Index and search of import prefixes.

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 421 matching lines @@
 }
 ''');
     LabelElement element = findElement('label');
     Element mainElement = findElement('main');
     var expected = [
         _expectId(mainElement, MatchKind.REFERENCE, 'label; // 1'),
         _expectId(mainElement, MatchKind.REFERENCE, 'label; // 2')];
     return _verifyReferences(element, expected);
   }
 
+  Future test_searchReferences_PrefixElement() {
+    _indexTestUnit('''
+import 'dart:async' as ppp;
+main() {
+  ppp.Future a;
+  ppp.Stream b;
+}
+''');
+    PrefixElement element = findNodeElementAtString('ppp;');
+    Element elementA = findElement('a');
+    Element elementB = findElement('b');
+    var expected = [
+        _expectId(elementA, MatchKind.REFERENCE, 'ppp.Future'),
+        _expectId(elementB, MatchKind.REFERENCE, 'ppp.Stream')];
+    return _verifyReferences(element, expected);
+  }
+
   Future test_searchReferences_MethodElement() {
     _indexTestUnit('''
 class A {
   m() {}
   main() {
     m(); // 1
     this.m(); // 2
     print(m); // 3
     print(this.m); // 4
   }
@@ skipping 225 matching lines @@
         pattern).then((List<SearchMatch> matches) {
       _assertMatches(matches, expectedMatches);
     });
   }
 
   static void _assertMatches(List<SearchMatch> matches,
       List<ExpectedMatch> expectedMatches) {
     expect(matches, unorderedEquals(expectedMatches));
   }
 }