Addtional tests in options.dart to cover 'log' case, and other missed flag tests as they were added.

pkg/analyzer/test/error_test.dart

 // Copyright (c) 2013, 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.
 
 import 'package:unittest/unittest.dart';
 
 import 'utils.dart';
 
 void main() {
   test("a valid Dart file doesn't throw any errors", () {
     expect(
         errorsForFile('void main() => print("Hello, world!");'),
         isNull);
   });
 
+  test("an empty Dart file doesn't throw any errors", () {
+      expect(
+          errorsForFile(''),
+          isNull);
+    });
+
   test("an error on the first line", () {
     expect(errorsForFile('void foo;\n'),
         equals("Error in test.dart: Variables cannot have a type of 'void'\n"));
   });
 
   test("an error on the last line", () {
     expect(errorsForFile('\nvoid foo;'),
         equals("Error in test.dart: Variables cannot have a type of 'void'\n"));
   });
 
@@ skipping 12 matching lines @@
   test("an error at the beginning of a very long line", () {
     expect(errorsForFile('void foo;     $veryLongString'),
         equals("Error in test.dart: Variables cannot have a type of 'void'\n"));
   });
 
   test("an error in the middle of a very long line", () {
     expect(errorsForFile('$veryLongString void foo;$veryLongString'),
         equals("Error in test.dart: Variables cannot have a type of 'void'\n"));
   });
 }