Return result from write method callback. Fixes #67

lib/src/realm_class.dart

@@ -166,11 +166,12 @@ class Realm {
   ///
   /// If no exception is thrown from within the callback, the transaction will be committed.
   /// It is more efficient to update several properties or even create multiple objects in a single write transaction.
-  void write(void Function() writeCallback) {
+  TResult write<TResult>(TResult Function() writeCallback) {
     try {
       realmCore.beginWrite(this);
-      writeCallback();
+      TResult result = writeCallback();
       realmCore.commitWrite(this);
+      return result;
     } catch (e) {
       if (_isInTransaction) {
         realmCore.rollbackWrite(this);
@@ -234,7 +235,7 @@ class Realm {
   }
 
   /// Deletes all [RealmObject]s of type `T` in the `Realm`
-  void deleteAll<T extends RealmObject>() => deleteMany(all<T>()); 
+  void deleteAll<T extends RealmObject>() => deleteMany(all<T>());
 }
 
 class Scheduler {
@@ -270,7 +271,7 @@ class Scheduler {
 extension RealmInternal on Realm {
   RealmHandle get handle => _handle;
   Scheduler get scheduler => _scheduler;
-  
+
   RealmObject createObject(Type type, RealmObjectHandle handle) {
     RealmMetadata metadata = _getMetadata(type);
 

test/realm_test.dart

@@ -153,6 +153,19 @@ Future<void> main([List<String>? args]) async {
     realm.close();
   });
 
+  test('Realm return added object', () {
+    var config = Configuration([Car.schema]);
+    var realm = Realm(config);
+    var car = Car('Mustang');
+
+    var returnedCar = realm.write(() {
+      return realm.add(car);
+    });
+    expect(returnedCar, car);
+
+    realm.close();
+  });
+
   test('Realm add multiple objects', () {
     final config = Configuration([Car.schema]);
     final realm = Realm(config);