Run pub tests against older versions of barback.

third_party/pkg/barback-0.13.0/test/transformer/bad.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 barback.test.transformer.bad;
 
+import 'dart:async';
+
 import 'package:barback/barback.dart';
+import 'package:barback/src/utils.dart';
 
 import 'mock.dart';
 
 /// A transformer that throws an exception when run, after generating the
 /// given outputs.
 class BadTransformer extends MockTransformer {
   /// The error it throws.
   static const ERROR = "I am a bad transformer!";
 
   /// The list of asset names that it should output.
   final List<String> outputs;
 
   BadTransformer(this.outputs);
 
-  bool doIsPrimary(AssetId id) => true;
+  Future<bool> doIsPrimary(AssetId id) => new Future.value(true);
 
-  void doApply(Transform transform) {
-    // Create the outputs first.
-    for (var output in outputs) {
-      var id = new AssetId.parse(output);
-      transform.addOutput(new Asset.fromString(id, output));
-    }
+  Future doApply(Transform transform) {
+    return newFuture(() {
+      // Create the outputs first.
+      for (var output in outputs) {
+        var id = new AssetId.parse(output);
+        transform.addOutput(new Asset.fromString(id, output));
+      }
 
-    // Then fail.
-    throw ERROR;
+      // Then fail.
+      throw ERROR;
+    });
   }
 }