Add a function to parse metadata into a usable object.

test/util/parse_annotations_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.
-
-import 'dart:io';
-
-import 'package:path/path.dart' as p;
-import 'package:unittest/unittest.dart';
-import 'package:unittest/src/util/dart.dart';
-
-String _sandbox;
-String _path;
-
-void main() {
-  setUp(() {
-    _sandbox = Directory.systemTemp.createTempSync('unittest_').path;
-    _path = p.join(_sandbox, "test.dart");
-  });
-
-  tearDown(() {
-    new Directory(_sandbox).deleteSync(recursive: true);
-  });
-
-  test("with an empty file", () {
-    new File(_path).writeAsStringSync("");
-
-    var annotations = parseAnnotations(_path);
-    expect(annotations, isEmpty);
-  });
-
-  test("before a library tag", () {
-    new File(_path).writeAsStringSync("@Annotation()\nlibrary foo;");
-
-    var annotations = parseAnnotations(_path);
-    expect(annotations, hasLength(1));
-    expect(annotations.first.name.name, equals('Annotation'));
-    expect(annotations.first.arguments.arguments, isEmpty);
-  });
-
-  test("before an import", () {
-    new File(_path).writeAsStringSync("@Annotation()\nimport 'foo';");
-
-    var annotations = parseAnnotations(_path);
-    expect(annotations, hasLength(1));
-    expect(annotations.first.name.name, equals('Annotation'));
-    expect(annotations.first.arguments.arguments, isEmpty);
-  });
-
-  test("multiple annotations", () {
-    new File(_path).writeAsStringSync(
-        "@Annotation1() @Annotation2()\n@Annotation3()\nlibrary foo;");
-
-    var annotations = parseAnnotations(_path);
-    expect(annotations, hasLength(3));
-    expect(annotations[0].name.name, equals('Annotation1'));
-    expect(annotations[0].arguments.arguments, isEmpty);
-    expect(annotations[1].name.name, equals('Annotation2'));
-    expect(annotations[1].arguments.arguments, isEmpty);
-    expect(annotations[2].name.name, equals('Annotation3'));
-    expect(annotations[2].arguments.arguments, isEmpty);
-  });
-
-  test("with no arguments", () {
-    new File(_path).writeAsStringSync("@Annotation\nlibrary foo;");
-
-    var annotations = parseAnnotations(_path);
-    expect(annotations, hasLength(1));
-    expect(annotations.first.name.name, equals('Annotation'));
-    expect(annotations.first.arguments, isNull);
-  });
-
-  test("with positional arguments", () {
-    new File(_path).writeAsStringSync("@Annotation('foo', 12)\nlibrary foo;");
-
-    var annotations = parseAnnotations(_path);
-    expect(annotations, hasLength(1));
-    expect(annotations.first.name.name, equals('Annotation'));
-    var args = annotations.first.arguments.arguments;
-    expect(args, hasLength(2));
-    expect(args[0], new isInstanceOf<StringLiteral>());
-    expect(args[0].stringValue, equals('foo'));
-    expect(args[1], new isInstanceOf<IntegerLiteral>());
-    expect(args[1].value, equals(12));
-  });
-
-  test("with named arguments", () {
-    new File(_path).writeAsStringSync(
-        "@Annotation(name1: 'foo', name2: 12)\nlibrary foo;");
-
-    var annotations = parseAnnotations(_path);
-    expect(annotations, hasLength(1));
-    expect(annotations.first.name.name, equals('Annotation'));
-    var args = annotations.first.arguments.arguments;
-    expect(args, hasLength(2));
-    expect(args[0], new isInstanceOf<NamedExpression>());
-    expect(args[0].expression, new isInstanceOf<StringLiteral>());
-    expect(args[0].expression.stringValue, equals('foo'));
-    expect(args[1], new isInstanceOf<IntegerLiteral>());
-    expect(args[1].expression, new isInstanceOf<IntegerLiteral>());
-    expect(args[1].expression.value, equals(12));
-  });
-
-  test("with a prefix/named constructor", () {
-    new File(_path).writeAsStringSync("@Annotation.name()\nlibrary foo;");
-
-    var annotations = parseAnnotations(_path);
-    expect(annotations, hasLength(1));
-    expect(annotations.first.name, new isInstanceOf<PrefixedIdentifier>());
-    expect(annotations.first.name.prefix.name, equals('Annotation'));
-    expect(annotations.first.name.identifier.name, equals('name'));
-    expect(annotations.first.constructorName, isNull);
-    expect(annotations.first.arguments.arguments, isEmpty);
-  });
-
-  test("with a prefix and named constructor", () {
-    new File(_path).writeAsStringSync(
-        "@prefix.Annotation.name()\nlibrary foo;");
-
-    var annotations = parseAnnotations(_path);
-    expect(annotations, hasLength(1));
-    expect(annotations.first.name, new isInstanceOf<PrefixedIdentifier>());
-    expect(annotations.first.name.prefix.name, equals('prefix'));
-    expect(annotations.first.name.identifier.name, equals('Annotation'));
-    expect(annotations.first.constructorName.name, equals('name'));
-    expect(annotations.first.arguments.arguments, isEmpty);
-  });
-
-  test("annotations after the first directive are ignored", () {
-    new File(_path).writeAsStringSync(
-        "library foo;\n@prefix.Annotation.name()");
-
-    expect(parseAnnotations(_path), isEmpty);
-  });
-
-  group("comments are ignored", () {
-    test("before an annotation", () {
-      new File(_path).writeAsStringSync(
-          "/* comment */@Annotation()\nlibrary foo;");
-
-      var annotations = parseAnnotations(_path);
-      expect(annotations, hasLength(1));
-      expect(annotations.first.name.name, equals('Annotation'));
-      expect(annotations.first.arguments.arguments, isEmpty);
-    });
-
-    test("within an annotation", () {
-      new File(_path).writeAsStringSync(
-          "@Annotation(/* comment */)\nlibrary foo;");
-
-      var annotations = parseAnnotations(_path);
-      expect(annotations, hasLength(1));
-      expect(annotations.first.name.name, equals('Annotation'));
-      expect(annotations.first.arguments.arguments, isEmpty);
-    });
-
-    test("after an annotation", () {
-      new File(_path).writeAsStringSync(
-          "@Annotation()/* comment */\nlibrary foo;");
-
-      var annotations = parseAnnotations(_path);
-      expect(annotations, hasLength(1));
-      expect(annotations.first.name.name, equals('Annotation'));
-      expect(annotations.first.arguments.arguments, isEmpty);
-    });
-
-    test("between annotations", () {
-      new File(_path).writeAsStringSync(
-          "@Annotation1()/* comment */@Annotation2()\nlibrary foo;");
-
-      var annotations = parseAnnotations(_path);
-      expect(annotations, hasLength(2));
-      expect(annotations[0].name.name, equals('Annotation1'));
-      expect(annotations[0].arguments.arguments, isEmpty);
-      expect(annotations[1].name.name, equals('Annotation2'));
-      expect(annotations[1].arguments.arguments, isEmpty);
-    });
-  });
-}