Remove barback from the repo.

pkg/barback/test/transformer/many_to_one.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.many_to_one;
-
-import 'dart:async';
-
-import 'package:barback/barback.dart';
-
-import 'mock.dart';
-
-/// A transformer that uses the contents of a file to define the other inputs.
-///
-/// Outputs a file with the same name as the primary but with an "out"
-/// extension containing the concatenated contents of all non-primary inputs.
-class ManyToOneTransformer extends MockTransformer {
-  final String extension;
-
-  /// Creates a transformer that consumes assets with [extension].
-  ///
-  /// That file contains a comma-separated list of paths and it will input
-  /// files at each of those paths.
-  ManyToOneTransformer(this.extension);
-
-  bool doIsPrimary(AssetId id) => id.extension == ".$extension";
-
-  Future doApply(Transform transform) {
-    return getPrimary(transform)
-        .then((primary) => primary.readAsString())
-        .then((contents) {
-      // Get all of the included inputs.
-      return Future.wait(contents.split(",").map((path) {
-        var id;
-        if (path.contains("|")) {
-          id = new AssetId.parse(path);
-        } else {
-          id = new AssetId(transform.primaryInput.id.package, path);
-        }
-        return getInput(transform, id).then((input) => input.readAsString());
-      }));
-    }).then((outputs) {
-      var id = transform.primaryInput.id.changeExtension(".out");
-      transform.addOutput(new Asset.fromString(id, outputs.join()));
-    });
-  }
-
-  String toString() => "many->1 $extension";
-}