Suppress lints on synthetic nodes/tokens (#193).

lib/src/linter.dart

 // Copyright (c) 2015, 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 linter.src.linter;
 
 import 'dart:io';
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/src/generated/engine.dart'
@@ skipping 243 matching lines @@
   ProjectVisitor getProjectVisitor() => null;
 
   /// Return a visitor to be passed to pubspecs to perform lint
   /// analysis.
   /// Lint errors are reported via this [Linter]'s error [reporter].
   PubspecVisitor getPubspecVisitor() => null;
 
   @override
   AstVisitor getVisitor() => null;
 
-  void reportLint(AstNode node) {
-    if (node != null) {
+  void reportLint(AstNode node, {bool ignoreSyntheticNodes: true}) {
+    if (node != null && (!node.isSynthetic || !ignoreSyntheticNodes)) {
       reporter.reportErrorForNode(new _LintCode(name, description), node, []);
     }
   }
 
-  void reportLintForToken(Token token) {
-    if (token != null) {
+  void reportLintForToken(Token token, {bool ignoreSyntheticTokens: true}) {
+    if (token != null && (!token.isSynthetic || !ignoreSyntheticTokens)) {

[Brian Wilkerson, 2016/03/01 21:26:54]

Interesting. In the parser, when we're not ignoring synthetic tokens, we attach
the error to the first non-synthetic token preceding the synthetic one because
synthetic tokens always have a length of zero.

[pquitslund, 2016/03/01 21:30:01]

Hmmmm.  That is interesting.  Maybe I should just remove this logic?  I'm only
seeing the synthetic nodes in the wild anyway...

[Brian Wilkerson, 2016/03/01 21:38:55]

It seems consistent to disable lints on synthetic tokens; some future lints will
undoubtedly want to report against non-identifier tokens.

But given that synthetic tokens always have zero length, it's kind of hard for
editors to highlight them. Maybe just a TODO for now so that we don't forget.

       reporter.reportErrorForToken(new _LintCode(name, description), token, []);
     }
   }
 
   void reportPubLint(PSNode node) {
     Source source = createSource(node.span.sourceUrl);
 
     // Cache error and location info for creating AnalysisErrorInfos
     // Note that error columns are 1-based
     var error = new AnalysisError(source, node.span.start.column + 1,
@@ skipping 144 matching lines @@
 }
 
 class _LintCode extends LintCode {
   static final registry = <String, LintCode>{};
 
   factory _LintCode(String name, String message) => registry.putIfAbsent(
       name + message, () => new _LintCode._(name, message));
 
   _LintCode._(String name, String message) : super(name, message);
 }