Add firefox support.

See #31

R=kevmoo@google.com

Review URL: https://codereview.chromium.org//1070313002

CHANGELOG.md

@@ -4,6 +4,8 @@
   of concurrent test suites will be run equal to half the machine's processors;
   this can be controlled with the `--concurrency` flag.
 
+* Add support for running tests on Firefox.
+
 ### 0.12.0-beta.5
 
 * Add a `--pub-serve` flag that runs tests against a `pub serve` instance.

lib/src/backend/test_platform.dart

@@ -11,14 +11,19 @@ class TestPlatform {
   // variable tests in test/backend/platform_selector/evaluate_test.
 
   /// The command-line Dart VM.
-  static const vm = const TestPlatform._("VM", "vm", isDartVm: true);
+  static const TestPlatform vm =
+      const TestPlatform._("VM", "vm", isDartVm: true);
 
   /// Google Chrome.
-  static const chrome = const TestPlatform._("Chrome", "chrome",
+  static const TestPlatform chrome = const TestPlatform._("Chrome", "chrome",
       isBrowser: true, isJS: true, isBlink: true);
 
+  /// Mozilla Firefox.
+  static const TestPlatform firefox = const TestPlatform._("Firefox", "firefox",
+      isBrowser: true, isJS: true);
+
   /// A list of all instances of [TestPlatform].
-  static const all = const [vm, chrome];
+  static const List<TestPlatform> all = const [vm, chrome, firefox];
 
   /// Finds a platform by its identifier string.
   ///

lib/src/runner/browser/browser.dart

@@ -0,0 +1,29 @@
+// 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.
+
+library test.runner.browser.browser;
+
+import 'dart:async';
+
+/// An interface for running browser instances.
+///
+/// This is intentionally coarse-grained: browsers are controlled primary from
+/// inside a single tab. Thus this interface only provides support for closing
+/// the browser and seeing if it closes itself.
+///
+/// Any errors starting or running the browser process are reported through
+/// [onExit].
+abstract class Browser {
+  /// A future that completes when the browser exits.
+  ///
+  /// If there's a problem starting or running the browser, this will complete
+  /// with an error.
+  Future get onExit;
+
+  /// Kills the browser process.
+  ///
+  /// Returns the same [Future] as [onExit], except that it won't emit
+  /// exceptions.
+  Future close();
+}

lib/src/runner/browser/chrome.dart

@@ -10,6 +10,7 @@ import 'dart:io';
 import 'package:path/path.dart' as p;
 
 import '../../util/io.dart';
+import 'browser.dart';
 
 // TODO(nweiz): move this into its own package?
 // TODO(nweiz): support other browsers.
@@ -20,7 +21,7 @@ import '../../util/io.dart';
 /// constructed, and is killed when [close] is called.
 ///
 /// Any errors starting or running the process are reported through [onExit].
-class Chrome {
+class Chrome implements Browser {
   /// The underlying process.
   Process _process;
 
@@ -30,10 +31,6 @@ class Chrome {
   /// well-isolated.
   String _dir;
 
-  /// A future that completes when the browser exits.
-  ///
-  /// If there's a problem starting or running the browser, this will complete
-  /// with an error.
   Future get onExit => _onExitCompleter.future;
   final _onExitCompleter = new Completer();
 
@@ -80,10 +77,6 @@ class Chrome {
         .catchError(_onExitCompleter.completeError);
   }
 
-  /// Kills the browser process.
-  ///
-  /// Returns the same [Future] as [onExit], except that it won't emit
-  /// exceptions.
   Future close() {
     _onProcessStarted.then((_) => _process.kill());
 

lib/src/runner/browser/firefox.dart

@@ -0,0 +1,115 @@
+// 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.
+
+library test.runner.browser.firefox;
+
+import 'dart:async';
+import 'dart:io';
+
+import 'package:path/path.dart' as p;
+
+import '../../util/io.dart';
+import 'browser.dart';
+
+final _preferences = '''
+user_pref("browser.shell.checkDefaultBrowser", false);
+user_pref("dom.disable_open_during_load", false);
+user_pref("dom.max_script_run_time", 0);
+''';
+
+/// A class for running an instance of Firefox.
+///
+/// Most of the communication with the browser is expected to happen via HTTP,
+/// so this exposes a bare-bones API. The browser starts as soon as the class is
+/// constructed, and is killed when [close] is called.
+///
+/// Any errors starting or running the process are reported through [onExit].
+class Firefox implements Browser {
+  /// The underlying process.
+  Process _process;
+
+  /// The temporary directory used as the browser's user data dir.
+  ///
+  /// A new data dir is created for each run to ensure that they're
+  /// well-isolated.
+  String _dir;
+
+  Future get onExit => _onExitCompleter.future;
+  final _onExitCompleter = new Completer();
+
+  /// A future that completes when the browser process has started.
+  ///
+  /// This is used to ensure that [close] works regardless of when it's called.
+  Future get _onProcessStarted => _onProcessStartedCompleter.future;
+  final _onProcessStartedCompleter = new Completer();
+
+  /// Starts a new instance of Firefox open to the given [url], which may be a
+  /// [Uri] or a [String].
+  ///
+  /// If [executable] is passed, it's used as the Firefox executable. Otherwise
+  /// the default executable name for the current OS will be used.
+  Firefox(url, {String executable}) {
+    if (executable == null) executable = _defaultExecutable();
+
+    // Don't return a Future here because there's no need for the caller to wait
+    // for the process to actually start. They should just wait for the HTTP
+    // request instead.
+    withTempDir((dir) {
+      _dir = dir;
+
+      new File(p.join(dir, 'prefs.js')).writeAsStringSync(_preferences);
+
+      return Process.start(executable, [
+        "--profile",
+        "$_dir",
+        url.toString(),
+        "--no-remote"
+      ]).then((process) {
+        _process = process;
+        _onProcessStartedCompleter.complete();
+
+        // TODO(nweiz): the browser's standard output is almost always useless
+        // noise, but we should allow the user to opt in to seeing it.
+        return _process.exitCode;
+      });
+    }).then((exitCode) {
+      if (exitCode != 0) throw "Firefox failed with exit code $exitCode.";
+    }).then(_onExitCompleter.complete)
+        .catchError(_onExitCompleter.completeError);
+  }
+
+  Future close() {
+    _onProcessStarted.then((_) => _process.kill());
+
+    // Swallow exceptions. The user should explicitly use [onExit] for these.
+    return onExit.catchError((_) {});
+  }
+
+  /// Return the default executable for the current operating system.
+  String _defaultExecutable() {
+    if (Platform.isMacOS) {
+      return '/Applications/Firefox.app/Contents/MacOS/firefox-bin';
+    }
+    if (!Platform.isWindows) return 'firefox';
+
+    // Firefox could be installed in several places on Windows. The only way to
+    // find it is to check.
+    var prefixes = [
+      Platform.environment['PROGRAMFILES'],
+      Platform.environment['PROGRAMFILES(X86)']
+    ];
+    var suffix = r'Mozilla Firefox\firefox.exe';
+
+    for (var prefix in prefixes) {
+      if (prefix == null) continue;
+
+      var path = p.join(prefix, suffix);
+      if (new File(p.join(prefix, suffix)).existsSync()) return path;
+    }
+
+    // Fall back on looking it up on the path. This probably won't work, but at
+    // least it will fail with a useful error message.
+    return "firefox.exe";
+  }
+}