pkg/barback/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);

  Future<bool> doIsPrimary(Asset asset) => new Future.value(true);

  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;
    });
  }
}