Link to stable-errors site from pub-build messages on the command line.

pkg/code_transformers/lib/messages/build_logger.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 code_transformers.messages.messages_logger;
 
 import 'dart:async';
 import 'dart:convert' show JSON;
 
 import 'package:barback/barback.dart';
@@ skipping 22 matching lines @@
   /// Underling transform that is currently active.
   final Transform _transform;
 
   /// Logs created during the current transform.
   final LogEntryTable _logs = new LogEntryTable();
 
   /// Whether to use `warning` or `error` when forwarding error messages to the
   /// underlying logger in `_transform.logger`.
   final bool convertErrorsToWarnings;
 
-  BuildLogger(this._transform, {this.convertErrorsToWarnings: false});
+  /// Uri prefix to link for additional details. If set, messages logged through
+  /// this logger will contain an additional sentence, telling users to find
+  /// more details at `$detailsUri#packagename_id`.
+  final String detailsUri;
+
+  BuildLogger(this._transform, {this.convertErrorsToWarnings: false,
+      this.detailsUri});
 
   /// Records a message at the fine level. If [msg] is a [Message] it is
   /// recorded directly, otherwise it is first converted to a [String].
   void fine(msg, {AssetId asset, SourceSpan span}) {
     msg = msg is Message ? msg : new Message.unknown('$msg');
-    _transform.logger.fine(msg.snippet, asset: asset, span: span);
+    _transform.logger.fine(_snippet(msg), asset: asset, span: span);
     _logs.add(new BuildLogEntry(msg, span, LogLevel.FINE.name));
   }
 
   /// Records a message at the info level. If [msg] is a [Message] it is
   /// recorded directly, otherwise it is first converted to a [String].
   void info(msg, {AssetId asset, SourceSpan span}) {
     msg = msg is Message ? msg : new Message.unknown('$msg');
-    _transform.logger.info(msg.snippet, asset: asset, span: span);
+    _transform.logger.info(_snippet(msg), asset: asset, span: span);
     _logs.add(new BuildLogEntry(msg, span, LogLevel.INFO.name));
   }
 
   /// Records a warning message. If [msg] is a [Message] it is recorded
   /// directly, otherwise it is first converted to a [String].
   void warning(msg, {AssetId asset, SourceSpan span}) {
     msg = msg is Message ? msg : new Message.unknown('$msg');
-    _transform.logger.warning(msg.snippet, asset: asset, span: span);
+    _transform.logger.warning(_snippet(msg), asset: asset, span: span);
     _logs.add(new BuildLogEntry(msg, span, LogLevel.WARNING.name));
   }
 
   /// Records an error message. If [msg] is a [Message] it is recorded
   /// directly, otherwise it is first converted to a [String].
   void error(msg, {AssetId asset, SourceSpan span}) {
     msg = msg is Message ? msg : new Message.unknown('$msg');
     if (convertErrorsToWarnings) {
-      _transform.logger.warning(msg.snippet, asset: asset, span: span);
+      _transform.logger.warning(_snippet(msg), asset: asset, span: span);
     } else {
-      _transform.logger.error(msg.snippet, asset: asset, span: span);
+      _transform.logger.error(_snippet(msg), asset: asset, span: span);
     }
     _logs.add(new BuildLogEntry(msg, span, LogLevel.ERROR.name));
   }
 
+  String _snippet(Message msg) {
+    var s = msg.snippet;
+    if (detailsUri == null) return s;
+    var dot = s.endsWith('.') || s.endsWith('!') || s.endsWith('?') ? '' : '.';
+    var hashTag = '${msg.id.package}_${msg.id.id}';
+    return '$s$dot See $detailsUri#$hashTag for details.';
+  }
+
   /// Outputs the log data to a JSON serialized file.
   Future writeOutput() {
     return _getNextLogAssetPath().then((path) {
       _transform.addOutput(new Asset.fromString(path,
           JSON.encode(_logs)));
     });
   }
 
   // Each phase outputs a new log file with an incrementing # appended, this
   // figures out the next # to use.
@@ skipping 31 matching lines @@
   }
 
   // Reads all logs for an asset and adds them to this loggers log output.
   Future addLogFilesFromAsset(AssetId id, [int nextNumber = 1]) {
     return _readLogFilesForAsset(id, _transform, _logs);
   }
 }
 
 /// Extension used for assets that contained serialized logs.
 const String LOG_EXTENSION = '._buildLogs';