Prevent the app from being suspended while refreshing a token (#193)

Sources/AuthFoundation/OAuth2/OAuth2Client.swift

@@ -200,8 +200,13 @@ public final class OAuth2Client {
                                                    refreshToken: refreshToken,
                                                    id: token.id,
                                                    configuration: clientSettings)
+                let backgroundTask = BackgroundTask(named: "Refresh Token \(token.id)")
                 request.send(to: self) { result in
                     self.refreshQueue.sync(flags: .barrier) {
+                        defer {
+                            backgroundTask.finish()
+                        }
+
                         switch result {
                         case .success(let response):
                             let newToken = response.result.token(merging: token)

Sources/AuthFoundation/Utilities/BackgroundTaskWrapper.swift

@@ -0,0 +1,39 @@
+//
+// Copyright (c) 2024-Present, Okta, Inc. and/or its affiliates. All rights reserved.
+// The Okta software accompanied by this notice is provided pursuant to the Apache License, Version 2.0 (the "License.")
+//
+// You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0.
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//
+// See the License for the specific language governing permissions and limitations under the License.
+//
+
+import Foundation
+
+#if os(iOS) || os(tvOS) || targetEnvironment(macCatalyst)
+import UIKit
+
+final class BackgroundTask {
+    let task: UIBackgroundTaskIdentifier
+
+    init(named name: String? = nil) {
+        task = UIApplication.shared.beginBackgroundTask(withName: name)
+    }
+
+    deinit {
+        finish()
+    }
+
+    func finish() {
+        UIApplication.shared.endBackgroundTask(task)
+    }
+}
+#else
+final class BackgroundTask {
+    init(named name: String? = nil) {}
+
+    func finish() {}
+}
+#endif

Tests/AuthFoundationTests/TokenTests.swift

@@ -125,8 +125,6 @@ final class TokenTests: XCTestCase {
 
 
     func testMFAAttestationTokenFailed() throws {
-        let request = MockTokenRequest(clientId: configuration.clientId,
-                                       url: configuration.baseURL)
         let decoder = defaultJSONDecoder
         decoder.userInfo = [
             .apiClientConfiguration: configuration,