Note Dart 2.15 is required for runIsolated.

Author: greenrobot-team

objectbox/CHANGELOG.md

@@ -2,9 +2,10 @@
 
 * Support [ObjectBox Admin](https://docs.objectbox.io/data-browser) for Android apps to browse 
   the database. #148
-* Add `Store.runIsolated` to run database operations (asynchronous) in the background. It spawns an
-  isolate, runs the given callback in that isolate with its own Store and returns the result of the
-  callback. This is similar to Flutters compute, but with the callback having access to a Store.
+* Add `Store.runIsolated` to run database operations (asynchronous) in the background 
+  (requires Flutter 2.8.0/Dart 2.15.0 or newer). It spawns an isolate, runs the given callback in that 
+  isolate with its own Store and returns the result of the callback. This is similar to Flutters 
+  compute, but with the callback having access to a Store. #384
 * Add `Store.attach` to attach to a Store opened in a directory. This is an improved replacement for 
   `Store.fromReference` to share a Store across isolates. It is no longer required to pass a
   Store reference and the underlying Store remains open until the last instance is closed. #376

objectbox/lib/src/native/store.dart

@@ -399,6 +399,9 @@ class Store {
   ///
   /// Instances of [callback] must be top-level functions or static methods
   /// of classes, not closures or instance methods of objects.
+  ///
+  /// Note: this requires Dart 2.15.0 or newer
+  /// (shipped with Flutter 2.8.0 or newer).
   Future<R> runIsolated<P, R>(
       TxMode mode, FutureOr<R> Function(Store, P) callback, P param) async {
     final resultPort = ReceivePort();

objectbox/test/basics_test.dart

@@ -4,6 +4,7 @@ import 'dart:io';
 import 'dart:isolate';
 
 import 'package:async/async.dart';
+import 'package:meta/meta.dart';
 import 'package:objectbox/internal.dart';
 import 'package:objectbox/src/native/bindings/bindings.dart';
 import 'package:objectbox/src/native/bindings/helpers.dart';
@@ -200,7 +201,21 @@ void main() {
     final futureResult =
         env.store.runIsolated(TxMode.write, readStringAndRemove, id);
     print('Count in main isolate: ${env.box.count()}');
-    final x = await futureResult;
+    final String x;
+    try {
+      x = await futureResult;
+    } catch (e) {
+      final dartVersion = RegExp('([0-9]+).([0-9]+).([0-9]+)')
+          .firstMatch(Platform.version)
+          ?.group(0);
+      if (dartVersion != null && dartVersion.compareTo('2.15.0') < 0) {
+        print('runIsolated requires Dart 2.15, ignoring error.');
+        env.closeAndDelete();
+        return;
+      } else {
+        rethrow;
+      }
+    }
     expect(x, 'foo!');
     expect(env.box.count(), 0); // Must be removed once awaited
     env.closeAndDelete();