Ignore bogus links, such as those created by emacs for files being edited.

pkg/analysis_server/lib/src/resource.dart

 // Copyright (c) 2014, 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 resource;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:io' as io;
 
@@ skipping 155 matching lines @@
   MemoryResourceException(this.path, this.message);
 
   @override
   String toString() {
     return "MemoryResourceException(path=$path; message=$message)";
   }
 }
 
 
 /**
+ * An in-memory implementation of [File] which acts like a symbolic link to a
+ * non-existent file.
+ */
+class _MemoryDummyLink extends _MemoryResource implements File {
+  _MemoryDummyLink(MemoryResourceProvider provider, String path) :
+      super(provider, path);
+
+  @override
+  Source createSource(UriKind uriKind) {
+    throw new MemoryResourceException(path, "File '$path' could not be read");
+  }
+
+  String get _content {
+    throw new MemoryResourceException(path, "File '$path' could not be read");
+  }
+
+  int get _timestamp => _provider._pathToTimestamp[path];
+
+  @override
+  bool get exists => false;
+}
+
+
+/**
  * An in-memory implementation of [Source].
  */
 class _MemoryFileSource implements Source {
   final _MemoryFile _file;
 
   final UriKind uriKind;
 
   _MemoryFileSource(this._file, this.uriKind);
 
   @override
@@ skipping 143 matching lines @@
     path = posix.normalize(path);
     newFolder(posix.dirname(path));
     _MemoryFile file = new _MemoryFile(this, path);
     _pathToResource[path] = file;
     _pathToContent[path] = content;
     _pathToTimestamp[path] = nextStamp++;
     _notifyWatchers(path, ChangeType.ADD);
     return file;
   }
 
+  /**
+   * Create a resource representing a dummy link (that is, a File object which
+   * appears in its parent directory, but whose `exists` property is false)
+   */
+  File newDummyLink(String path) {
+    path = posix.normalize(path);
+    newFolder(posix.dirname(path));
+    _MemoryDummyLink link = new _MemoryDummyLink(this, path);
+    _pathToResource[path] = link;
+    _pathToTimestamp[path] = nextStamp++;
+    _notifyWatchers(path, ChangeType.ADD);
+    return link;
+  }
+
   void _notifyWatchers(String path, ChangeType changeType) {
     _pathToWatchers.forEach((String watcherPath, List<StreamController<WatchEvent>> streamControllers) {
       if (posix.isWithin(watcherPath, path)) {
         for (StreamController<WatchEvent> streamController in streamControllers) {
           streamController.add(new WatchEvent(changeType, path));
         }
       }
     });
   }
 
@@ skipping 169 matching lines @@
   }
 
   /**
    * Return `true` if the given URI is a `file` URI.
    *
    * @param uri the URI being tested
    * @return `true` if the given URI is a `file` URI
    */
   static bool _isFileUri(Uri uri) => uri.scheme == _FILE_SCHEME;
 }