Improved YAML doc exception handling.

pkg/analyzer/test/source/analysis_options_provider_test.dart

 // Copyright (c) 2015, 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.source.analysis_options_provider;
 
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/source/analysis_options_provider.dart';
 import 'package:unittest/unittest.dart';
 import 'package:yaml/yaml.dart';
@@ skipping 57 matching lines @@
       try {
         Map<String, YamlNode> options =
             optionsProvider.getOptions(resourceProvider.getFolder('/'));
         expect(options, isNotNull);
       } catch (e) {
         exceptionCaught = true;
       }
       expect(exceptionCaught, isTrue);
     });
   });
+  group('AnalysisOptionsProvider', () {
+    test('test_bad_yaml', () {
+      var src = '''
+      analyzer:
+  exclude:
+    - test/data/*
+  error:
+    invalid_assignment: ignore
+    unused_local_variable: # <=== bang
+linter:
+  rules:
+    - camel_case_types
+''';
+
+      var optionsProvider = new AnalysisOptionsProvider();
+      expect(() => optionsProvider.getOptionsFromString(src),
+          throwsA(new isInstanceOf<OptionsFormatException>()));
+    });
+  });
 }
 
 MemoryResourceProvider resourceProvider;
 
-buildResourceProvider({bool emptyAnalysisOptions : false,
-                       bool badAnalysisOptions : false}) {
+buildResourceProvider(
+    {bool emptyAnalysisOptions: false, bool badAnalysisOptions: false}) {
   resourceProvider = new MemoryResourceProvider();
   resourceProvider.newFolder('/empty');
   resourceProvider.newFolder('/tmp');
   if (badAnalysisOptions) {
     resourceProvider.newFile('/.analysis_options', r''':''');
   } else if (emptyAnalysisOptions) {
     resourceProvider.newFile('/.analysis_options', r'''#empty''');
   } else {
     resourceProvider.newFile(
-      '/.analysis_options',
-      r'''
+        '/.analysis_options',
+        r'''
 analyzer:
   ignore:
     - ignoreme.dart
     - 'sdk_ext/**'
 ''');
   }
 }
 
 clearResourceProvider() {
   resourceProvider = null;
 }
 
 emptyResourceProvider() {
   resourceProvider = new MemoryResourceProvider();
 }