Issue 21613. Fix for renaming FieldFormalParameterElement.

pkg/analysis_server/test/services/refactoring/rename_class_member_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.refactoring.rename_class_member;
 
 import 'package:analysis_server/src/protocol.dart';
 import 'package:unittest/unittest.dart';
 
 import '../../reflective_tests.dart';
@@ skipping 391 matching lines @@
     refactoring.newName = 'newName';
     // validate change
     return assertSuccessfulRefactoring('''
 class A {
   final newName;
   A(this.newName);
 }
 ''');
   }
 
+  test_createChange_FieldElement_fieldFormalParameter_named() {
+    indexTestUnit('''
+class A {
+  final test;
+  A({this.test});
+}
+main() {
+  new A(test: 42);
+}
+''');
+    // configure refactoring
+    createRenameRefactoringAtString('test;');
+    expect(refactoring.refactoringName, 'Rename Field');
+    expect(refactoring.oldName, 'test');
+    refactoring.newName = 'newName';
+    // validate change
+    return assertSuccessfulRefactoring('''
+class A {
+  final newName;
+  A({this.newName});
+}
+main() {
+  new A(newName: 42);
+}
+''');
+  }
+
   test_createChange_FieldElement_invocation() {
     indexTestUnit('''
 typedef F(a);
 class A {
   F test;
   main() {
     test(1);
   }
 }
 main() {
@@ skipping 283 matching lines @@
     // validate change
     return assertSuccessfulRefactoring('''
 class A<NewName> {
   NewName field;
   List<NewName> items;
   NewName method(NewName p) => null;
 }
 ''');
   }
 }