[firebase_admob] Fix firebase_admob issues caused by un-handled exception situations

packages/firebase_admob/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.9.0+8
+
+* Handle exception in `BannerAd.dispose()` call for `no_ad_for_id` scenario.
+
 ## 0.9.0+7
 
 * Update Android gradle plugin, gradle, and Admob versions.

packages/firebase_admob/lib/firebase_admob.dart

@@ -238,7 +238,7 @@ abstract class MobileAd {
   /// Disposing a banner ad that's been shown removes it from the screen.
   /// Interstitial ads can't be programmatically removed from view.
   Future<bool> dispose() {
-    assert(_allAds[id] != null);
+    if (_allAds[id] == null) return Future<bool>.value(true);
     _allAds[id] = null;
     return _invokeBooleanMethod("disposeAd", <String, dynamic>{'id': id});
   }
@@ -520,9 +520,19 @@ class FirebaseAdMob {
 }
 
 Future<bool> _invokeBooleanMethod(String method, [dynamic arguments]) async {
-  final bool result = await FirebaseAdMob.instance._channel.invokeMethod<bool>(
-    method,
-    arguments,
-  );
+  bool result = false;
+  try {
+    result = await FirebaseAdMob.instance._channel.invokeMethod<bool>(
+      method,
+      arguments,
+    );
+  } on PlatformException catch (e) {
+    if (e.code == "no_ad_for_id") {
+      result = false;
+      return result;
+    }
+    rethrow;
+  }
+
   return result;
 }

packages/firebase_admob/pubspec.yaml

@@ -3,7 +3,7 @@ description: Flutter plugin for Firebase AdMob, supporting
   banner, interstitial (full-screen), and rewarded video ads
 author: Flutter Team <flutter-dev@googlegroups.com>
 homepage: https://github.com/FirebaseExtended/flutterfire/tree/master/packages/firebase_admob
-version: 0.9.0+7
+version: 0.9.0+8
 
 flutter:
   plugin:

packages/firebase_admob/test/firebase_admob_test.dart

@@ -18,6 +18,8 @@ void main() {
     final List<MethodCall> log = <MethodCall>[];
     final FirebaseAdMob admob = FirebaseAdMob.private(channel);
 
+    int invalidAdId;
+
     setUp(() async {
       channel.setMockMethodCallHandler((MethodCall methodCall) async {
         log.add(methodCall);
@@ -29,6 +31,15 @@ void main() {
           case 'showAd':
           case 'showRewardedVideoAd':
           case 'disposeAd':
+            if (methodCall.arguments != null) {
+              if (methodCall.arguments.containsKey('id') &&
+                  (invalidAdId != null)) {
+                if (invalidAdId == methodCall.arguments['id']) {
+                  invalidAdId = null;
+                  throw PlatformException(code: 'no_ad_for_id');
+                }
+              }
+            }
             return Future<bool>.value(true);
           default:
             assert(false);
@@ -138,5 +149,24 @@ void main() {
         isMethodCall('showRewardedVideoAd', arguments: null),
       ]);
     });
+
+    test('noAdForId', () async {
+      log.clear();
+
+      final BannerAd banner = BannerAd(
+        adUnitId: BannerAd.testAdUnitId,
+        size: AdSize.banner,
+      );
+      final int id = banner.id;
+      invalidAdId = banner.id;
+
+      expect(await banner.dispose(), false);
+
+      expect(log, <Matcher>[
+        isMethodCall('disposeAd', arguments: <String, dynamic>{
+          'id': id,
+        }),
+      ]);
+    });
   });
 }