add logging support for exceptions

pkg/logging/test/logging_test.dart

 // Copyright (c) 2012, 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 logging_test;
 
 import 'package:logging/logging.dart';
 import 'package:unittest/unittest.dart';
 
@@ skipping 210 matching lines @@
         'FINEST: 1',
         'FINER: 2',
         'FINE: 3',
         'CONFIG: 4',
         'INFO: 5',
         'WARNING: 6',
         'SEVERE: 7',
         'SHOUT: 8']));
     });
 
+    test('logging methods store exception', () {
+      root.level = Level.ALL;
+      var rootMessages = [];
+      root.onRecord.listen((r) {
+        rootMessages.add('${r.level}: ${r.message} ${r.exception}');
+      });
+
+      root.finest('1');
+      root.finer('2');
+      root.fine('3');
+      root.config('4');
+      root.info('5');
+      root.warning('6');
+      root.severe('7');
+      root.shout('8');
+      root.finest('1', 'a');
+      root.finer('2', 'b');
+      root.fine('3', ['c']);
+      root.config('4', 'd');
+      root.info('5', 'e');
+      root.warning('6', 'f');
+      root.severe('7', 'g');
+      root.shout('8', 'h');
+
+      expect(rootMessages, equals([
+        'FINEST: 1 null',
+        'FINER: 2 null',
+        'FINE: 3 null',
+        'CONFIG: 4 null',
+        'INFO: 5 null',
+        'WARNING: 6 null',
+        'SEVERE: 7 null',
+        'SHOUT: 8 null',
+        'FINEST: 1 a',
+        'FINER: 2 b',
+        'FINE: 3 [c]',
+        'CONFIG: 4 d',
+        'INFO: 5 e',
+        'WARNING: 6 f',
+        'SEVERE: 7 g',
+        'SHOUT: 8 h']));
+    });
+
     test('message logging - no hierarchy', () {
       root.level = Level.WARNING;
       var rootMessages = [];
       var aMessages = [];
       var cMessages = [];
       c.onRecord.listen((record) {
         cMessages.add('${record.level}: ${record.message}');
       });
       a.onRecord.listen((record) {
         aMessages.add('${record.level}: ${record.message}');
@@ skipping 86 matching lines @@
             'SHOUT: 10']));
 
       expect(cMessages, equals([
             // 1 - 7 are lower in the hierarchy
             // 'FINE: 8' is not loggable
             'WARNING: 9',
             'SHOUT: 10']));
     });
   });
 }