Dependency injection resolution of async factory - dependency-injection

Question

Having some issues with injecting a database connection into a class via the di.dart package. Specifically, resolving an async dependency in the toFactory option.
Both attempts result in the
NoSuchMethodError: Class '_Future' has no instance method 'query'.
error and it's unclear the correct path forward. I would prefer to keep the conn property without being wrapped in a Future. I've attempted doing the unwrapping of the Future in the class constructor but async constructors are not allowed in Dart at this time.
import 'package:postgresql/pool.dart';
import 'package:postgresql/postgresql.dart';
import 'package:di/di.dart';
main() async {
var uri = "postgres://username:password#localhost:5432/database";
var pool = new Pool(uri, minConnections: 2, maxConnections: 5);
await pool.start();
Module module = new Module();
module.bind(TestQuery);
module.bind(TestController);
module.bind(Pool, toValue: pool);
module.bind(Connection, toFactory: (pool) => pool.connect(), inject: [Pool]);
var injector = new ModuleInjector([module]);
var html = await injector.get(TestController).index();
print(html);
}
class BaseQuery {
Connection conn;
BaseQuery(Connection this.conn);
}
class TestQuery extends BaseQuery {
TestQuery(Connection conn) : super(conn); // type '_Future' is not a subtype of type 'Connection' of 'conn' where
run() async {
var results = await conn.query("select 1").toList();
// Do some data manipulation
return results;
}
}
class TestController {
TestQuery testQuery;
TestController(TestQuery this.testQuery);
index() async {
var results = await testQuery.run();
var html = "<pre>" + results.toString() + "</pre>";
return html;
}
}

Answer 1

I can reproduce but when I change the line to
var conn = await injector.get(Connection);
var res = await conn.query("select 1").toList();
it working fine.
I think your code should work as well though.