Redirection type of a redirecting factory can be deferred

tests/language/regress_23408_test.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:developer';
+library regress_23408_test;
+
 import 'package:expect/expect.dart';
 
-class Point {
-  int x, y;
-  Point(this.x, this.y);
+import 'regress_23408_lib.dart' deferred as lib;
+
+class C {
+  var v = 55;
+  C();
+  factory C.c() = lib.C;

[regis, 2015/06/30 18:16:31]

You should add a test where the redirection type is generic with a deferred type
argument, something like:

factory C.c() = List<lib.C>;

I suspect that the code is not yet able to handle that case correctly.

[hausner, 2015/06/30 21:51:00]

What is the behavior you expect? Using an unresolved type as a type parameter is
not a runtime error. The type argument is converted to dynamic in that case.

var x = new List<NoSuchType>();

The above creates a List<dynamic>.

var x = new List<UnloadedPrefix.C>();

This also creates a List<dynamic>.

Therefore, a factory forwarding to List<UnloadedPrefix.C> forwards to
List<dynamic>.

Discussing this with Gilad, we concluded that the Spec is not very clear on the
semantics of using a deferred type as a type argument. The intention is that the
type stays malformed and the argument is mapped to dynamic even after the
deferred type is loaded. 

Fortunately, this is what the VM implements :-) We don't allow deferred types in
type arguments and simply map them to dynamic.

I added a test case.

 }
 
 void main() {
-  var p_in = new Point(3, 4);
-  var p_out = inspect(p_in);
-  Expect.isTrue(identical(p_in, p_out));
+  Expect.throws(() => new C.c());
+  lib.loadLibrary().then((_) {
+    var z = new C.c();
+    Expect.equals(55, z.v);
+  });
 }