Adding support for android app bundle - Issue #17829 (#24440)

* adding support for android app bundle.

* removing the debug statement.

* fixing formatting and code review changes.

* Revert "fixing formatting and code review changes."

This reverts commit 2041d45.

* Fixing code formatting issues.

* updating review comments fixing comments and spacing.

* changing and to & to rerun the CI and tests.

* updating the comment to re-run the test

updating the comment to re-run the test

* fixing the formatting.

* updating comments to re-trigger build

updating comments to re-trigger build

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

@@ -44,5 +44,6 @@ Future<void> buildApk({
     project: project,
     buildInfo: buildInfo,
     target: target,
+    isBuildingBundle: false
   );
 }

packages/flutter_tools/lib/src/android/app_bundle.dart

@@ -0,0 +1,49 @@
+// 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:async';
+
+import 'package:meta/meta.dart';
+
+import '../base/common.dart';
+import '../build_info.dart';
+import '../globals.dart';
+import '../project.dart';
+
+import 'android_sdk.dart';
+import 'gradle.dart';
+
+Future<void> buildAppBundle({
+  @required FlutterProject project,
+  @required String target,
+  BuildInfo buildInfo = BuildInfo.debug
+}) async {
+  if (!project.android.isUsingGradle) {
+    throwToolExit(
+        'The build process for Android has changed, and the current project configuration\n'
+        'is no longer valid. Please consult\n\n'
+        'https://github.com/flutter/flutter/wiki/Upgrading-Flutter-projects-to-build-with-gradle\n\n'
+        'for details on how to upgrade the project.'
+    );
+  }
+
+  // Validate that we can find an android sdk.
+  if (androidSdk == null)
+    throwToolExit('No Android SDK found. Try setting the ANDROID_HOME environment variable.');
+
+  final List<String> validationResult = androidSdk.validateSdkWellFormed();
+  if (validationResult.isNotEmpty) {
+    for (String message in validationResult) {
+      printError(message, wrap: false);
+    }
+    throwToolExit('Try re-installing or updating your Android SDK.');
+  }
+
+  return buildGradleProject(
+    project: project,
+    buildInfo: buildInfo,
+    target: target,
+    isBuildingBundle: true
+  );
+}

packages/flutter_tools/lib/src/android/gradle.dart

@@ -125,6 +125,7 @@ Future<GradleProject> _readGradleProject() async {
     project = GradleProject(
       <String>['debug', 'profile', 'release'],
       <String>[], flutterProject.android.gradleAppOutV1Directory,
+        flutterProject.android.gradleAppBundleOutV1Directory
     );
   }
   status.stop();
@@ -284,6 +285,7 @@ Future<void> buildGradleProject({
   @required FlutterProject project,
   @required BuildInfo buildInfo,
   @required String target,
+  @required bool isBuildingBundle,
 }) async {
   // Update the local.properties file with the build mode, version name and code.
   // FlutterPlugin v1 reads local.properties to determine build mode. Plugin v2
@@ -305,7 +307,7 @@ Future<void> buildGradleProject({
     case FlutterPluginVersion.managed:
       // Fall through. Managed plugin builds the same way as plugin v2.
     case FlutterPluginVersion.v2:
-      return _buildGradleProjectV2(project, gradle, buildInfo, target);
+      return _buildGradleProjectV2(project, gradle, buildInfo, target, isBuildingBundle);
   }
 }
 
@@ -334,9 +336,18 @@ Future<void> _buildGradleProjectV2(
     FlutterProject flutterProject,
     String gradle,
     BuildInfo buildInfo,
-    String target) async {
+    String target,
+    bool isBuildingBundle) async {
   final GradleProject project = await _gradleProject();
-  final String assembleTask = project.assembleTaskFor(buildInfo);
+
+  String assembleTask;
+
+  if (isBuildingBundle) {
+    assembleTask = project.bundleTaskFor(buildInfo);
+  } else {
+    assembleTask = project.assembleTaskFor(buildInfo);
+  }
+
   if (assembleTask == null) {
     printError('');
     printError('The Gradle project does not define a task suitable for the requested build.');
@@ -406,89 +417,110 @@ Future<void> _buildGradleProjectV2(
   if (exitCode != 0)
     throwToolExit('Gradle task $assembleTask failed with exit code $exitCode', exitCode: exitCode);
 
-  final File apkFile = _findApkFile(project, buildInfo);
-  if (apkFile == null)
-    throwToolExit('Gradle build failed to produce an Android package.');
-  // Copy the APK to app.apk, so `flutter run`, `flutter install`, etc. can find it.
-  apkFile.copySync(project.apkDirectory.childFile('app.apk').path);
+  if(!isBuildingBundle) {
+    final File apkFile = _findApkFile(project, buildInfo);
+    if (apkFile == null)
+      throwToolExit('Gradle build failed to produce an Android package.');
+    // Copy the APK to app.apk, so `flutter run`, `flutter install`, etc. can find it.
+    apkFile.copySync(project.apkDirectory.childFile('app.apk').path);
 
-  printTrace('calculateSha: ${project.apkDirectory}/app.apk');
-  final File apkShaFile = project.apkDirectory.childFile('app.apk.sha1');
-  apkShaFile.writeAsStringSync(calculateSha(apkFile));
+    printTrace('calculateSha: ${project.apkDirectory}/app.apk');
+    final File apkShaFile = project.apkDirectory.childFile('app.apk.sha1');
+    apkShaFile.writeAsStringSync(calculateSha(apkFile));
 
-  String appSize;
-  if (buildInfo.mode == BuildMode.debug) {
-    appSize = '';
-  } else {
-    appSize = ' (${getSizeAsMB(apkFile.lengthSync())})';
-  }
-  printStatus('Built ${fs.path.relative(apkFile.path)}$appSize.');
-
-  if (buildInfo.createBaseline) {
-    // Save baseline apk for generating dynamic patches in later builds.
-    final AndroidApk package = AndroidApk.fromApk(apkFile);
-    final Directory baselineDir = fs.directory(buildInfo.baselineDir);
-    final File baselineApkFile = baselineDir.childFile('${package.versionCode}.apk');
-    baselineApkFile.parent.createSync(recursive: true);
-    apkFile.copySync(baselineApkFile.path);
-    printStatus('Saved baseline package ${baselineApkFile.path}.');
-  }
+    String appSize;
+    if (buildInfo.mode == BuildMode.debug) {
+      appSize = '';
+    } else {
+      appSize = ' (${getSizeAsMB(apkFile.lengthSync())})';
+    }
+    printStatus('Built ${fs.path.relative(apkFile.path)}$appSize.');
+
+    if (buildInfo.createBaseline) {
+      // Save baseline apk for generating dynamic patches in later builds.
+      final AndroidApk package = AndroidApk.fromApk(apkFile);
+      final Directory baselineDir = fs.directory(buildInfo.baselineDir);
+      final File baselineApkFile = baselineDir.childFile('${package.versionCode}.apk');
+      baselineApkFile.parent.createSync(recursive: true);
+      apkFile.copySync(baselineApkFile.path);
+      printStatus('Saved baseline package ${baselineApkFile.path}.');
+    }
 
-  if (buildInfo.createPatch) {
-    final AndroidApk package = AndroidApk.fromApk(apkFile);
+    if (buildInfo.createPatch) {
+      final AndroidApk package = AndroidApk.fromApk(apkFile);
     final Directory baselineDir = fs.directory(buildInfo.baselineDir);
-    final File baselineApkFile = baselineDir.childFile('${package.versionCode}.apk');
-    if (!baselineApkFile.existsSync())
-      throwToolExit('Error: Could not find baseline package ${baselineApkFile.path}.');
+    final File baselineApkFile = baselineDir.childFile('${package.versionCode}.apk');if (!baselineApkFile.existsSync())
+        throwToolExit('Error: Could not find baseline package ${baselineApkFile.path}.');
 
-    printStatus('Found baseline package ${baselineApkFile.path}.');
-    final Archive newApk = ZipDecoder().decodeBytes(apkFile.readAsBytesSync());
-    final Archive oldApk = ZipDecoder().decodeBytes(baselineApkFile.readAsBytesSync());
+      printStatus('Found baseline package ${baselineApkFile.path}.');
+      final Archive newApk = ZipDecoder().decodeBytes(apkFile.readAsBytesSync());
+      final Archive oldApk = ZipDecoder().decodeBytes(baselineApkFile.readAsBytesSync());
 
-    final Archive update = Archive();
-    for (ArchiveFile newFile in newApk) {
-      if (!newFile.isFile || !newFile.name.startsWith('assets/flutter_assets/'))
-        continue;
+      final Archive update = Archive();
+      for (ArchiveFile newFile in newApk) {
+        if (!newFile.isFile || !newFile.name.startsWith('assets/flutter_assets/'))
+          continue;
 
-      final ArchiveFile oldFile = oldApk.findFile(newFile.name);
-      if (oldFile != null && oldFile.crc32 == newFile.crc32)
-        continue;
+        final ArchiveFile oldFile = oldApk.findFile(newFile.name);
+        if (oldFile != null && oldFile.crc32 == newFile.crc32)
+          continue;
 
-      final String name = fs.path.relative(newFile.name, from: 'assets/');
-      update.addFile(ArchiveFile(name, newFile.content.length, newFile.content));
-    }
+        final String name = fs.path.relative(newFile.name, from: 'assets/');
+        update.addFile(ArchiveFile(name, newFile.content.length, newFile.content));
+      }
 
-    final File updateFile = fs.directory(buildInfo.patchDir)
-        .childFile('${package.versionCode}-${buildInfo.patchNumber}.zip');
+      final File updateFile = fs.directory(buildInfo.patchDir)
+          .childFile('${package.versionCode}-${buildInfo.patchNumber}.zip');
 
-    if (update.files.isEmpty) {
-      printStatus('No changes detected relative to baseline build.');
+      if (update.files.isEmpty) {
+        printStatus('No changes detected relative to baseline build.');
 
-      if (updateFile.existsSync()) {
-        updateFile.deleteSync();
-        printStatus('Deleted dynamic patch ${updateFile.path}.');
+        if (updateFile.existsSync()) {
+          updateFile.deleteSync();
+          printStatus('Deleted dynamic patch ${updateFile.path}.');
+        }
+        return;
       }
-      return;
-    }
 
-    final ArchiveFile oldFile = oldApk.findFile('assets/flutter_assets/isolate_snapshot_data');
-    if (oldFile == null)
-      throwToolExit('Error: Could not find baseline assets/flutter_assets/isolate_snapshot_data.');
+      final ArchiveFile oldFile = oldApk.findFile('assets/flutter_assets/isolate_snapshot_data');
+      if (oldFile == null)
+        throwToolExit('Error: Could not find baseline assets/flutter_assets/isolate_snapshot_data.');
 
-    final int baselineChecksum = getCrc32(oldFile.content);
-    final Map<String, dynamic> manifest = <String, dynamic>{
-      'baselineChecksum': baselineChecksum,
-      'buildNumber': package.versionCode,
-      'patchNumber': buildInfo.patchNumber,
-    };
+      final int baselineChecksum = getCrc32(oldFile.content);
+      final Map<String, dynamic> manifest = <String, dynamic>{
+        'baselineChecksum': baselineChecksum,
+        'buildNumber': package.versionCode,
+        'patchNumber': buildInfo.patchNumber,
+      };
 
-    const JsonEncoder encoder = JsonEncoder.withIndent('  ');
-    final String manifestJson = encoder.convert(manifest);
-    update.addFile(ArchiveFile('manifest.json', manifestJson.length, manifestJson.codeUnits));
+      const JsonEncoder encoder = JsonEncoder.withIndent('  ');
+      final String manifestJson = encoder.convert(manifest);
+      update.addFile(ArchiveFile('manifest.json', manifestJson.length, manifestJson.codeUnits));
 
-    updateFile.parent.createSync(recursive: true);
-    updateFile.writeAsBytesSync(ZipEncoder().encode(update), flush: true);
-    printStatus('Created dynamic patch ${updateFile.path}.');
+      updateFile.parent.createSync(recursive: true);
+      updateFile.writeAsBytesSync(ZipEncoder().encode(update), flush: true);
+      printStatus('Created dynamic patch ${updateFile.path}.');
+    }
+  } else {
+    final File bundleFile = _findBundleFile(project, buildInfo);
+    if (bundleFile == null)
+      throwToolExit('Gradle build failed to produce an Android bundle package.');
+    // Copy the bundle to app.aab, so `flutter run`, `flutter install`, etc. can find it.
+    bundleFile.copySync(project.bundleDirectory
+        .childFile('app.aab')
+        .path);
+
+    printTrace('calculateSha: ${project.bundleDirectory}/app.aab');
+    final File bundleShaFile = project.bundleDirectory.childFile('app.aab.sha1');
+    bundleShaFile.writeAsStringSync(calculateSha(bundleFile));
+
+    String appSize;
+    if (buildInfo.mode == BuildMode.debug) {
+      appSize = '';
+    } else {
+      appSize = ' (${getSizeAsMB(bundleFile.lengthSync())})';
+    }
+    printStatus('Built ${fs.path.relative(bundleFile.path)}$appSize.');
   }
 }
 
@@ -512,6 +544,28 @@ File _findApkFile(GradleProject project, BuildInfo buildInfo) {
   return null;
 }
 
+File _findBundleFile(GradleProject project, BuildInfo buildInfo) {
+  final String bundleFileName = project.bundleFileFor(buildInfo);
+
+  if (bundleFileName == null)
+    return null;
+  File bundleFile = fs.file(fs.path.join(project.bundleDirectory.path, bundleFileName));
+  if (bundleFile.existsSync()) {
+    return bundleFile;
+  }
+  final String modeName = camelCase(buildInfo.modeName);
+  bundleFile = fs.file(fs.path.join(project.bundleDirectory.path, modeName, bundleFileName));
+  if (bundleFile.existsSync())
+    return bundleFile;
+  if (buildInfo.flavor != null) {
+    // Android Studio Gradle plugin v3 adds the flavor to the path. For the bundle the folder name is the flavor plus the mode name.
+    bundleFile = fs.file(fs.path.join(project.bundleDirectory.path, buildInfo.flavor + modeName, bundleFileName));
+    if (bundleFile.existsSync())
+      return bundleFile;
+  }
+  return null;
+}
+
 Map<String, String> get _gradleEnv {
   final Map<String, String> env = Map<String, String>.from(platform.environment);
   if (javaPath != null) {
@@ -522,7 +576,7 @@ Map<String, String> get _gradleEnv {
 }
 
 class GradleProject {
-  GradleProject(this.buildTypes, this.productFlavors, this.apkDirectory);
+  GradleProject(this.buildTypes, this.productFlavors, this.apkDirectory, this.bundleDirectory);
 
   factory GradleProject.fromAppProperties(String properties, String tasks) {
     // Extract build directory.
@@ -561,12 +615,14 @@ class GradleProject {
       buildTypes.toList(),
       productFlavors.toList(),
       fs.directory(fs.path.join(buildDir, 'outputs', 'apk')),
+      fs.directory(fs.path.join(buildDir, 'outputs', 'bundle')),
     );
   }
 
   final List<String> buildTypes;
   final List<String> productFlavors;
   final Directory apkDirectory;
+  final Directory bundleDirectory;
 
   String _buildTypeFor(BuildInfo buildInfo) {
     final String modeName = camelCase(buildInfo.modeName);
@@ -600,4 +656,18 @@ class GradleProject {
     final String flavorString = productFlavor.isEmpty ? '' : '-' + productFlavor;
     return 'app$flavorString-$buildType.apk';
   }
+
+  String bundleTaskFor(BuildInfo buildInfo) {
+    final String buildType = _buildTypeFor(buildInfo);
+    final String productFlavor = _productFlavorFor(buildInfo);
+    if (buildType == null || productFlavor == null)
+      return null;
+    return 'bundle${toTitleCase(productFlavor)}${toTitleCase(buildType)}';
+  }
+
+  String bundleFileFor(BuildInfo buildInfo) {
+    // For app bundle all bundle names are called as app.aab. Product flavors
+    // & build types are differentiated as folders, where the aab will be added.
+    return 'app.aab';
+  }
 }

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

@@ -12,13 +12,15 @@ import '../globals.dart';
 import '../runner/flutter_command.dart';
 import 'build_aot.dart';
 import 'build_apk.dart';
+import 'build_appbundle.dart';
 import 'build_bundle.dart';
 import 'build_flx.dart';
 import 'build_ios.dart';
 
 class BuildCommand extends FlutterCommand {
   BuildCommand({bool verboseHelp = false}) {
     addSubcommand(BuildApkCommand(verboseHelp: verboseHelp));
+    addSubcommand(BuildAppBundleCommand(verboseHelp: verboseHelp));
     addSubcommand(BuildAotCommand());
     addSubcommand(BuildIOSCommand());
     addSubcommand(BuildFlxCommand());