injectStream<T> method

Future<void> injectStream<T>(String name, Stream<T> stream)

Injects stream on JS globalThis as an async iterable.

JavaScript consumes the values with for await (const value of name). Each pull requests the next Dart event, preserving backpressure. Stream errors reject the pending JS iteration and completion ends the iterator. The injected iterable remains available until the runtime is rebuilt or disposed; this method intentionally does not create a separate handle.

Implementation

Future<void> injectStream<T>(String name, Stream<T> stream) async {
  final terminalError = _terminalError;
  if (terminalError != null) {
    return Future<void>.error(terminalError);
  }
  final validName = _validateGlobalName(name);
  final callbackId = _nextCallbackId++;
  final callbackName = '__jsInjectedStream_$callbackId';
  await _bindRuntimeCallback(callbackId, callbackName, (_) async => stream);
  try {
    await evalRaw('''
(async () => {
globalThis[${jsonEncode(validName)}] = await globalThis[${jsonEncode(callbackName)}]();
})()
''', name: '<injectStream:$validName>');
  } finally {
    await _unbindRuntimeCallback(callbackId);
  }
}