Make it possible to run tests outside the Flutter repo

This patch still requires a locally built engine. I'll remove the need for a
locally built engine in a future patch.

Fixes #278

packages/flutter_tools/lib/src/artifacts.dart

@@ -83,15 +83,11 @@ class Artifact {
     return null;
   }
 
-  String getUrl(String revision) {
-    return _getCloudStorageBaseUrl(
-      platform: platform,
-      revision: revision
-    ) + fileName;
-  }
-
   // Whether the artifact needs to be marked as executable on disk.
-  bool get executable => type == ArtifactType.snapshot;
+  bool get executable {
+    return type == ArtifactType.snapshot ||
+      (type == ArtifactType.shell && targetPlatform == TargetPlatform.linux);
+  }
 }
 
 class ArtifactStore {
@@ -102,6 +98,12 @@ class ArtifactStore {
       type: ArtifactType.shell,
       targetPlatform: TargetPlatform.android
     ),
+    const Artifact._(
+      name: 'Sky Shell',
+      fileName: 'sky_shell',
+      type: ArtifactType.shell,
+      targetPlatform: TargetPlatform.linux
+    ),
     const Artifact._(
       name: 'Sky Snapshot',
       fileName: 'sky_snapshot',

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

@@ -19,6 +19,12 @@ abstract class FlutterCommand extends Command {
   /// Whether this command needs to be run from the root of a project.
   bool get requiresProjectRoot => true;
 
+  String get projectRootValidationErrorMessage {
+    return 'Error: No pubspec.yaml file found.\n'
+      'This command should be run from the root of your Flutter project. Do not run\n'
+      'this command from the root of your git clone of Flutter.';
+  }
+
   List<BuildConfiguration> get buildConfigurations => runner.buildConfigurations;
 
   Future downloadApplicationPackages() async {
@@ -48,17 +54,17 @@ abstract class FlutterCommand extends Command {
   }
 
   Future<int> run() async {
-    if (requiresProjectRoot) {
+    if (requiresProjectRoot && !validateProjectRoot())
-      if (!FileSystemEntity.isFileSync('pubspec.yaml')) {
-        stderr.writeln('Error: No pubspec.yaml file found. '
-            'This command should be run from the root of your Flutter project. '
-            'Do not run this command from the root of your git clone '
-            'of Flutter.');
       return 1;
-      }
+    return await runInProject();
   }
 
-    return await runInProject();
+  bool validateProjectRoot() {
+    if (!FileSystemEntity.isFileSync('pubspec.yaml')) {
+      stderr.writeln(projectRootValidationErrorMessage);
+      return false;
+    }
+    return true;
   }
 
   Future<int> runInProject();

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

@@ -22,6 +22,12 @@ class TestCommand extends FlutterCommand {
 
   bool get requiresProjectRoot => false;
 
+  String get projectRootValidationErrorMessage {
+    return 'Error: No pubspec.yaml file found.\n'
+      'If you wish to run the tests in the flutter repo, pass --flutter-repo before\n'
+      'any test paths. Otherwise, run this command from the root of your project.';
+  }
+
   String getShellPath(TargetPlatform platform, String buildPath) {
     switch (platform) {
       case TargetPlatform.linux:
@@ -33,34 +39,59 @@ class TestCommand extends FlutterCommand {
     }
   }
 
+  TestCommand() {
+    argParser.addFlag('flutter-repo', help: 'Run tests from the Flutter repository instead of the current directory.', defaultsTo: false);
+  }
+
+  Iterable<String> _findTests(Directory directory) {
+    return directory.listSync(recursive: true, followLinks: false)
+                    .where((FileSystemEntity entity) => entity.path.endsWith('_test.dart') && FileSystemEntity.isFileSync(entity.path))
+                    .map((FileSystemEntity entity) => path.absolute(entity.path));
+  }
+
+  Directory get _flutterUnitTestDir {
+    return new Directory(path.join(ArtifactStore.flutterRoot, 'packages', 'unit', 'test'));
+  }
+
+  Future<int> _runTests(List<String> testArgs, Directory testDirectory) async {
+    Directory currentDirectory = Directory.current;
+    try {
+      Directory.current = testDirectory;
+      return await executable.main(testArgs);
+    } finally {
+      Directory.current = currentDirectory;
+    }
+  }
+
   @override
   Future<int> runInProject() async {
-    List<String> testArgs = argResults.rest.toList();
+    List<String> testArgs = argResults.rest.map((String testPath) => path.absolute(testPath)).toList();
-    Directory flutterDir = new Directory(path.join(ArtifactStore.flutterRoot, 'packages/unit')); // see https://github.com/flutter/flutter/issues/50
+
-    Directory testDir = new Directory(path.join(flutterDir.path, 'test'));
+    final bool runFlutterTests = argResults['flutter-repo'];
-    if (testArgs.isEmpty) {
+    if (!runFlutterTests && !validateProjectRoot())
-      testArgs.addAll(testDir.listSync(recursive: true, followLinks: false)
+      return 1;
-                             .where((FileSystemEntity entity) => entity.path.endsWith('_test.dart') && FileSystemEntity.isFileSync(entity.path))
+
-                             .map((FileSystemEntity entity) => path.absolute(entity.path)));
+    Directory testDir = runFlutterTests ? _flutterUnitTestDir : Directory.current;
-    }
+
+    if (testArgs.isEmpty)
+      testArgs.addAll(_findTests(testDir));
+
     testArgs.insert(0, '--');
     if (Platform.environment['TERM'] == 'dumb')
       testArgs.insert(0, '--no-color');
     List<BuildConfiguration> configs = buildConfigurations;
     bool foundOne = false;
-    String currentDirectory = Directory.current.path;
-    Directory.current = flutterDir.path;
     loader.installHook();
     for (BuildConfiguration config in configs) {
       if (!config.testable)
         continue;
       foundOne = true;
-      loader.shellPath = path.join(currentDirectory, getShellPath(config.targetPlatform, config.buildDir));
+      loader.shellPath = path.join(Directory.current.path, getShellPath(config.targetPlatform, config.buildDir));
       if (!FileSystemEntity.isFileSync(loader.shellPath)) {
           _logging.severe('Cannot find Flutter shell at ${loader.shellPath}');
         return 1;
       }
-      await executable.main(testArgs);
+      await _runTests(testArgs, testDir);
       if (exitCode != 0)
         return exitCode;
     }

travis/test.sh

@@ -5,7 +5,7 @@ set -ex
 ./bin/flutter analyze --flutter-repo --no-current-directory --no-current-package --congratulate
 
 # flutter package tests
-./bin/flutter test --engine-src-path bin/cache/travis
+./bin/flutter test --flutter-repo --engine-src-path bin/cache/travis
 
 (cd packages/cassowary; pub run test -j1)
 # (cd packages/flutter_sprites; ) # No tests to run.