"flutter drive" command

Runs a test app and a driver test simultaneously, then stops the app.

Usage:

```
flutter drive --target=/path/to/test/app.dart
```

This command will look for `/path/to/test/app_test.dart` by
convention. We will expand into other ways of discovering tests in the
future.

packages/flutter_driver/lib/src/driver.dart

@@ -12,25 +12,12 @@ import 'gesture.dart';
 import 'health.dart';
 import 'message.dart';
 
-/// A function that connects to a Dart VM service given the [url].
-typedef Future<VMServiceClient> VMServiceConnectFunction(String url);
-
-/// Connects to a real Dart VM service using the [VMServiceClient].
-final VMServiceConnectFunction vmServiceClientConnectFunction =
-    VMServiceClient.connect;
-
-/// The connection function used by [FlutterDriver.connect].
-///
-/// Overwrite this function if you require a different method for connecting to
-/// the VM service.
-VMServiceConnectFunction vmServiceConnectFunction =
-    vmServiceClientConnectFunction;
+final Logger _log = new Logger('FlutterDriver');
 
 /// Drives a Flutter Application running in another process.
 class FlutterDriver {
 
   static const String _flutterExtensionMethod = 'ext.flutter_driver';
-  static final Logger _log = new Logger('FlutterDriver');
 
   /// Connects to a Flutter application.
   ///
@@ -174,3 +161,42 @@ class FlutterDriver {
     return null;
   });
 }
+
+/// A function that connects to a Dart VM service given the [url].
+typedef Future<VMServiceClient> VMServiceConnectFunction(String url);
+
+/// The connection function used by [FlutterDriver.connect].
+///
+/// Overwrite this function if you require a custom method for connecting to
+/// the VM service.
+VMServiceConnectFunction vmServiceConnectFunction = _waitAndConnect;
+
+/// Restores [vmServiceConnectFunction] to its default value.
+void restoreVmServiceConnectFunction() {
+  vmServiceConnectFunction = _waitAndConnect;
+}
+
+/// Waits for a real Dart VM service to become available, then connects using
+/// the [VMServiceClient].
+///
+/// Times out after 30 seconds.
+Future<VMServiceClient> _waitAndConnect(String url) async {
+  Stopwatch timer = new Stopwatch();
+  Future<VMServiceClient> attemptConnection() {
+    return VMServiceClient.connect(url)
+      .catchError((e) async {
+        if (timer.elapsed < const Duration(seconds: 30)) {
+          _log.info('Waiting for application to start');
+          await new Future.delayed(const Duration(seconds: 1));
+          return attemptConnection();
+        } else {
+          _log.critical(
+            'Application has not started in 30 seconds. '
+            'Giving up.'
+          );
+          throw e;
+        }
+      });
+  }
+  return attemptConnection();
+}

packages/flutter_driver/test/flutter_driver_test.dart

@@ -40,7 +40,7 @@ main() {
 
     tearDown(() async {
       await logSub.cancel();
-      vmServiceConnectFunction = vmServiceClientConnectFunction;
+      restoreVmServiceConnectFunction();
     });
 
     test('connects to isolate paused at start', () async {

packages/flutter_tools/lib/executable.dart

@@ -19,6 +19,7 @@ import 'src/commands/create.dart';
 import 'src/commands/daemon.dart';
 import 'src/commands/devices.dart';
 import 'src/commands/doctor.dart';
+import 'src/commands/drive.dart';
 import 'src/commands/install.dart';
 import 'src/commands/listen.dart';
 import 'src/commands/logs.dart';
@@ -51,6 +52,7 @@ Future main(List<String> args) async {
     ..addCommand(new DaemonCommand(hideCommand: !verboseHelp))
     ..addCommand(new DevicesCommand())
     ..addCommand(new DoctorCommand())
+    ..addCommand(new DriveCommand())
     ..addCommand(new InstallCommand())
     ..addCommand(new ListenCommand())
     ..addCommand(new LogsCommand())

packages/flutter_tools/lib/src/base/file_system.dart

@@ -2,14 +2,37 @@
 // 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:file/io.dart';
+import 'package:file/sync_io.dart';
 import 'package:path/path.dart' as path;
 
+export 'package:file/io.dart';
+export 'package:file/sync_io.dart';
+
+/// Currently active implmenetation of the file system.
+///
+/// By default it uses local disk-based implementation. Override this in tests
+/// with [MemoryFileSystem].
+FileSystem fs = new LocalFileSystem();
+SyncFileSystem syncFs = new SyncLocalFileSystem();
+
+/// Restores [fs] and [syncFs] to the default local disk-based implementation.
+void restoreFileSystem() {
+  fs = new LocalFileSystem();
+  syncFs = new SyncLocalFileSystem();
+}
+
+void useInMemoryFileSystem() {
+  MemoryFileSystem memFs = new MemoryFileSystem();
+  fs = memFs;
+  syncFs = new SyncMemoryFileSystem(backedBy: memFs.storage);
+}
+
 /// Create the ancestor directories of a file path if they do not already exist.
 void ensureDirectoryExists(String filePath) {
   String dirPath = path.dirname(filePath);
-  if (FileSystemEntity.isDirectorySync(dirPath))
+
+  if (syncFs.type(dirPath) == FileSystemEntityType.DIRECTORY)
     return;
-  new Directory(dirPath).createSync(recursive: true);
+  syncFs.directory(dirPath).create(recursive: true);
 }

packages/flutter_tools/lib/src/commands/apk.dart

@@ -10,7 +10,7 @@ import 'package:path/path.dart' as path;
 import '../android/android_sdk.dart';
 import '../application_package.dart';
 import '../artifacts.dart';
-import '../base/file_system.dart';
+import '../base/file_system.dart' show ensureDirectoryExists;
 import '../base/os.dart';
 import '../base/process.dart';
 import '../build_configuration.dart';

packages/flutter_tools/lib/src/commands/drive.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 'package:path/path.dart' as path;
+import 'package:test/src/executable.dart' as executable;
+
+import '../base/file_system.dart';
+import '../globals.dart';
+import 'run.dart';
+import 'stop.dart';
+
+typedef Future<int> RunAppFunction();
+typedef Future<Null> RunTestsFunction(List<String> testArgs);
+typedef Future<int> StopAppFunction();
+
+/// Runs integration (a.k.a. end-to-end) tests.
+///
+/// An integration test is a program that runs in a separate process from your
+/// Flutter application. It connects to the application and acts like a user,
+/// performing taps, scrolls, reading out widget properties and verifying their
+/// correctness.
+///
+/// This command takes a target Flutter application that you would like to test
+/// as the `--target` option (defaults to `lib/main.dart`). It then looks for a
+/// file with the same name but containing the `_test.dart` suffix. The
+/// `_test.dart` file is expected to be a program that uses
+/// `package:flutter_driver` that exercises your application. Most commonly it
+/// is a test written using `package:test`, but you are free to use something
+/// else.
+///
+/// The app and the test are launched simultaneously. Once the test completes
+/// the application is stopped and the command exits. If all these steps are
+/// successful the exit code will be `0`. Otherwise, you will see a non-zero
+/// exit code.
+class DriveCommand extends RunCommand {
+  final String name = 'drive';
+  final String description = 'Runs Flutter Driver tests for the current project.';
+  final List<String> aliases = <String>['driver'];
+
+  RunAppFunction _runApp;
+  RunTestsFunction _runTests;
+  StopAppFunction _stopApp;
+
+  /// Creates a drive command with custom process management functions.
+  ///
+  /// [runAppFn] starts a Flutter application.
+  ///
+  /// [runTestsFn] runs tests.
+  ///
+  /// [stopAppFn] stops the test app after tests are finished.
+  DriveCommand.custom({
+      RunAppFunction runAppFn,
+      RunTestsFunction runTestsFn,
+      StopAppFunction stopAppFn
+  }) {
+    _runApp = runAppFn ?? super.runInProject;
+    _runTests = runTestsFn ?? executable.main;
+    _stopApp = stopAppFn ?? this.stop;
+  }
+
+  DriveCommand() : this.custom();
+
+  @override
+  Future<int> runInProject() async {
+    String testFile = _getTestFile();
+
+    if (await fs.type(testFile) != FileSystemEntityType.FILE) {
+      printError('Test file not found: $testFile');
+      return 1;
+    }
+
+    int result = await _runApp();
+    if (result != 0) {
+      printError('Application failed to start. Will not run test. Quitting.');
+      return result;
+    }
+
+    try {
+      return await _runTests([testFile])
+        .then((_) => 0)
+        .catchError((error, stackTrace) {
+          printError('ERROR: $error\n$stackTrace');
+          return 1;
+        });
+    } finally {
+      await _stopApp();
+    }
+  }
+
+  Future<int> stop() async {
+    return await stopAll(devices, applicationPackages) ? 0 : 2;
+  }
+
+  String _getTestFile() {
+    String appFile = argResults['target'];
+    String extension = path.extension(appFile);
+    String name = path.withoutExtension(appFile);
+    return '${name}_test$extension';
+  }
+}

packages/flutter_tools/lib/src/commands/run.dart

@@ -164,12 +164,12 @@ Future<int> startApp(
 
   if (stop) {
     printTrace('Running stop command.');
-    stopAll(devices, applicationPackages);
+    await stopAll(devices, applicationPackages);
   }
 
   if (install) {
     printTrace('Running install command.');
-    installApp(devices, applicationPackages);
+    await installApp(devices, applicationPackages);
   }
 
   bool startedSomething = false;

packages/flutter_tools/lib/src/flx.dart

@@ -13,7 +13,7 @@ import 'package:flx/signing.dart';
 import 'package:path/path.dart' as path;
 import 'package:yaml/yaml.dart';
 
-import 'base/file_system.dart';
+import 'base/file_system.dart' show ensureDirectoryExists;
 import 'globals.dart';
 import 'toolchain.dart';
 

packages/flutter_tools/pubspec.yaml

@@ -13,6 +13,7 @@ dependencies:
   args: ^0.13.2+1
   crypto: ^0.9.1
   den_api: ^0.1.0
+  file: ^0.1.0
   mustache4dart: ^1.0.0
   path: ^1.3.0
   pub_semver: ^1.0.0

packages/flutter_tools/test/drive_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 'package:file/file.dart';
+import 'package:flutter_tools/src/commands/drive.dart';
+import 'package:flutter_tools/src/base/file_system.dart';
+import 'package:flutter_tools/src/base/logger.dart';
+import 'package:flutter_tools/src/globals.dart';
+import 'package:test/test.dart';
+
+import 'src/common.dart';
+import 'src/context.dart';
+import 'src/mocks.dart';
+
+main() => defineTests();
+
+defineTests() {
+  group('drive', () {
+    setUp(() {
+      useInMemoryFileSystem();
+    });
+
+    tearDown(() {
+      restoreFileSystem();
+    });
+
+    testUsingContext('returns 1 when test file is not found', () {
+      DriveCommand command = new DriveCommand();
+      applyMocksToCommand(command);
+
+      List<String> args = [
+        'drive',
+        '--target=/some/app/test/e2e.dart',
+      ];
+      return createTestCommandRunner(command).run(args).then((int code) {
+        expect(code, equals(1));
+        BufferLogger buffer = logger;
+        expect(buffer.errorText,
+            contains('Test file not found: /some/app/test/e2e_test.dart'));
+      });
+    });
+
+    testUsingContext('returns 1 when app fails to run', () async {
+      DriveCommand command = new DriveCommand.custom(runAppFn: expectAsync(() {
+        return new Future.value(1);
+      }));
+      applyMocksToCommand(command);
+
+      String testApp = '/some/app/test/e2e.dart';
+      String testFile = '/some/app/test/e2e_test.dart';
+
+      MemoryFileSystem memFs = fs;
+      await memFs.file(testApp).writeAsString('main() {}');
+      await memFs.file(testFile).writeAsString('main() {}');
+
+      List<String> args = [
+        'drive',
+        '--target=$testApp',
+      ];
+      return createTestCommandRunner(command).run(args).then((int code) {
+        expect(code, equals(1));
+        BufferLogger buffer = logger;
+        expect(buffer.errorText, contains(
+          'Application failed to start. Will not run test. Quitting.'
+        ));
+      });
+    });
+
+    testUsingContext('returns 0 when test ends successfully', () async {
+      String testApp = '/some/app/test/e2e.dart';
+      String testFile = '/some/app/test/e2e_test.dart';
+
+      DriveCommand command = new DriveCommand.custom(
+        runAppFn: expectAsync(() {
+          return new Future<int>.value(0);
+        }),
+        runTestsFn: expectAsync((List<String> testArgs) {
+          expect(testArgs, [testFile]);
+          return new Future<Null>.value();
+        }),
+        stopAppFn: expectAsync(() {
+          return new Future<int>.value(0);
+        })
+      );
+      applyMocksToCommand(command);
+
+      MemoryFileSystem memFs = fs;
+      await memFs.file(testApp).writeAsString('main() {}');
+      await memFs.file(testFile).writeAsString('main() {}');
+
+      List<String> args = [
+        'drive',
+        '--target=$testApp',
+      ];
+      return createTestCommandRunner(command).run(args).then((int code) {
+        expect(code, equals(0));
+        BufferLogger buffer = logger;
+        expect(buffer.errorText, isEmpty);
+      });
+    });
+  });
+}