Merge pull request #581 from kevmoo/polymer

lib/src/messages.dart

Index: lib/src/messages.dart
diff --git a/lib/src/messages.dart b/lib/src/messages.dart
index 42032b3311ea63613b9c584ede5729a31aa2e1a8..5dc62475fe0279207e9abe9ce0e4af461417cf77 100644
--- a/lib/src/messages.dart
+++ b/lib/src/messages.dart
@@ -6,6 +6,7 @@ library messages;
 
 import 'dart:json' as json;
 
+import 'package:barback/barback.dart' show TransformLogger;
 import 'package:source_maps/span.dart' show Span;
 import 'package:logging/logging.dart' show Level;
 
@@ -70,7 +71,7 @@ class Message {
  * This class tracks and prints information, warnings, and errors emitted by the
  * compiler.
  */
-class Messages {
+class Messages implements TransformLogger {
   final CompilerOptions options;
   final bool shouldPrint;
 
@@ -101,7 +102,7 @@ class Messages {
   }
 
   /** [message] is considered a static compile-time error by the Dart lang. */
-  void error(String message, Span span) {
+  void error(String message, [Span span]) {
     var msg = new Message(Level.SEVERE, message, span: span,
         useColors: options.useColors);
 
@@ -110,7 +111,7 @@ class Messages {
   }
 
   /** [message] is considered a type warning by the Dart lang. */
-  void warning(String message, Span span) {
+  void warning(String message, [Span span]) {
     if (options.warningsAsErrors) {
       error(message, span);
     } else {
@@ -134,7 +135,7 @@ class Messages {
    * [message] at [span] will tell the user about what the compiler
    * is doing.
    */
-  void info(String message, Span span) {
+  void info(String message, [Span span]) {
     var msg = new Message(Level.INFO, message, span: span,
         useColors: options.useColors);