Support new import rules.

tests/compiler/dart2js/message_kind_helper.dart

 // Copyright (c) 2013, 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.
 
 library dart2js.test.message_kind_helper;
 
 import 'package:expect/expect.dart';
 import 'dart:async';
 
 import '../../../sdk/lib/_internal/compiler/implementation/dart2jslib.dart' show
     Compiler,
     MessageKind;
 
 import 'memory_compiler.dart';
 
 const String ESCAPE_REGEXP = r'[[\]{}()*+?.\\^$|]';
 
 Future<Compiler> check(MessageKind kind, Compiler cachedCompiler) {
   Expect.isNotNull(kind.howToFix);
   Expect.isFalse(kind.examples.isEmpty);
 
-  for (String example in kind.examples) {
+  return Future.forEach(kind.examples, (example) {
+    if (example is String) {
+      example = {'main.dart': example};
+    } else {
+      Expect.isTrue(example is Map,
+                    "Example must be either a String or a Map.");
+      Expect.isTrue(example.containsKey('main.dart'),
+                    "Example map must contain a 'main.dart' entry.");
+    }
     List<String> messages = <String>[];
     void collect(Uri uri, int begin, int end, String message, kind) {
       if (kind.name == 'verbose info') {
         return;
       }
       messages.add(message);
     }
 
     Compiler compiler = compilerFor(
-        {'main.dart': example},
+        example,
         diagnosticHandler: collect,
         options: ['--analyze-only'],
         cachedCompiler: cachedCompiler);
 
     return compiler.run(Uri.parse('memory:main.dart')).then((_) {
 
       Expect.isFalse(messages.isEmpty, 'No messages in """$example"""');
 
       String expectedText = !kind.hasHowToFix
           ? kind.template : '${kind.template}\n${kind.howToFix}';
       String pattern = expectedText.replaceAllMapped(
           new RegExp(ESCAPE_REGEXP), (m) => '\\${m[0]}');
       pattern = pattern.replaceAll(new RegExp(r'#\\\{[^}]*\\\}'), '.*');
 
       // TODO(johnniwinther): Extend MessageKind to contain information on
       // where info messages are expected.
       bool messageFound = false;
       for (String message in messages) {
         if (new RegExp('^$pattern\$').hasMatch(message)) {
           messageFound = true;
         }
       }
       Expect.isTrue(messageFound, '"$pattern" does not match any in $messages');
-      return compiler;
+      cachedCompiler = compiler;
     });
-  }
-
-  return new Future<Compiler>.sync(cachedCompiler);
+  }).then((_) => cachedCompiler);
 }