Add support for assets in Fuchsia packages (#14654)

Pull code out of flx.dart:assemble() to make flx.dart:buildAssets
which creates the AssetBundle. This will allow us to create just
this instead of an entire FLX.

packages/flutter_tools/BUILD.gn

@@ -49,6 +49,16 @@ dart_tool("fuchsia_builder") {
   ]
 }
 
+dart_tool("fuchsia_asset_builder") {
+  main_dart = "bin/fuchsia_asset_builder.dart"
+
+  disable_analysis = true
+
+  deps = [
+    ":flutter_tools",
+  ]
+}
+
 dart_tool("fuchsia_tester") {
   main_dart = "bin/fuchsia_tester.dart"
 

packages/flutter_tools/bin/fuchsia_asset_builder.dart

@@ -0,0 +1,90 @@
+// Copyright 2018 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:args/args.dart';
+
+import '../lib/src/asset.dart';
+import '../lib/src/base/file_system.dart' as libfs;
+import '../lib/src/base/io.dart';
+import '../lib/src/base/platform.dart';
+import '../lib/src/cache.dart';
+import '../lib/src/context_runner.dart';
+import '../lib/src/devfs.dart';
+import '../lib/src/flx.dart';
+import '../lib/src/globals.dart';
+
+const String _kOptionPackages = 'packages';
+const String _kOptionWorking = 'working-dir';
+const String _kOptionManifest = 'manifest';
+const String _kOptionAssetManifestOut = 'asset-manifest-out';
+const List<String> _kRequiredOptions = const <String>[
+  _kOptionPackages,
+  _kOptionWorking,
+  _kOptionAssetManifestOut,
+];
+
+Future<Null> main(List<String> args) async {
+  await runInContext(args, run);
+}
+
+Future<Null> writeFile(libfs.File outputFile, DevFSContent content) async {
+  outputFile.createSync(recursive: true);
+  final List<int> data = await content.contentsAsBytes();
+  outputFile.writeAsBytesSync(data);
+  return null;
+}
+
+Future<Null> run(List<String> args) async {
+  final ArgParser parser = new ArgParser()
+    ..addOption(_kOptionPackages, help: 'The .packages file')
+    ..addOption(_kOptionWorking,
+        help: 'The directory where to put temporary files')
+    ..addOption(_kOptionManifest, help: 'The manifest file')
+    ..addOption(_kOptionAssetManifestOut);
+  final ArgResults argResults = parser.parse(args);
+  if (_kRequiredOptions
+      .any((String option) => !argResults.options.contains(option))) {
+    printError('Missing option! All options must be specified.');
+    exit(1);
+  }
+  Cache.flutterRoot = platform.environment['FLUTTER_ROOT'];
+
+  final String workingDir = argResults[_kOptionWorking];
+  final AssetBundle assets = await buildAssets(
+    manifestPath: argResults[_kOptionManifest] ?? defaultManifestPath,
+    workingDirPath: workingDir,
+    packagesPath: argResults[_kOptionPackages],
+    includeDefaultFonts: false,
+  );
+
+  if (assets == null) {
+    print('Unable to find assets.');
+    exit(1);
+  }
+
+  final List<Future<Null>> calls = <Future<Null>>[];
+  assets.entries.forEach((String fileName, DevFSContent content) {
+    final libfs.File outputFile = libfs.fs.file(libfs.fs.path.join(workingDir, fileName));
+    calls.add(writeFile(outputFile, content));
+  });
+  await Future.wait(calls);
+
+  final String outputMan = argResults[_kOptionAssetManifestOut];
+  await writeFuchsiaManifest(assets, argResults[_kOptionWorking], outputMan);
+}
+
+Future<Null> writeFuchsiaManifest(AssetBundle assets, String outputBase, String fileDest) async {
+
+  final libfs.File destFile = libfs.fs.file(fileDest);
+  await destFile.create(recursive: true);
+  final libfs.IOSink outFile = destFile.openWrite();
+
+  for (String path in assets.entries.keys) {
+    outFile.write('data/$path=$outputBase/$path\n');
+  }
+  await outFile.flush();
+  await outFile.close();
+}

packages/flutter_tools/bin/fuchsia_builder.dart

@@ -5,21 +5,16 @@
 import 'dart:async';
 
 import 'package:args/args.dart';
-import 'package:process/process.dart';
 
+import '../lib/src/asset.dart';
 import '../lib/src/base/common.dart';
-import '../lib/src/base/config.dart';
-import '../lib/src/base/context.dart';
 import '../lib/src/base/file_system.dart';
 import '../lib/src/base/io.dart';
-import '../lib/src/base/logger.dart';
-import '../lib/src/base/os.dart';
 import '../lib/src/base/platform.dart';
 import '../lib/src/cache.dart';
-import '../lib/src/disabled_usage.dart';
+import '../lib/src/context_runner.dart';
 import '../lib/src/flx.dart';
 import '../lib/src/globals.dart';
-import '../lib/src/usage.dart';
 
 const String _kOptionPackages = 'packages';
 const String _kOptionOutput = 'output-file';
@@ -40,22 +35,7 @@ const List<String> _kRequiredOptions = const <String>[
 ];
 
 Future<Null> main(List<String> args) async {
-  final AppContext executableContext = new AppContext();
-  executableContext.setVariable(Logger, new StdoutLogger());
-  await executableContext.runInZone(() {
-    // Initialize the context with some defaults.
-    // This list must be kept in sync with lib/executable.dart.
-    context.putIfAbsent(Stdio, () => const Stdio());
-    context.putIfAbsent(Platform, () => const LocalPlatform());
-    context.putIfAbsent(FileSystem, () => const LocalFileSystem());
-    context.putIfAbsent(ProcessManager, () => const LocalProcessManager());
-    context.putIfAbsent(Logger, () => new StdoutLogger());
-    context.putIfAbsent(Cache, () => new Cache());
-    context.putIfAbsent(Config, () => new Config());
-    context.putIfAbsent(OperatingSystemUtils, () => new OperatingSystemUtils());
-    context.putIfAbsent(Usage, () => new DisabledUsage());
-    return run(args);
-  });
+  await runInContext(args, run);
 }
 
 Future<Null> run(List<String> args) async {
@@ -81,15 +61,23 @@ Future<Null> run(List<String> args) async {
   try {
     final String snapshotPath = argResults[_kOptionSnapshot];
     final String dylibPath = argResults[_kOptionDylib];
+    final AssetBundle assets = await buildAssets(
+      manifestPath: argResults[_kOptionManifest] ?? defaultManifestPath,
+      workingDirPath: argResults[_kOptionWorking],
+      packagesPath: argResults[_kOptionPackages],
+      includeDefaultFonts: false,
+    );
+    if (assets == null)
+      throwToolExit('Error building assets for $outputPath', exitCode: 1);
+
     final List<String> dependencies = await assemble(
+      assetBundle: assets,
       outputPath: outputPath,
       snapshotFile: snapshotPath == null ? null : fs.file(snapshotPath),
       dylibFile: dylibPath == null ? null : fs.file(dylibPath),
       workingDirPath: argResults[_kOptionWorking],
-      packagesPath: argResults[_kOptionPackages],
-      manifestPath: argResults[_kOptionManifest] ?? defaultManifestPath,
-      includeDefaultFonts: false,
     );
+
     final String depFilePath = argResults[_kOptionDepFile];
     final int depFileResult = _createDepfile(
         depFilePath,

packages/flutter_tools/lib/src/context_runner.dart

@@ -0,0 +1,39 @@
+// Copyright 2018 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:process/process.dart';
+
+import 'base/config.dart';
+import 'base/context.dart';
+import 'base/file_system.dart';
+import 'base/io.dart';
+import 'base/logger.dart';
+import 'base/os.dart';
+import 'base/platform.dart';
+import 'cache.dart';
+import 'disabled_usage.dart';
+import 'usage.dart';
+
+typedef Future<Null> Runner(List<String> args);
+
+Future<Null> runInContext(List<String> args, Runner runner) {
+  final AppContext executableContext = new AppContext();
+  executableContext.setVariable(Logger, new StdoutLogger());
+  return executableContext.runInZone(() {
+    // Initialize the context with some defaults.
+    // This list must be kept in sync with lib/executable.dart.
+    context.putIfAbsent(Stdio, () => const Stdio());
+    context.putIfAbsent(Platform, () => const LocalPlatform());
+    context.putIfAbsent(FileSystem, () => const LocalFileSystem());
+    context.putIfAbsent(ProcessManager, () => const LocalProcessManager());
+    context.putIfAbsent(Logger, () => new StdoutLogger());
+    context.putIfAbsent(Cache, () => new Cache());
+    context.putIfAbsent(Config, () => new Config());
+    context.putIfAbsent(OperatingSystemUtils, () => new OperatingSystemUtils());
+    context.putIfAbsent(Usage, () => new DisabledUsage());
+    return runner(args);
+  });
+}

packages/flutter_tools/lib/src/flx.dart

@@ -82,34 +82,34 @@ Future<Null> build({
     kernelContent = new DevFSFileContent(fs.file(kernelBinaryFilename));
   }
 
-  return assemble(
+  final AssetBundle assets = await buildAssets(
     manifestPath: manifestPath,
+    workingDirPath: workingDirPath,
+    packagesPath: packagesPath,
+    reportLicensedPackages: reportLicensedPackages,
+  );
+  if (assets == null)
+    throwToolExit('Error building assets for $outputPath', exitCode: 1);
+
+  return assemble(
+    assetBundle: assets,
     kernelContent: kernelContent,
     snapshotFile: snapshotFile,
     outputPath: outputPath,
     privateKeyPath: privateKeyPath,
     workingDirPath: workingDirPath,
-    packagesPath: packagesPath,
-    reportLicensedPackages: reportLicensedPackages
   ).then((_) => null);
 }
 
-Future<List<String>> assemble({
+Future<AssetBundle> buildAssets({
   String manifestPath,
-  DevFSContent kernelContent,
-  File snapshotFile,
-  File dylibFile,
-  String outputPath,
-  String privateKeyPath: defaultPrivateKeyPath,
   String workingDirPath,
   String packagesPath,
   bool includeDefaultFonts: true,
   bool reportLicensedPackages: false
 }) async {
-  outputPath ??= defaultFlxOutputPath;
   workingDirPath ??= getAssetBuildDirectory();
   packagesPath ??= fs.path.absolute(PackageMap.globalPackagesPath);
-  printTrace('Building $outputPath');
 
   // Build the asset bundle.
   final AssetBundle assetBundle = AssetBundleFactory.instance.createBundle();
@@ -121,7 +121,23 @@ Future<List<String>> assemble({
     reportLicensedPackages: reportLicensedPackages
   );
   if (result != 0)
-    throwToolExit('Error building $outputPath: $result', exitCode: result);
+    return null;
+
+  return assetBundle;
+}
+
+Future<List<String>> assemble({
+  AssetBundle assetBundle,
+  DevFSContent kernelContent,
+  File snapshotFile,
+  File dylibFile,
+  String outputPath,
+  String privateKeyPath: defaultPrivateKeyPath,
+  String workingDirPath,
+}) async {
+  outputPath ??= defaultFlxOutputPath;
+  workingDirPath ??= getAssetBuildDirectory();
+  printTrace('Building $outputPath');
 
   final ZipBuilder zipBuilder = new ZipBuilder();