Make flutter run_mojo imply flutter build

This makes run_mojo more similar to flutter start.

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

@@ -9,6 +9,7 @@ import 'package:logging/logging.dart';
 import 'package:path/path.dart' as path;
 
 import '../build_configuration.dart';
+import '../file_system.dart';
 import 'build.dart';
 import 'flutter_command.dart';
 import 'start.dart';
@@ -20,13 +21,6 @@ const String _kKeystorePassword = "chromium";
 
 final Logger _logging = new Logger('flutter_tools.apk');
 
-/// Create the ancestor directories of a file path if they do not already exist.
-void _ensureDirectoryExists(String filePath) {
-  Directory dir = new Directory(path.dirname(filePath));
-  if (!dir.existsSync())
-    dir.createSync(recursive: true);
-}
-
 /// Copies files into a new directory structure.
 class _AssetBuilder {
   final Directory outDir;
@@ -40,7 +34,7 @@ class _AssetBuilder {
 
   void add(File asset, String relativePath) {
     String destPath = path.join(_assetDir.path, relativePath);
-    _ensureDirectoryExists(destPath);
+    ensureDirectoryExists(destPath);
     asset.copySync(destPath);
   }
 
@@ -147,7 +141,7 @@ class ApkCommand extends FlutterCommand {
     }
 
     Directory tempDir = Directory.systemTemp.createTempSync('flutter_tools');
-    try {      
+    try {
       _AssetBuilder assetBuilder = new _AssetBuilder(tempDir, 'assets');
       assetBuilder.add(icuData, 'icudtl.dat');
       assetBuilder.add(new File(flxPath), 'app.flx');
@@ -163,7 +157,7 @@ class ApkCommand extends FlutterCommand {
       builder.sign(keystore, _kKeystorePassword, _kKeystoreKeyName, unalignedApk);
 
       File finalApk = new File(argResults['output-file']);
-      _ensureDirectoryExists(finalApk.path);
+      ensureDirectoryExists(finalApk.path);
       builder.align(unalignedApk, finalApk);
 
       return 0;
@@ -203,10 +197,10 @@ class ApkCommand extends FlutterCommand {
       builder.inheritFromParent(this);
       int result;
       await builder.buildInTempDir(
-          mainPath: mainPath,
-          onBundleAvailable: (String localBundlePath) {
-        result = _buildApk(config, localBundlePath);
-      }
+        mainPath: mainPath,
+        onBundleAvailable: (String localBundlePath) {
+          result = _buildApk(config, localBundlePath);
+        }
       );
 
       return result;

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

@@ -12,6 +12,7 @@ import 'package:flx/signing.dart';
 import 'package:path/path.dart' as path;
 import 'package:yaml/yaml.dart';
 
+import '../file_system.dart';
 import '../toolchain.dart';
 import 'flutter_command.dart';
 
@@ -109,8 +110,8 @@ ArchiveFile _createSnapshotFile(String snapshotPath) {
 const String _kDefaultAssetBase = 'packages/material_design_icons/icons';
 const String _kDefaultMainPath = 'lib/main.dart';
 const String _kDefaultManifestPath = 'flutter.yaml';
-const String _kDefaultOutputPath = 'app.flx';
-const String _kDefaultSnapshotPath = 'snapshot_blob.bin';
+const String _kDefaultOutputPath = 'build/app.flx';
+const String _kDefaultSnapshotPath = 'build/snapshot_blob.bin';
 const String _kDefaultPrivateKeyPath = 'privatekey.der';
 
 class BuildCommand extends FlutterCommand {
@@ -186,6 +187,8 @@ class BuildCommand extends FlutterCommand {
     Archive archive = new Archive();
 
     if (!precompiledSnapshot) {
+      ensureDirectoryExists(snapshotPath);
+
       // In a precompiled snapshot, the instruction buffer contains script
       // content equivalents
       int result = await toolchain.compiler.compile(mainPath: mainPath, snapshotPath: snapshotPath);
@@ -208,6 +211,7 @@ class BuildCommand extends FlutterCommand {
 
     AsymmetricKeyPair keyPair = keyPairFromPrivateKeyFileSync(privateKeyPath);
     Uint8List zipBytes = new Uint8List.fromList(new ZipEncoder().encode(archive));
+    ensureDirectoryExists(outputPath);
     Bundle bundle = new Bundle.fromContent(
       path: outputPath,
       manifest: manifestDescriptor,

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

@@ -11,7 +11,11 @@ import 'package:path/path.dart' as path;
 import '../artifacts.dart';
 import '../build_configuration.dart';
 import '../process.dart';
+import 'build.dart';
 import 'flutter_command.dart';
+import 'start.dart';
+
+const String _kDefaultBundlePath = 'build/app.flx';
 
 final Logger _logging = new Logger('flutter_tools.run_mojo');
 
@@ -25,7 +29,11 @@ class RunMojoCommand extends FlutterCommand {
     argParser.addFlag('mojo-debug', negatable: false, help: 'Use Debug build of mojo');
     argParser.addFlag('mojo-release', negatable: false, help: 'Use Release build of mojo (default)');
 
-    argParser.addOption('app', defaultsTo: 'app.flx');
+    argParser.addOption('target',
+        defaultsTo: '',
+        abbr: 't',
+        help: 'Target app path or filename to start.');
+    argParser.addOption('app', help: 'Run this Flutter app instead of building the target.');
     argParser.addOption('mojo-path', help: 'Path to directory containing mojo_shell and services.');
     argParser.addOption('devtools-path', help: 'Path to mojo devtools\' mojo_run command.');
   }
@@ -72,7 +80,7 @@ class RunMojoCommand extends FlutterCommand {
     return result;
   }
 
-  Future<List<String>> _getShellConfig() async {
+  Future<List<String>> _getShellConfig(String bundlePath) async {
     List<String> args = <String>[];
 
     final bool useDevtools = _useDevtools();
@@ -82,7 +90,7 @@ class RunMojoCommand extends FlutterCommand {
     if (argResults['android']) {
       args.add('--android');
       final String cloudStorageBaseUrl = ArtifactStore.getCloudStorageBaseUrl('shell', 'android-arm');
-      final String appPath = _makePathAbsolute(argResults['app']);
+      final String appPath = _makePathAbsolute(bundlePath);
       final String appName = path.basename(appPath);
       final String appDir = path.dirname(appPath);
       args.add('http://app/$appName');
@@ -90,7 +98,7 @@ class RunMojoCommand extends FlutterCommand {
       args.add('--map-origin=http://flutter/=$cloudStorageBaseUrl');
       args.add('--url-mappings=mojo:flutter=http://flutter/flutter.mojo');
     } else {
-      final String appPath = _makePathAbsolute(argResults['app']);
+      final String appPath = _makePathAbsolute(bundlePath);
       String flutterPath;
       BuildConfiguration config = _getCurrentHostConfig();
       if (config == null || config.type == BuildType.prebuilt) {
@@ -136,7 +144,21 @@ class RunMojoCommand extends FlutterCommand {
       return 1;
     }
 
-    return await runCommandAndStreamOutput(await _getShellConfig());
-  }
+    await downloadToolchain();
+
+    String bundlePath = argResults['app'];
+    if (bundlePath == null) {
+      bundlePath = _kDefaultBundlePath;
+
+      String mainPath = StartCommand.findMainDartFile(argResults['target']);
 
+      BuildCommand builder = new BuildCommand();
+      builder.inheritFromParent(this);
+      int result = await builder.build(mainPath: mainPath, outputPath: bundlePath);
+      if (result != 0)
+        return result;
+    }
+
+    return await runCommandAndStreamOutput(await _getShellConfig(bundlePath));
+  }
 }

packages/flutter_tools/lib/src/file_system.dart

+// Copyright 2015 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:io';
+
+import 'package:path/path.dart' as path;
+
+/// 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))
+    return;
+  new Directory(dirPath).createSync(recursive: true);
+}