dart:js_interop's dartify doesn't convert Promises to Futures on dart2wasm like dart2js/DDC. Instead it treats it like a JSValue:
import 'dart:js_interop';
import 'package:async_helper/async_helper.dart';
@JS('Promise.resolve')
external JSAny resolve(String s);
void main() {
asyncTest(() async {
await (resolve('').dartify() as Future<JSAny?>);
});
}results in:
Type 'JSValue' is not a subtype of type 'Future<JSValue?>' in type cast
but passes on dart2js/DDC.
The culprit is
|
Object? dartifyRaw(WasmExternRef? ref) { |
, where we never check for
Promises. DDC/dart2js does:
|
if (_isJavaScriptPromise(o)) { |
dart:js_interop'sdartifydoesn't convertPromises toFutures on dart2wasm like dart2js/DDC. Instead it treats it like aJSValue:results in:
but passes on dart2js/DDC.
The culprit is
sdk/sdk/lib/_internal/wasm/lib/js_helper.dart
Line 422 in 9329f7b
Promises. DDC/dart2js does:sdk/sdk/lib/_internal/js_shared/lib/js_util_patch.dart
Line 596 in 9329f7b