Issue 18296. Harden the name checks.

pkg/analysis_server/test/services/refactoring/extract_method_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.extract_method;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart';
 import 'package:analysis_server/src/services/refactoring/extract_method.dart';
@@ skipping 325 matching lines @@
     indexTestUnit('''
 main() {
 // start
   print(0);
 // end
 }
 ''');
     _createRefactoringForStartEndComments();
     refactoring.name = 'bad-name';
     // check conditions
-    return _assertConditionsError("Method name must not contain '-'.");
+    return _assertConditionsFatal("Method name must not contain '-'.");
   }
 
   test_bad_notSameParent() {
     indexTestUnit('''
 main() {
   while (false) 
 // start
   { 
   } 
   print(0);
@@ skipping 1951 matching lines @@
    * Returns a deep copy of [refactoring] parameters.
    * There was a bug masked by updating parameter instances shared between the
    * refactoring and the test.
    */
   List<RefactoringMethodParameter> _getParametersCopy() {
     return refactoring.parameters.map((p) {
       return new RefactoringMethodParameter(p.kind, p.type, p.name, id: p.id);
     }).toList();
   }
 }