promiseToFuture<T> function
Implementation
Future<T> promiseToFuture<T>(promise) {
var completer = new Completer<T>();
var then = convertDartClosureToJS((r) => completer.complete(r), 1);
var error = convertDartClosureToJS((e) => completer.completeError(e), 1);
JS('', '#.then(#, #)', promise, then, error);
return completer.future;
}