feat: enable background mode for the example app

Bucketeer.xcodeproj/xcshareddata/xcschemes/ExampleSwiftUI.xcscheme

@@ -0,0 +1,78 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "1420"
+   version = "1.3">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "947A04ED2A9CF08500BE33F7"
+               BuildableName = "ExampleSwiftUI.app"
+               BlueprintName = "ExampleSwiftUI"
+               ReferencedContainer = "container:Bucketeer.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES">
+      <Testables>
+      </Testables>
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      launchStyle = "0"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "947A04ED2A9CF08500BE33F7"
+            BuildableName = "ExampleSwiftUI.app"
+            BlueprintName = "ExampleSwiftUI"
+            ReferencedContainer = "container:Bucketeer.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "947A04ED2A9CF08500BE33F7"
+            BuildableName = "ExampleSwiftUI.app"
+            BlueprintName = "ExampleSwiftUI"
+            ReferencedContainer = "container:Bucketeer.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>

Bucketeer/Sources/Internal/Event/EventInteractor.swift

@@ -27,19 +27,9 @@ final class EventInteractorImpl: EventInteractor {
     let logger: Logger?
     let featureTag: String
 
-    private let sendEventSemaphore = DispatchSemaphore(value: 1)
     private let metadata: [String: String]
     private var eventUpdateListener: EventUpdateListener?
 
-    deinit {
-        // If EventInteractor deinit before the sendEvents() finished could cause "bad instrucstion crash"
-        // Because APIClient didn't provides the way to cancel the ongoing request
-        // over-signaling does not introduce new problems
-        // https://stackoverflow.com/questions/70457141/safe-to-signal-semaphore-before-deinitialization-just-in-case
-        // verified it will be okay see `testSemaphoreOverSignalShouldNotCauseProblem` in EventInteractorTests.swift
-        sendEventSemaphore.signal()
-    }
-
     init(
         sdkVersion: String,
         appVersion: String,

Bucketeer/Sources/Internal/Scheduler/BackgroundTask.swift

@@ -0,0 +1,10 @@
+import Foundation
+#if canImport(BackgroundTasks)
+import BackgroundTasks
+
+@available(iOS 13.0, tvOS 13.0, *)
+protocol BackgroundTask: ScheduledTask {
+    func getTaskIndentifier() -> String
+    func handle(_ task: BGTask)
+}
+#endif

Bucketeer/Sources/Internal/Scheduler/BackgroundTaskIndentifier.swift

@@ -0,0 +1,6 @@
+import Foundation
+
+class BackgroundTaskIndentifier {
+    static let fetchEvaluations = "io.bucketeer.background.fetch.evaluations"
+    static let flushEvents = "io.bucketeer.background.flush.events"
+}

Bucketeer/Sources/Internal/Scheduler/EvaluationBackgroundTask.swift

@@ -5,8 +5,6 @@ import BackgroundTasks
 
 @available(iOS 13.0, tvOS 13.0, *)
 final class EvaluationBackgroundTask {
-    static let taskId = "io.bucketeer.background.fetch.evaluations"
-
     private weak var component: Component?
     private let queue: DispatchQueue
 
@@ -15,40 +13,49 @@ final class EvaluationBackgroundTask {
         self.queue = queue
     }
 
-    func register() {
-        BGTaskScheduler.shared.register(forTaskWithIdentifier: Self.taskId, using: nil) { task in
-            self.handleAppRefresh(task: task as? BGAppRefreshTask)
-        }
-    }
-
     func scheduleAppRefresh() {
-        let request = BGAppRefreshTaskRequest(identifier: Self.taskId)
+        let request = BGProcessingTaskRequest(identifier: getTaskIndentifier())
+        request.requiresNetworkConnectivity = true
         let interval: TimeInterval = TimeInterval(component?.config.backgroundPollingInterval ?? Constant.DEFAULT_BACKGROUND_POLLING_INTERVAL_MILLIS)
         request.earliestBeginDate = Date(timeIntervalSinceNow: interval / 1000)
 
         do {
             try BGTaskScheduler.shared.submit(request)
+            component?.config.logger?.debug(message: "[EvaluationBackgroundTask] The background task is scheduled.")
         } catch {
             component?.config.logger?.error(error)
         }
     }
 
-    func handleAppRefresh(task: BGAppRefreshTask?) {
+    private func handleAppRefresh(_ task: BGTask) {
+        component?.config.logger?.debug(message: "[EvaluationBackgroundTask] handleAppRefresh")
         // Schedule a new refresh task.
         scheduleAppRefresh()
 
         guard let component = self.component else { return }
-        BKTClient.fetchEvaluationsSync(
-            component: component,
-            dispatchQueue: queue,
-            timeoutMillis: nil,
-            completion: { error in
-                task?.setTaskCompleted(success: error == nil)
+        queue.async { [weak self] in
+            if let taskQueue = self?.queue {
+                BKTClient.fetchEvaluationsSync(
+                    component: component,
+                    dispatchQueue: taskQueue,
+                    timeoutMillis: nil,
+                    completion: { error in
+                        task.setTaskCompleted(success: error == nil)
+                        if let error {
+                            self?.component?.config.logger?.error(error)
+                        } else {
+                            self?.component?.config.logger?.debug(message: "[EventBackgroundTask] success")
+                        }
+                    }
+                )
             }
-        )
+        }
         // Provide the background task with an expiration handler that cancels the operation.
-        task?.expirationHandler = { [weak self] in
-            self?.component?.config.logger?.warn(message: "The background task is expired.")
+        task.expirationHandler = { [weak self] in
+            self?.component?.config.logger?.debug(message: "[EvaluationBackgroundTask] The background task is expired.")
+            // Must set task completed, if we don't do this OS will throttle and limit our background task request
+            // https://developer.apple.com/videos/play/wwdc2022/10142/
+            task.setTaskCompleted(success: false)
         }
     }
 }
@@ -60,8 +67,18 @@ extension EvaluationBackgroundTask: ScheduledTask {
     }
 
     func stop() {
-        BGTaskScheduler.shared.cancel(taskRequestWithIdentifier: Self.taskId)
+        BGTaskScheduler.shared.cancel(taskRequestWithIdentifier: getTaskIndentifier())
     }
 }
 
+@available(iOS 13.0, tvOS 13.0, *)
+extension EvaluationBackgroundTask: BackgroundTask {
+    func getTaskIndentifier() -> String {
+        return BackgroundTaskIndentifier.fetchEvaluations
+    }
+
+    func handle(_ task: BGTask) {
+        handleAppRefresh(task)
+    }
+}
 #endif

Bucketeer/Sources/Internal/Scheduler/EventBackgroundTask.swift

@@ -5,8 +5,6 @@ import BackgroundTasks
 
 @available(iOS 13.0, tvOS 13.0, *)
 final class EventBackgroundTask {
-    static let taskId = "io.bucketeer.background.flush.events"
-
     private weak var component: Component?
     private let queue: DispatchQueue
 
@@ -15,40 +13,42 @@ final class EventBackgroundTask {
         self.queue = queue
     }
 
-    func register() {
-        BGTaskScheduler.shared.register(forTaskWithIdentifier: Self.taskId, using: nil) { task in
-            self.handleAppRefresh(task: task as? BGAppRefreshTask)
-        }
-    }
-
     func scheduleAppRefresh() {
-        let request = BGAppRefreshTaskRequest(identifier: Self.taskId)
+        let request = BGProcessingTaskRequest(identifier: getTaskIndentifier())
+        request.requiresNetworkConnectivity = true
         let interval: TimeInterval = TimeInterval(component?.config.eventsFlushInterval ?? Constant.DEFAULT_FLUSH_INTERVAL_MILLIS)
         request.earliestBeginDate = Date(timeIntervalSinceNow: interval / 1000)
 
         do {
             try BGTaskScheduler.shared.submit(request)
+            component?.config.logger?.debug(message: "[EventBackgroundTask] The background task is scheduled.")
         } catch {
             component?.config.logger?.error(error)
         }
     }
 
-    func handleAppRefresh(task: BGAppRefreshTask?) {
+    private func handleAppRefresh(_ task: BGTask) {
+        component?.config.logger?.debug(message: "[EventBackgroundTask] handleAppRefresh")
         // Schedule a new refresh task.
         scheduleAppRefresh()
 
         guard let component = self.component else { return }
         queue.async {
             BKTClient.flushSync(component: component) { [weak self] error in
-                task?.setTaskCompleted(success: error == nil)
+                task.setTaskCompleted(success: error == nil)
                 if let error {
                     self?.component?.config.logger?.error(error)
+                } else {
+                    self?.component?.config.logger?.debug(message: "[EventBackgroundTask] success")
                 }
             }
         }
         // Provide the background task with an expiration handler that cancels the operation.
-        task?.expirationHandler = { [weak self] in
-            self?.component?.config.logger?.warn(message: "The background task is expired.")
+        task.expirationHandler = { [weak self] in
+            self?.component?.config.logger?.debug(message: "[EventBackgroundTask] The background task is expired.")
+            // Must set task completed, if we don't do this OS will throttle and limit our background task request
+            // https://developer.apple.com/videos/play/wwdc2022/10142/
+            task.setTaskCompleted(success: false)
         }
     }
 }
@@ -60,8 +60,18 @@ extension EventBackgroundTask: ScheduledTask {
     }
 
     func stop() {
-        BGTaskScheduler.shared.cancel(taskRequestWithIdentifier: Self.taskId)
+        BGTaskScheduler.shared.cancel(taskRequestWithIdentifier: getTaskIndentifier())
     }
 }
 
+@available(iOS 13.0, tvOS 13.0, *)
+extension EventBackgroundTask: BackgroundTask {
+    func getTaskIndentifier() -> String {
+        return BackgroundTaskIndentifier.flushEvents
+    }
+
+    func handle(_ task: BGTask) {
+        handleAppRefresh(task)
+    }
+}
 #endif