Add ClassSet to support ClassWorld.strictSubtypesOf

tests/compiler/dart2js/subtypeset_test.dart

Index: tests/compiler/dart2js/subtypeset_test.dart
diff --git a/tests/compiler/dart2js/subtypeset_test.dart b/tests/compiler/dart2js/subtypeset_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..66730410f0fdbc7606bebd82d521a2c6f2c4cdc7
--- /dev/null
+++ b/tests/compiler/dart2js/subtypeset_test.dart
@@ -0,0 +1,81 @@
+// 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.
+
+// Test for iterators on for [SubclassNode].
+
+library world_test;
+
+import 'package:expect/expect.dart';
+import 'package:async_helper/async_helper.dart';
+import 'type_test_helper.dart';
+import 'package:compiler/src/elements/elements.dart'
+       show Element, ClassElement;
+import 'package:compiler/src/universe/class_set.dart';
+import 'package:compiler/src/world.dart';
+
+void main() {
+  asyncTest(() => TypeEnvironment.create(r"""
+      ///        A
+      ///       / \
+      ///      B   C
+      ///     /   /|\
+      ///    D   E F G 
+      ///
+      class A {
+        call(H h, I i) {} // Make `H` and `I` part of the world.
+      }
+      class B extends A implements C {}
+      class C extends A {}
+      class D extends B implements A {}
+      class E extends C implements B {}
+      class F extends C {}
+      class G extends C {}
+      class H implements C {}
+      class I implements H {}
+      """,
+        mainSource: r"""
+      main() {
+        new A();
+        new C();
+        new D();
+        new E();
+        new F();
+        new G();
+      }
+      """,
+      useMockCompiler: false).then((env) {
+    World world = env.compiler.world;
+
+    ClassElement A = env.getElement("A");
+    ClassElement B = env.getElement("B");
+    ClassElement C = env.getElement("C");
+    ClassElement D = env.getElement("D");
+    ClassElement E = env.getElement("E");
+    ClassElement F = env.getElement("F");
+    ClassElement G = env.getElement("G");
+    ClassElement H = env.getElement("H");
+    ClassElement I = env.getElement("I");
+
+    void checkClass(ClassElement cls,
+                    List<ClassElement> subtypes) {
+      ClassSet node = world.getClassSet(cls);
+      print('$cls:\n${node}');
+      Expect.listEquals(subtypes,
+          node.subtypes().toList(),
+          "Unexpected subtypes of ${cls.name}:\n"
+          "Expected: $subtypes\n"
+          "Found   : ${node.subtypes().toList()}");
+    }
+
+    checkClass(A, [A, C, E, F, G, B, D, H, I]);
+    checkClass(B, [B, D, E]);
+    checkClass(C, [C, E, F, G, H, B, D, I]);
+    checkClass(D, [D]);
+    checkClass(E, [E]);
+    checkClass(F, [F]);
+    checkClass(G, [G]);
+    checkClass(H, [H, I]);
+    checkClass(I, [I]);
+  }));
+}