implement flutter packages get/upgrade command (#5603)

* implement flutter packages get/upgrade command
* alias flutter pub
* refactor findProjectRoot for use by multiple commands

fixes https://github.com/flutter/flutter/issues/4994

packages/flutter_tools/lib/executable.dart

@@ -25,6 +25,7 @@ import 'src/commands/install.dart';
 import 'src/commands/listen.dart';
 import 'src/commands/logs.dart';
 import 'src/commands/setup.dart';
+import 'src/commands/packages.dart';
 import 'src/commands/precache.dart';
 import 'src/commands/refresh.dart';
 import 'src/commands/run.dart';
@@ -68,6 +69,7 @@ Future<Null> main(List<String> args) async {
     ..addCommand(new InstallCommand())
     ..addCommand(new ListenCommand())
     ..addCommand(new LogsCommand())
+    ..addCommand(new PackagesCommand())
     ..addCommand(new PrecacheCommand())
     ..addCommand(new RefreshCommand())
     ..addCommand(new RunCommand())

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

@@ -150,3 +150,19 @@ Future<bool> _isPortAvailable(int port) async {
     return false;
   }
 }
+
+/// Find and return the project root directory relative to the specified
+/// directory or the current working directory if none specified.
+/// Return `null` if the project root could not be found
+/// or if the project root is the flutter repository root.
+String findProjectRoot([String directory]) {
+  const String kProjectRootSentinel = 'pubspec.yaml';
+  directory ??= Directory.current.path;
+  while (true) {
+    if (FileSystemEntity.isFileSync(path.join(directory, kProjectRootSentinel)))
+      return directory;
+    String parent = FileSystemEntity.parentOf(directory);
+    if (directory == parent) return null;
+    directory = parent;
+  }
+}

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

@@ -0,0 +1,72 @@
+// 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 '../base/os.dart';
+import '../dart/pub.dart';
+import '../globals.dart';
+import '../runner/flutter_command.dart';
+
+class PackagesCommand extends FlutterCommand {
+  PackagesCommand() {
+    addSubcommand(new PackagesGetCommand('get', false));
+    addSubcommand(new PackagesGetCommand('upgrade', true));
+  }
+
+  @override
+  final String name = 'packages';
+
+  @override
+  List<String> get aliases => const <String>['pub'];
+
+  @override
+  final String description = 'Commands for managing Flutter packages.';
+
+  @override
+  Future<int> runInProject() => new Future<int>.value(0);
+}
+
+class PackagesGetCommand extends FlutterCommand {
+  @override
+  final String name;
+
+  final bool upgrade;
+
+  PackagesGetCommand(this.name, this.upgrade);
+
+  // TODO: implement description
+  @override
+  String get description =>
+      (upgrade ? 'Upgrade' : 'Get') + ' packages in a Flutter project.';
+
+  @override
+  bool get requiresProjectRoot => false;
+
+  @override
+  String get invocation =>
+      "${runner.executableName} packages $name [<target directory>]";
+
+  @override
+  Future<int> runInProject() async {
+    if (argResults.rest.length > 1) {
+      printStatus('Too many arguments.');
+      printStatus(usage);
+      return 1;
+    }
+
+    String target = findProjectRoot(
+        argResults.rest.length == 1 ? argResults.rest[0] : null);
+    if (target == null) {
+      printStatus('Expected to find project root starting at ' +
+          (argResults.rest.length == 1
+              ? argResults.rest[0]
+              : 'current working directory'));
+      printStatus(usage);
+      return 1;
+    }
+
+    return pubGet(directory: target, upgrade: upgrade, checkLastModified: false);
+  }
+}

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

@@ -3,10 +3,8 @@
 // found in the LICENSE file.
 
 import 'dart:async';
-import 'dart:io';
-
-import 'package:path/path.dart' as path;
 
+import '../base/os.dart';
 import '../base/process.dart';
 import '../dart/pub.dart';
 import '../cache.dart';
@@ -90,20 +88,4 @@ class UpgradeCommand extends FlutterCommand {
       || _gitChangedRegex.hasMatch(line)
       || line == 'Fast-forward';
   }
-
-  /// Find and return the project root directory relative to the specified
-  /// directory or the current working directory if none specified.
-  /// Return `null` if the project root could not be found
-  /// or if the project root is the flutter repository root.
-  static String findProjectRoot([String directory]) {
-    directory ??= Directory.current.path;
-    while (true) {
-      if (FileSystemEntity.isFileSync(path.join(directory, 'pubspec.yaml')))
-        return directory;
-      String parent = FileSystemEntity.parentOf(directory);
-      if (directory == parent)
-        return null;
-      directory = parent;
-    }
-  }
 }

packages/flutter_tools/test/all.dart

@@ -30,6 +30,7 @@ import 'install_test.dart' as install_test;
 import 'listen_test.dart' as listen_test;
 import 'logs_test.dart' as logs_test;
 import 'os_utils_test.dart' as os_utils_test;
+import 'packages_test.dart' as packages_test;
 import 'protocol_discovery_test.dart' as protocol_discovery_test;
 import 'run_test.dart' as run_test;
 import 'stop_test.dart' as stop_test;
@@ -62,6 +63,7 @@ void main() {
   listen_test.main();
   logs_test.main();
   os_utils_test.main();
+  packages_test.main();
   protocol_discovery_test.main();
   run_test.main();
   stop_test.main();

packages/flutter_tools/test/packages_test.dart

@@ -0,0 +1,63 @@
+// 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:io';
+
+import 'package:args/command_runner.dart';
+import 'package:flutter_tools/src/commands/create.dart';
+import 'package:flutter_tools/src/commands/packages.dart';
+import 'package:test/test.dart';
+
+import 'src/common.dart';
+import 'src/context.dart';
+
+void main() {
+  group('packages', () {
+    Directory temp;
+
+    setUp(() {
+      temp = Directory.systemTemp.createTempSync('flutter_tools');
+    });
+
+    tearDown(() {
+      temp.deleteSync(recursive: true);
+    });
+
+    Future<Null> createProject() async {
+      CreateCommand command = new CreateCommand();
+      CommandRunner runner = createTestCommandRunner(command);
+
+      int code = await runner.run(<String>['create', '--no-pub', temp.path]);
+      expect(code, 0);
+    }
+
+    Future<Null> runCommand(String verb) async {
+      await createProject();
+
+      PackagesCommand command = new PackagesCommand();
+      CommandRunner runner = createTestCommandRunner(command);
+
+      int code = await runner.run(<String>['packages', verb, temp.path]);
+      expect(code, 0);
+    }
+
+    void expectExists(String relPath) {
+      expect(FileSystemEntity.isFileSync('${temp.path}/$relPath'), true);
+    }
+
+    // Verify that we create a project that is well-formed.
+    testUsingContext('get', () async {
+      await runCommand('get');
+      expectExists('lib/main.dart');
+      expectExists('.packages');
+    });
+
+    testUsingContext('upgrade', () async {
+      await runCommand('upgrade');
+      expectExists('lib/main.dart');
+      expectExists('.packages');
+    });
+  });
+}

packages/flutter_tools/test/upgrade_test.dart

@@ -6,6 +6,7 @@ import 'dart:async';
 import 'dart:io';
 
 import 'package:args/command_runner.dart';
+import 'package:flutter_tools/src/base/os.dart';
 import 'package:flutter_tools/src/cache.dart';
 import 'package:flutter_tools/src/commands/create.dart';
 import 'package:flutter_tools/src/commands/upgrade.dart';
@@ -57,18 +58,18 @@ void main() {
         await createProject();
 
         String proj = temp.path;
-        expect(UpgradeCommand.findProjectRoot(proj), proj);
-        expect(UpgradeCommand.findProjectRoot(path.join(proj, 'lib')), proj);
+        expect(findProjectRoot(proj), proj);
+        expect(findProjectRoot(path.join(proj, 'lib')), proj);
 
         String hello = path.join(Cache.flutterRoot, 'examples', 'hello_world');
-        expect(UpgradeCommand.findProjectRoot(hello), hello);
-        expect(UpgradeCommand.findProjectRoot(path.join(hello, 'lib')), hello);
+        expect(findProjectRoot(hello), hello);
+        expect(findProjectRoot(path.join(hello, 'lib')), hello);
       });
 
       testUsingContext('outside project', () async {
         await createProject();
-        expect(UpgradeCommand.findProjectRoot(temp.parent.path), null);
-        expect(UpgradeCommand.findProjectRoot(Cache.flutterRoot), null);
+        expect(findProjectRoot(temp.parent.path), null);
+        expect(findProjectRoot(Cache.flutterRoot), null);
       });
     });
   });