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';
@@ skipping 68 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() {

[Brian Wilkerson, 2014/08/18 21:42:34]

Possibly test an ambiguous case.

[scheglov, 2014/08/18 21:49:41]

Done.

+    return assertHasRenameRefactoring('''
+import 'dart:math' as math;
+main() {
+  math.PI;
+}
+''', 'math.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)));
     });
   }
 }