Copy powersync_db_worker to powersync_core for tests

Author: mugikhan

packages/powersync_core/test/server/worker_server.dart

@@ -24,7 +24,7 @@ Future<void> hybridMain(StreamChannel<Object?> channel) async {
 
   if (!(await File(workerOutputPath).exists())) {
     throw AssertionError(
-        'powersync_db.worker.js file should be present in the powersync/assets folder');
+        'powersync_db.worker.js file should be present in the powersync_core/assets folder');
   }
 
   final server = await HttpServer.bind('localhost', 0);

scripts/compile_webworker.dart

@@ -32,6 +32,13 @@ Future<void> main() async {
     throw Exception('Could not compile worker: ${process.stdout.toString()}');
   }
 
+  final workerFile = File(outputPath);
+
+  //Copy worker to powersync_core
+  final powersyncCoreAssetsPath =
+      path.join(repoRoot, 'packages/powersync_core/assets/$workerFilename');
+  workerFile.copySync(powersyncCoreAssetsPath);
+
   // Copy this to all demo apps web folders
   final demosRoot = path.join(repoRoot, 'demos');
   final demoDirectories =
@@ -44,6 +51,6 @@ Future<void> main() async {
       continue;
     }
     final demoOutputPath = path.join(demoWebDir, workerFilename);
-    File(outputPath).copySync(demoOutputPath);
+    workerFile.copySync(demoOutputPath);
   }
 }