Issue 22188. Verify that none or all execution flows return.

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/correction/status.dart';
@@ skipping 422 matching lines @@
 // end
   print(v);
 }
 ''');
     _createRefactoringForStartEndComments();
     return _assertConditionsFatal(
         "Ambiguous return value: Selected block contains assignment(s) to "
             "local variables and return statement.");
   }
 
+  test_bad_statements_return_notAllExecutionFlows() {
+    indexTestUnit('''
+main(int p) {
+// start
+  if (p == 0) {
+    return;
+  }
+// end
+  print(p);
+}
+''');
+    _createRefactoringForStartEndComments();
+    return _assertConditionsError(
+        "Selected statements contain a return statement, but not all possible "

[Paul Berry, 2015/02/10 18:25:16]

Nit: it would be nice to put this string in a const somewhere so that we don't
have to duplicate it between the implementation and the test.

+        "execuion flows end in a return. Semantics may not be preserved.");
+  }
+
   test_bad_switchCase() {
     indexTestUnit('''
 main() {
   switch (1) { 
 // start
     case 0: break;
 // end
   }
 }
 ''');
@@ skipping 1998 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();
   }
 }