Expose aggregate transformers in pub.

dart/sdk/lib/_internal/pub/test/transformer/loads_a_lazy_aggregate_transformer_test.dart

Index: dart/sdk/lib/_internal/pub/test/transformer/loads_a_lazy_aggregate_transformer_test.dart
diff --git a/dart/sdk/lib/_internal/pub/test/transformer/loads_a_lazy_aggregate_transformer_test.dart b/dart/sdk/lib/_internal/pub/test/transformer/loads_a_lazy_aggregate_transformer_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..62b4ff692adc12c0b247f15fec38ef0b756b56de
--- /dev/null
+++ b/dart/sdk/lib/_internal/pub/test/transformer/loads_a_lazy_aggregate_transformer_test.dart
@@ -0,0 +1,72 @@
+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS d.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 pub_tests;
+
+import '../descriptor.dart' as d;
+import '../test_pub.dart';
+import '../serve/utils.dart';
+
+const AGGREGATE_TRANSFORMER = """
+import 'dart:async';
+
+import 'package:barback/barback.dart';
+import 'package:path/path.dart' as p;
+
+class ManyToOneTransformer extends AggregateTransformer
+    implements LazyAggregateTransformer {
+  ManyToOneTransformer.asPlugin();
+
+  String classifyPrimary(AssetId id) {
+    if (id.extension != '.txt') return null;
+    return p.url.dirname(id.path);
+  }
+
+  Future apply(AggregateTransform transform) {
+    return transform.primaryInputs.toList().then((assets) {
+      assets.sort((asset1, asset2) => asset1.id.path.compareTo(asset2.id.path));
+      return Future.wait(assets.map((asset) => asset.readAsString()));
+    }).then((contents) {
+      var id = new AssetId(transform.package,
+          p.url.join(transform.key, 'out.txt'));
+      transform.addOutput(new Asset.fromString(id, contents.join('\\n')));
+    });
+  }
+
+  void declareOutputs(DeclaringAggregateTransform transform) {
+    transform.declareOutput(new AssetId(transform.package,
+        p.url.join(transform.key, 'out.txt')));
+  }
+}
+""";
+
+main() {
+  initConfig();
+  withBarbackVersions(">=0.14.1-dev", () {
+    integration("loads a lazy aggregate transformer", () {
+      d.dir(appPath, [
+        d.pubspec({
+          "name": "myapp",
+          "transformers": ["myapp"]
+        }),
+        d.dir("lib", [
+          d.file("transformer.dart", AGGREGATE_TRANSFORMER),
+        ]),
+        d.dir("web", [
+          d.file("foo.txt", "foo"),
+          d.file("bar.txt", "bar")
+        ])
+      ]).create();
+
+      createLockFile('myapp', pkg: ['barback']);
+
+      var server = pubServe();
+      // The transformer should preserve laziness.
+      server.stdout.expect("Build completed successfully");
+
+      requestShouldSucceed("out.txt", "bar\nfoo");
+      endPubServe();
+    });
+  });
+}