListViewController.swift

@@ -19,6 +19,7 @@ final class ListViewController: ExampleViewController, CellEventCoordinator {
 
     lazy var driver = CollectionViewDriver(
         view: self.collectionView,
+        options: .init(diffOnBackgroundQueue: true),
         emptyViewProvider: sharedEmptyViewProvider,
         cellEventCoordinator: self
     )
@@ -27,9 +28,11 @@ final class ListViewController: ExampleViewController, CellEventCoordinator {
         didSet {
             // Every time the model updates, regenerate and set the view model
             let viewModel = self.makeViewModel()
-            self.driver.update(viewModel: viewModel, animated: true) {
-                print("list did update!")
-                print($0.viewModel)
+
+            Task { @MainActor in
+                await self.driver.update(viewModel: viewModel)
+                print("list did update! async")
+                print(viewModel)
             }
         }
     }

Sources/CollectionViewDriver.swift

@@ -147,6 +147,25 @@ public final class CollectionViewDriver: NSObject {
         )
     }
 
+    /// An async version of ``update(viewModel:animated:completion:)``.
+    ///
+    /// Updates the collection with the provided `viewModel`.
+    /// This method will trigger a diff between the previous view model and the newly provided view model.
+    ///
+    /// - Parameters:
+    ///   - viewModel: The new collection view model.
+    ///   - animated: Whether or not to animate updates.
+    ///
+    /// - Warning: If you provide a `viewModel` with an `id` different from the previous one,
+    /// this is considered a *replacement*. By default, the driver will animate the diff between the view models.
+    /// You can customize this behavior via the ``options`` for the driver.
+    public func update(viewModel new: CollectionViewModel, animated: Bool = true) async {
+        await withCheckedContinuation { continuation in
+            self.update(viewModel: new, animated: animated)
+            continuation.resume()
+        }
+    }
+
     // MARK: Private
 
     private func _registerAllViews(for viewModel: CollectionViewModel) {