quickjs_runtime

A pure-Dart QuickJS JavaScript runtime on dart:ffi with synchronous host callbacks. No Flutter, no Flutter SDK — dart pub get && dart test is all you need.

• Vendored QuickJS 2024-01-13 sources
• A C bridge (native/quickjs_bridge.c) with JSON-based marshaling: JS arguments are stringified to JSON in C, passed to a synchronous Dart callback (NativeCallable), and the JSON result is parsed back into a JS value
• One flat C ABI: qjs_create_runtime, qjs_eval, qjs_register_host_fn, …

Build

tool/build_quickjs.sh   # produces native/quickjs/libquickjs_bridge.so (gcc)

The library is looked up via the JSR_QUICKJS_LIB env var, inside this package's checkout, or in <cwd>/native/quickjs/ — in that order.

Usage

import 'package:quickjs_runtime/quickjs_runtime.dart';

final rt = QuickjsRuntime();
rt.registerHostFunction('add', (argsJson) {
  final args = jsonDecode(argsJson) as List;
  return jsonEncode(args[0] + args[1]);
});
print(rt.eval('add(2, 3)')); // 5
rt.executePendingJobs();     // drain promise reactions
rt.close();

VM-only (dart:ffi): never import from a web-reachable path.

Testing

tool/build_quickjs.sh
dart test