Dart: Adds tests of a couple Dart examples.

examples/dart/hello_world/hello/test/hello_test.dart

+// Copyright 2016 The Chromium Authors. 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:async';
+import 'dart:convert';
+import 'dart:io';
+
+import "package:args/args.dart";
+import "package:path/path.dart" as path;
+import "package:test/test.dart";
+
+void main(List<String> args) {
+  final ArgParser parser = new ArgParser();
+  parser.addOption('mojo-shell',
+      help: 'Path to the Mojo shell.');
+  final ArgResults results = parser.parse(args);
+  final String shellPath = results['mojo-shell'];
+  final List<String> devtoolsFlags = results.rest;
+
+  test("Hello, .mojo!", () async {
+    final String mojoUrl = 'http://core.mojoapps.io/dart_hello.mojo';
+    final List<String> args = new List.from(devtoolsFlags)..add(mojoUrl);
+    final ProcessResult result = await Process.run(shellPath, args);
+    expect(result.exitCode, equals(0));
+    expect(result.stdout.contains('Hello'), isTrue);
+    expect(result.stdout.contains('World'), isTrue);
+  });
+
+  test("Hello, .dart!", () async {
+    final HttpServer server = await HttpServer.bind('127.0.0.1', 0);
+    final String scriptOrigin = path.normalize(
+        path.join(path.dirname(Platform.script.path), '..', '..'));
+    final String packageOrigin = path.normalize(
+        path.join(path.fromUri(Platform.packageRoot), '..'));
+
+    server.listen((HttpRequest request) async {
+      final String requestPath = request.uri.toFilePath();
+
+      String origin;
+      if (requestPath.startsWith('/packages')) {
+        origin = packageOrigin;
+      } else {
+        origin = scriptOrigin;
+      }
+
+      final String filePath =
+          path.join(origin, path.relative(requestPath, from: '/'));;
+      final File file = new File(filePath);
+      if (await file.exists()) {
+        try {
+          await file.openRead().pipe(request.response);
+        } catch (e) {
+          print(e);
+        }
+      } else {
+        request.response.statusCode = HttpStatus.NOT_FOUND;
+        request.response.close();
+      }
+    });
+
+    final String dartUrl =
+        'http://127.0.0.1:${server.port}/hello/lib/main.dart';
+
+    final List<String> args = new List.from(devtoolsFlags)..add(dartUrl);
+    final ProcessResult result = await Process.run(shellPath, args);
+    expect(result.exitCode, equals(0));
+    expect(result.stdout.contains('Hello'), isTrue);
+    expect(result.stdout.contains('World'), isTrue);
+    server.close();
+  });
+}