Add minimal yaml support to the engine

pkg/analyzer/test/src/task/yaml_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.task.yaml_test;
+
+import 'package:analyzer/src/generated/source.dart';
+import 'package:analyzer/src/task/yaml.dart';
+import 'package:analyzer/task/yaml.dart';
+import 'package:unittest/unittest.dart';
+import 'package:yaml/yaml.dart';
+
+import '../../reflective_tests.dart';
+import '../../utils.dart';
+import '../context/abstract_context.dart';
+
+main() {
+  initializeTestEnvironment();
+  runReflectiveTests(ParseYamlTaskTest);
+}
+
+isInstanceOf isParseYamlTask = new isInstanceOf<ParseYamlTask>();
+
+@reflectiveTest
+class ParseYamlTaskTest extends AbstractContextTest {
+  Source source;
+
+  test_perform() {
+    _performParseTask(r'''
+rules:
+  style_guide:
+    camel_case_types: false
+''');
+    expect(outputs, hasLength(3));
+    YamlDocument document = outputs[YAML_DOCUMENT];
+    expect(document, isNotNull);
+    var value = document.contents.value;
+    expect(value, new isInstanceOf<Map>());
+    expect(value['rules']['style_guide']['camel_case_types'], isFalse);
+    expect(outputs[YAML_ERRORS], hasLength(0));
+    LineInfo lineInfo = outputs[YAML_LINE_INFO];
+    expect(lineInfo, isNotNull);
+    expect(lineInfo.getOffsetOfLine(0), 0);
+    expect(lineInfo.getOffsetOfLine(1), 7);
+    expect(lineInfo.getOffsetOfLine(2), 22);
+    expect(lineInfo.getOffsetOfLine(3), 50);
+  }
+
+  test_perform_doesNotExist() {
+    _performParseTask(null);
+    expect(outputs, hasLength(3));
+    YamlDocument document = outputs[YAML_DOCUMENT];
+    expect(document, isNotNull);
+    expect(document.contents.value, isNull);
+    expect(outputs[YAML_ERRORS], hasLength(1));
+    LineInfo lineInfo = outputs[YAML_LINE_INFO];
+    expect(lineInfo, isNotNull);
+    expect(lineInfo.getOffsetOfLine(0), 0);
+  }
+
+  void _performParseTask(String content) {
+    if (content == null) {
+      source = resourceProvider.getFile('/test.yaml').createSource();
+    } else {
+      source = newSource('/test.yaml', content);
+    }
+    computeResult(source, YAML_DOCUMENT, matcher: isParseYamlTask);
+  }
+}