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 406 matching lines @@
   print(1);
 // end
 }
 ''');
     _createRefactoringForStartEndString('print(0', 'rint(1)');
     return _assertConditionsFatal(
         "The selection does not cover a set of statements or an expression. "
             "Extend selection to a valid range.");
   }
 
+  test_bad_statements_exit_notAllExecutionFlows() {
+    indexTestUnit('''
+main(int p) {
+// start
+  if (p == 0) {
+    return;
+  }
+// end
+  print(p);
+}
+''');
+    _createRefactoringForStartEndComments();
+    return _assertConditionsError(ExtractMethodRefactoringImpl.ERROR_EXITS);
+  }
+
   test_bad_statements_return_andAssignsVariable() {
     indexTestUnit('''
 main() {
 // start
   var v = 0;
   return 42;
 // end
   print(v);
 }
 ''');
@@ skipping 1636 matching lines @@
 }
 
 void res() {
   if (true) {
     print(0);
   }
 }
 ''');
   }
 
+  test_statements_exit_throws() async {
+    indexTestUnit('''
+main(int p) {
+// start
+  if (p == 0) {
+    return;
+  }
+  throw 'boo!';
+// end
+}
+''');
+    _createRefactoringForStartEndComments();
+    await assertRefactoringConditionsOK();
+  }
+
   test_statements_inSwitchMember() {
     indexTestUnit('''
 class A {
   foo(int p) {
     switch (p) {
       case 0:
 // start
         print(0);
 // end
         break;
@@ skipping 192 matching lines @@
   return 42;
 }
 ''');
   }
 
   test_statements_return_multiple_sameElementDifferentTypeArgs() {
     indexTestUnit('''
 main(bool b) {
 // start
   if (b) {
+    print(true);
     return <int>[];
   } else {
+    print(false);
     return <String>[];
   }
 // end
 }
 ''');
     _createRefactoringForStartEndComments();
     // apply refactoring
     return _assertSuccessfulRefactoring('''
 main(bool b) {
 // start
   return res(b);
 // end
 }
 
 List res(bool b) {
   if (b) {
+    print(true);
     return <int>[];
   } else {
+    print(false);
     return <String>[];
   }
 }
 ''');
   }
 
   test_statements_return_single() {
     indexTestUnit('''
 main() {
 // start
@@ skipping 126 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();
   }
 }