fix(dart/transformer): Correctly handle const object annotations

Previously, annotations which were const objects (as opposed to const
instance creation expressions) were incorrectly output as instance
creation expressions.

Before:
```
const override() // A const instance creation expression
```

After
```
override // A const instance
```

Closes #4481

modules_dart/transform/test/transform/bind_generator/all_tests.dart

@@ -16,49 +16,65 @@ void allTests() {
 
   it('should generate a setter for an `inputs` property in an annotation.',
       () async {
-    var inputPath = 'bind_generator/basic_bind_files/bar.ng_deps.dart';
-    var expected = formatter.format(
-        readFile('bind_generator/basic_bind_files/expected/bar.ng_deps.dart'));
+    var inputPath = 'basic_bind_files/bar.ng_deps.dart';
+    var expected = _readFile('basic_bind_files/expected/bar.ng_deps.dart');
 
-    var output = formatter.format(
-        await createNgSettersAndGetters(reader, new AssetId('a', inputPath)));
+    var output = formatter
+        .format(await createNgSettersAndGetters(reader, _assetId(inputPath)));
     expect(output).toEqual(expected);
   });
 
   it(
       'should generate a single setter when multiple annotations bind to the '
       'same `inputs` property.', () async {
-    var inputPath =
-        'bind_generator/duplicate_bind_name_files/soup.ng_deps.dart';
-    var expected = formatter.format(readFile(
-        'bind_generator/duplicate_bind_name_files/expected/soup.ng_deps.dart'));
+    var inputPath = 'duplicate_bind_name_files/soup.ng_deps.dart';
+    var expected =
+        _readFile('duplicate_bind_name_files/expected/soup.ng_deps.dart');
 
-    var output = formatter.format(
-        await createNgSettersAndGetters(reader, new AssetId('a', inputPath)));
+    var output = formatter
+        .format(await createNgSettersAndGetters(reader, _assetId(inputPath)));
     expect(output).toEqual(expected);
   });
 
   it('should generate setters for queries defined in the class annotation.',
       () async {
-    var inputPath =
-        'bind_generator/queries_class_annotation_files/bar.ng_deps.dart';
-    var expected = formatter.format(readFile(
-        'bind_generator/queries_class_annotation_files/expected/bar.ng_deps.dart'));
+    var inputPath = 'queries_class_annotation_files/bar.ng_deps.dart';
+    var expected =
+        _readFile('queries_class_annotation_files/expected/bar.ng_deps.dart');
 
-    var output = formatter.format(
-        await createNgSettersAndGetters(reader, new AssetId('a', inputPath)));
+    var output = formatter
+        .format(await createNgSettersAndGetters(reader, _assetId(inputPath)));
     expect(output).toEqual(expected);
   });
 
   it('should generate setters for queries defined via prop annotations.',
       () async {
-    var inputPath =
-        'bind_generator/queries_prop_annotations_files/bar.ng_deps.dart';
-    var expected = formatter.format(readFile(
-        'bind_generator/queries_prop_annotations_files/expected/bar.ng_deps.dart'));
+    var inputPath = 'queries_prop_annotations_files/bar.ng_deps.dart';
+    var expected =
+        _readFile('queries_prop_annotations_files/expected/bar.ng_deps.dart');
 
-    var output = formatter.format(
-        await createNgSettersAndGetters(reader, new AssetId('a', inputPath)));
+    var output = formatter
+        .format(await createNgSettersAndGetters(reader, _assetId(inputPath)));
+    expect(output).toEqual(expected);
+  });
+
+  it('should gracefully handle const objects as prop annotations.', () async {
+    var inputPath = 'queries_override_annotation_files/bar.ng_deps.dart';
+    var expected = formatter.format(_readFile(
+        'queries_override_annotation_files/expected/bar.ng_deps.dart'));
+
+    var output = formatter
+        .format(await createNgSettersAndGetters(reader, _assetId(inputPath)));
     expect(output).toEqual(expected);
   });
 }
+
+AssetId _assetId(String path) => new AssetId('a', 'bind_generator/$path');
+
+String _readFile(String path) {
+  var code = readFile('bind_generator/$path');
+  if (path.endsWith('.dart')) {
+    code = formatter.format(code);
+  }
+  return code;
+}

modules_dart/transform/test/transform/bind_generator/queries_override_annotation_files/bar.ng_deps.dart

@@ -0,0 +1,21 @@
+library bar.ng_deps.dart;
+
+import 'bar.dart';
+import 'package:angular2/src/core/metadata.dart';
+
+var _visited = false;
+void initReflector(reflector) {
+  if (_visited) return;
+  _visited = true;
+  reflector
+    ..registerType(
+        ToolTip,
+        new ReflectionInfo(
+            const [const Directive(selector: '[tool-tip]')],
+            const [],
+            () => new ToolTip(),
+            null,
+            const {
+              'queryField': const [override]
+            }));
+}

modules_dart/transform/test/transform/bind_generator/queries_override_annotation_files/expected/bar.ng_deps.dart

@@ -0,0 +1,21 @@
+library bar.ng_deps.dart;
+
+import 'bar.dart';
+import 'package:angular2/src/core/metadata.dart';
+
+var _visited = false;
+void initReflector(reflector) {
+  if (_visited) return;
+  _visited = true;
+  reflector
+    ..registerType(
+        ToolTip,
+        new ReflectionInfo(
+            const [const Directive(selector: '[tool-tip]')],
+            const [],
+            () => new ToolTip(),
+            null,
+            const {
+              'queryField': const [override]
+            }));
+}

modules_dart/transform/test/transform/directive_processor/all_tests.dart

@@ -9,6 +9,7 @@ import 'package:angular2/src/core/linker/interfaces.dart' show LifecycleHooks;
 import 'package:angular2/src/core/dom/html_adapter.dart';
 import 'package:angular2/src/transform/directive_processor/rewriter.dart';
 import 'package:angular2/src/transform/common/annotation_matcher.dart';
+import 'package:angular2/src/transform/common/code/ng_deps_code.dart';
 import 'package:angular2/src/transform/common/asset_reader.dart';
 import 'package:angular2/src/transform/common/logging.dart' as log;
 import 'package:angular2/src/transform/common/model/reflection_info_model.pb.dart';
@@ -210,9 +211,32 @@ void allTests() {
       expect(model.reflectables.first.propertyMetadata.isNotEmpty).toBeTrue();
       expect(model.reflectables.first.propertyMetadata.first.name)
           .toEqual('getVal');
-      expect(model.reflectables.first.propertyMetadata.first.annotations
-              .firstWhere((a) => a.name == 'GetDecorator', orElse: () => null))
-          .toBeNotNull();
+
+      var getDecoratorAnnotation = model
+          .reflectables.first.propertyMetadata.first.annotations
+          .firstWhere((a) => a.name == 'GetDecorator', orElse: () => null);
+      expect(getDecoratorAnnotation).toBeNotNull();
+      expect(getDecoratorAnnotation.isConstObject).toBeFalse();
+    });
+
+    it('should gracefully handle const instances of annotations', () async {
+      // Regression test for i/4481
+      var model = await _testCreateModel('prop_metadata_files/override.dart');
+
+      expect(model.reflectables.first.propertyMetadata).toBeNotNull();
+      expect(model.reflectables.first.propertyMetadata.isNotEmpty).toBeTrue();
+      expect(model.reflectables.first.propertyMetadata.first.name)
+          .toEqual('getVal');
+      var overrideAnnotation = model
+          .reflectables.first.propertyMetadata.first.annotations
+          .firstWhere((a) => a.name == 'override', orElse: () => null);
+
+      expect(overrideAnnotation).toBeNotNull();
+      expect(overrideAnnotation.isConstObject).toBeTrue();
+
+      var buf = new StringBuffer();
+      new NgDepsWriter(buf).writeAnnotationModel(overrideAnnotation);
+      expect(buf.toString()).toEqual('override');
     });
 
     it('should be recorded on setters', () async {

modules_dart/transform/test/transform/directive_processor/prop_metadata_files/override.dart

@@ -0,0 +1,14 @@
+library override;
+
+import 'package:angular2/src/core/metadata.dart';
+
+@Component(selector: '[getters]')
+@View(template: '')
+class FieldComponent implements ValGetter {
+  @override
+  String get getVal => 'a';
+}
+
+abstract class ValGetter {
+  String get getVal;
+}