Implement FileState.hashCode/==.

pkg/analyzer/lib/src/dart/analysis/file_state.dart

 // Copyright (c) 2016, 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.
 
 import 'dart:convert';
 import 'dart:typed_data';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/error/listener.dart';
@@ skipping 101 matching lines @@
   /**
    * Return the list of all direct dependencies.
    */
   List<FileState> get dependencies => _dependencies;
 
   /**
    * The list of files this file exports.
    */
   List<FileState> get exportedFiles => _exportedFiles;
 
+  @override
+  int get hashCode => uri.hashCode;
+
   /**
    * The list of files this file imports.
    */
   List<FileState> get importedFiles => _importedFiles;
 
   /**
    * Return information about line in the file.
    */
   LineInfo get lineInfo => _lineInfo;
 
   /**
    * The list of files this library file references as parts.
    */
   List<FileState> get partedFiles => _partedFiles;
 
   /**
    * The [UnlinkedUnit] of the file.
    */
   UnlinkedUnit get unlinked => _unlinked;
 
+  @override
+  bool operator ==(Object other) {
+    return other is FileState && other.uri == uri;
+  }
+
   /**
    * Return a new parsed unresolved [CompilationUnit].
    */
   CompilationUnit parse(AnalysisErrorListener errorListener) {
     AnalysisOptions analysisOptions = _fsState._analysisOptions;
 
     CharSequenceReader reader = new CharSequenceReader(content);
     Scanner scanner = new Scanner(source, reader, errorListener);
     scanner.scanGenericMethodComments = analysisOptions.strongMode;
     Token token = scanner.tokenize();
@@ skipping 246 matching lines @@
     FileState canonicalFile = getFileForPath(path);
     List<FileState> allFiles = _pathToFiles[path].toList();
     if (allFiles.length == 1) {
       return allFiles;
     }
     return allFiles
       ..remove(canonicalFile)
       ..insert(0, canonicalFile);
   }
 }