When user renames 'prefix' in 'prefix.Class' she actually wants to rename ImportElement.

pkg/analysis_server/test/edit/refactoring_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.edit.refactoring;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/edit/edit_domain.dart';
 import 'package:analysis_server/src/protocol.dart';
 import 'package:analysis_testing/reflective_tests.dart';
 import 'package:unittest/unittest.dart' hide ERROR;
 
 import '../analysis_abstract.dart';
 
 
 main() {
   groupSep = ' | ';
   runReflectiveTests(GetAvailableRefactoringsTest);
 }
 
 
 @ReflectiveTestCase()
 class GetAvailableRefactoringsTest extends AbstractAnalysisTest {
+  /**
+   * Tests that there is a RENAME refactoring available at the [search] offset.
+   */
   Future assertHasRenameRefactoring(String code, String search) {
     addTestFile(code);
     return waitForTasksFinished().then((_) {
       List<String> kinds = getAvailableRefactorings(search);
       expect(kinds, contains(RefactoringKind.RENAME));
     });
   }
 
+  /**
+   * Returns the list of available refactorings of the offset of [search] with
+   * [length] characters selected.
+   */
   List<String> getAvailableRefactorings(String search, [int length = 0]) {
     Request request = new Request('0', EDIT_GET_AVAILABLE_REFACTORINGS);
     request.setParameter(FILE, testFile);
     request.setParameter(OFFSET, findOffset(search));
     request.setParameter(LENGTH, length);
     Response response = handleSuccessfulRequest(request);
     return response.getResult(KINDS);
   }
 
   @override
@@ skipping 34 matching lines @@
 
   Future test_rename_hasElement_importElement_directive() {
     return assertHasRenameRefactoring('''
 import 'dart:math' as math;
 main() {
   math.PI;
 }
 ''', 'import ');
   }
 
+  Future test_rename_hasElement_importElement_prefixDecl() {
+    return assertHasRenameRefactoring('''
+import 'dart:math' as math;
+main() {
+  math.PI;
+}
+''', 'math;');
+  }
+
+  Future test_rename_hasElement_importElement_prefixRef() {
+    return assertHasRenameRefactoring('''
+import 'dart:async' as test;
+import 'dart:math' as test;
+main() {
+  test.PI;
+}
+''', 'test.PI;');
+  }
+
   Future test_rename_hasElement_instanceGetter() {
     return assertHasRenameRefactoring('''
 class A {
   get test => 0;
 }
 main(A a) {
   a.test;
 }
 ''', 'test;');
   }
@@ skipping 40 matching lines @@
 main() {
   // not an element
 }
 ''');
     return waitForTasksFinished().then((_) {
       List<String> kinds = getAvailableRefactorings('// not an element');
       expect(kinds, isNot(contains(RefactoringKind.RENAME)));
     });
   }
 }