Addressing Firebase onBackgroundMessage bug - untested

firebase/flutterfire#9689 Made `channel` a regular field (non-static) and only set `backgroundChannel` (a static field) if it is null. This should keep the first `backgroundChannel` alive. Note that the `backgroundChannel` has to be static because it is called from the DownloadWorker, and it has no reference to the plugin.
781flyingdutchman · Jan 23, 2023 · 33c47a9 · 33c47a9
1 parent 4504ce8
commit 33c47a9
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Showing 2 changed files with 13 additions and 4 deletions.
diff --git a/android/src/main/kotlin/com/bbflight/background_downloader/BackgroundDownloaderPlugin.kt b/android/src/main/kotlin/com/bbflight/background_downloader/BackgroundDownloaderPlugin.kt
@@ -17,10 +17,11 @@ import kotlin.concurrent.write
 
 /** BackgroundDownloaderPlugin */
 class BackgroundDownloaderPlugin : FlutterPlugin, MethodCallHandler {
+    private var channel: MethodChannel? = null
+
     companion object {
         const val TAG = "BackgroundDownloaderPlugin"
         const val keyTasksMap = "com.bbflight.background_downloader.taskMap"
-        private var channel: MethodChannel? = null
         var backgroundChannel: MethodChannel? = null
         val prefsLock = ReentrantReadWriteLock()
         private lateinit var workManager: WorkManager
@@ -30,10 +31,15 @@ class BackgroundDownloaderPlugin : FlutterPlugin, MethodCallHandler {
     }
 
     override fun onAttachedToEngine(flutterPluginBinding: FlutterPlugin.FlutterPluginBinding) {
+        if (backgroundChannel == null) {
+            // only set background channel once, as it has to be static field
+            // and per https://github.com/firebase/flutterfire/issues/9689 other
+            // plugins can create multiple instances of the plugin
+            backgroundChannel = MethodChannel(flutterPluginBinding.binaryMessenger,
+                    "com.bbflight.background_downloader.background")
+        }
         channel = MethodChannel(flutterPluginBinding.binaryMessenger,
                 "com.bbflight.background_downloader")
-        backgroundChannel = MethodChannel(flutterPluginBinding.binaryMessenger,
-                "com.bbflight.background_downloader.background")
         channel?.setMethodCallHandler(this)
         workManager = WorkManager.getInstance(flutterPluginBinding.applicationContext)
         prefs = PreferenceManager.getDefaultSharedPreferences(
@@ -50,7 +56,6 @@ class BackgroundDownloaderPlugin : FlutterPlugin, MethodCallHandler {
     override fun onDetachedFromEngine(binding: FlutterPlugin.FlutterPluginBinding) {
         channel?.setMethodCallHandler(null)
         channel = null
-        backgroundChannel = null
     }
 
     override fun onMethodCall(call: MethodCall, result: Result) {

diff --git a/example/integration_test/downloader_integration_test.dart b/example/integration_test/downloader_integration_test.dart
@@ -59,6 +59,10 @@ void main() {
     } on FileSystemException {}
   });
 
+  tearDown(() async {
+    FileDownloader.destroy();
+  });
+
   group('Initialization', () {
     test('initialize', () {
       // confirm asserts work