Fix BuilderTransformer to forward logs to the TransformLogger

CHANGELOG.md

@@ -1,8 +1,11 @@
 # Changelog
 
+## 0.3.0+3
+- Fixed BuilderTransformer so that logs are passed on to the TransformLogger.
+
 ## 0.3.0+2
 - Enable serving files outside the server root by default (enables serving
-  files from other packages). 
+  files from other packages).
 
 ## 0.3.0+1
 - Fix an AssetGraph bug where generated nodes might be created as non-generated

lib/src/transformer/transformer.dart

@@ -6,6 +6,7 @@ import 'dart:convert';
 
 import 'package:barback/barback.dart' as barback show AssetId;
 import 'package:barback/barback.dart' hide Asset, AssetId;
+import 'package:logging/logging.dart';
 
 import '../asset/asset.dart' as build;
 import '../asset/id.dart' as build;
@@ -72,8 +73,21 @@ abstract class BuilderTransformer implements Transformer, DeclaringTransformer {
       // Run the build step.
       var buildStep =
           new BuildStepImpl(input, expected, reader, writer, input.id.package);
+      Logger.root.level = Level.ALL;
+      var logSubscription = buildStep.logger.onRecord.listen((LogRecord log) {
+        if (log.level <= Level.CONFIG) {
+          transform.logger.fine(log.message);
+        } else if (log.level <= Level.INFO) {
+          transform.logger.info(log.message);
+        } else if (log.level <= Level.WARNING) {
+          transform.logger.warning(log.message);
+        } else {
+          transform.logger.error(log.message);
+        }
+      });
       await builder.build(buildStep);
       await buildStep.complete();
+      await logSubscription.cancel();
     }));
   }
 

pubspec.yaml

@@ -1,5 +1,5 @@
 name: build
-version: 0.3.0+2
+version: 0.3.0+3
 description: A build system for Dart.
 author: Dart Team <[email protected]>
 homepage: https://github.com/dart-lang/build

test/transformer/transformer_test.dart

@@ -2,6 +2,9 @@
 // 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.
 @TestOn('vm')
+import 'dart:async';
+
+import 'package:build/build.dart';
 import 'package:test/test.dart';
 import 'package:transformer_test/utils.dart';
 
@@ -112,6 +115,28 @@ void main() {
         _fileExistsError("CopyBuilder", ["a|web/a.txt.copy"]),
       ],
       expectBarbackErrors: true);
+
+  testPhases('loggers log errors', [
+    [
+      new GenericBuilderTransformer([new LoggingCopyBuilder()])
+    ],
+  ], {
+    'a|web/a.txt': 'hello',
+  }, {}, messages: [
+    'warning: Warning!',
+    'error: Error!',
+  ]);
+}
+
+class LoggingCopyBuilder extends CopyBuilder {
+  LoggingCopyBuilder() : super();
+
+  @override
+  Future build(BuildStep buildStep) async {
+    await super.build(buildStep);
+    buildStep.logger.warning('Warning!');
+    buildStep.logger.severe('Error!');
+  }
 }
 
 String _fileExistsError(String builder, List<String> files) {