Record HAS_ANCESTOR relations into index.

pkg/analysis_server/test/services/search/search_engine_test.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 test.services.src.search.search_engine;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/services/index/index.dart';
 import 'package:analysis_server/src/services/index/local_memory_index.dart';
@@ skipping 59 matching lines @@
 class SearchEngineImplTest extends AbstractSingleUnitTest {
   Index index;
   SearchEngineImpl searchEngine;
 
   void setUp() {
     super.setUp();
     index = createLocalMemoryIndex();
     searchEngine = new SearchEngineImpl(index);
   }
 
+  Future test_searchAllSubtypes() {
+    _indexTestUnit('''
+class T {}
+class A extends T {}
+class B extends A {}
+class C implements B {}
+''');
+    ClassElement element = findElement('T');
+    ClassElement elementA = findElement('A');
+    ClassElement elementB = findElement('B');
+    ClassElement elementC = findElement('C');
+    var expected = [
+      _expectId(elementA, MatchKind.DECLARATION, 'A extends T'),
+      _expectId(elementB, MatchKind.DECLARATION, 'B extends A'),
+      _expectId(elementC, MatchKind.DECLARATION, 'C implements B')
+    ];
+    return searchEngine.searchAllSubtypes(element).then((matches) {
+      _assertMatches(matches, expected);
+    });
+  }
+
   Future test_searchElementDeclarations() {
     _indexTestUnit('''
 class A {
   test() {}
 }
 class B {
   int test = 1;
   main() {
     int test = 2;
   }
@@ skipping 557 matching lines @@
         .then((List<SearchMatch> matches) {
       _assertMatches(matches, expectedMatches);
     });
   }
 
   static void _assertMatches(
       List<SearchMatch> matches, List<ExpectedMatch> expectedMatches) {
     expect(matches, unorderedEquals(expectedMatches));
   }
 }