detect flutter and use default analysis options for flutter

pkg/analyzer/test/src/context/builder_test.dart

 // Copyright (c) 2016, 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 analyzer.test.src.context.context_builder_test;
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/command_line/arguments.dart';
 import 'package:analyzer/src/context/builder.dart';
@@ skipping 544 matching lines @@
         '''
 linter:
   rules:
     - mock_lint_rule2
 ''');
     AnalysisOptions options = builder
         .getAnalysisOptions(resourceProvider.convertPath('/root/some/path'));
     _expectEqualOptions(options, expected);
   }
 
+  void test_getAnalysisOptions_default_flutter() {
+    MockLintRule mockLintRule = new MockLintRule('mock_lint_rule');
+    Registry.ruleRegistry.register(mockLintRule);
+    AnalysisOptionsImpl defaultOptions = new AnalysisOptionsImpl();
+    builderOptions.defaultOptions = defaultOptions;
+    AnalysisOptionsImpl expected = new AnalysisOptionsImpl();
+    expected.lint = true;
+    expected.lintRules = <Linter>[mockLintRule];
+    createFile(
+        resourceProvider.convertPath('/some/directory/path/.packages'),
+        '''
+flutter:/pkg/flutter/lib/
+''');
+    createFile(
+        resourceProvider
+            .convertPath('/pkg/flutter/lib/analysis_options_user.yaml'),
+        '''
+linter:
+  rules:
+    - mock_lint_rule
+''');
+    AnalysisOptions options = builder.getAnalysisOptions(
+        resourceProvider.convertPath('/some/directory/path'));
+    _expectEqualOptions(options, expected);
+  }
+
   void test_getAnalysisOptions_default_noOverrides() {
     AnalysisOptionsImpl defaultOptions = new AnalysisOptionsImpl();
     defaultOptions.enableLazyAssignmentOperators = true;
     builderOptions.defaultOptions = defaultOptions;
     AnalysisOptionsImpl expected = new AnalysisOptionsImpl();
     expected.enableLazyAssignmentOperators = true;
     String path = resourceProvider.convertPath('/some/directory/path');
     String filePath =
         pathContext.join(path, AnalysisEngine.ANALYSIS_OPTIONS_YAML_FILE);
     resourceProvider.newFile(
@@ skipping 233 matching lines @@
 class MockLintRule implements LintRule {
   final String _name;
 
   MockLintRule(this._name);
 
   @override
   String get name => _name;
 
   noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 }