[Android] Fix integration test to check if dev dependencies are removed from release builds + address no non-dev dependency plugin edge case (#161826)

Makes the following change to fix the case where dev dependencies are
stripped in apps that only contain dev dependencies:
- Changes the Flutter Gradle plugin to add the Flutter embedding as a
direct dependency of a Flutter app if it contains no plugins that would
include it transitively (this excludes dev dependencies in release
builds)

Makes the following changes to correct + improve the integration test
that checks if dev dependencies are stripped from release builds:

- Fixes the plugin that was supposed to be as dev dependency to actually
be a dev dependency
- Changes the test structure to check the output of `./gradlew
app:dependencies` (see [more details on this
call](https://docs.gradle.org/current/userguide/viewing_debugging_dependencies.html))
instead of the classes included in the APK. Checking the APK was leading
us astray because it appears obfuscation occurs for release builds.
- Adds more sections, comments, etc.

Fixes https://github.com/flutter/flutter/issues/161780.

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [ ] All existing and new tests are passing.


<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

---------

Co-authored-by: Matan Lurey <matan@lurey.org>

dev/devicelab/bin/tasks/android_release_builds_exclude_dev_dependencies_test.dart

@@ -8,72 +8,100 @@ import 'dart:io';
 import 'package:flutter_devicelab/framework/apk_utils.dart';
 import 'package:flutter_devicelab/framework/framework.dart';
 import 'package:flutter_devicelab/framework/task_result.dart';
-import 'package:flutter_devicelab/framework/utils.dart';
+import 'package:flutter_devicelab/framework/utils.dart' as utils;
 import 'package:path/path.dart' as path;
 
 Future<void> main() async {
   await task(() async {
     try {
       await runProjectTest((FlutterProject flutterProject) async {
+        utils.section(
+          'Configure plugins to be marked as dev dependencies in .flutter-plugins-dependencies file',
+        );
+
         // Enable plugins being marked as dev dependncies in the .flutter-plugins-dependencies file.
-        await flutter('config', options: <String>['--explicit-package-dependencies']);
+        await utils.flutter('config', options: <String>['--explicit-package-dependencies']);
 
         // Create dev_dependency plugin to use for test.
         final Directory tempDir = Directory.systemTemp.createTempSync(
           'android_release_builds_exclude_dev_dependencies_test.',
         );
         const String devDependencyPluginOrg = 'com.example.dev_dependency_plugin';
+
+        utils.section('Create plugin dev_dependency_plugin that supports Android');
+
         await FlutterPluginProject.create(
           tempDir,
           'dev_dependency_plugin',
           options: <String>['--platforms=android', '--org=$devDependencyPluginOrg'],
         );
 
+        utils.section('Add dev_dependency_plugin as a dev dependency to the Flutter app project');
+
         // Add devDependencyPlugin as dependency of flutterProject.
         await flutterProject.addPlugin(
-          'dev_dependency_plugin',
+          'dev:dev_dependency_plugin',
           options: <String>['--path', path.join(tempDir.path, 'dev_dependency_plugin')],
         );
 
+        utils.section(
+          'Verify the app includes/excludes dev_dependency_plugin as dependency in each build mode as expected',
+        );
         final List<String> buildModesToTest = <String>['debug', 'profile', 'release'];
         for (final String buildMode in buildModesToTest) {
-          section('APK does contain methods from dev dependency in $buildMode mode');
+          final String gradlew = Platform.isWindows ? 'gradlew.bat' : 'gradlew';
+          final String gradlewExecutable = Platform.isWindows ? '.\\$gradlew' : './$gradlew';
+          final RegExp regExpToMatchDevDependencyPlugin = RegExp(
+            r'--- project :dev_dependency_plugin',
+          );
+          final RegExp regExpToMatchDevDependencyPluginWithTransitiveDependencies = RegExp(
+            r'--- project :dev_dependency_plugin\n(\s)*\+--- org.jetbrains.kotlin.*\s\(\*\)\n(\s)*\\---\sio.flutter:flutter_embedding_' +
+                buildMode,
+          );
+          const String stringToMatchFlutterEmbedding = '+--- io.flutter:flutter_embedding_release:';
+          final bool isTestingReleaseMode = buildMode == 'release';
 
-          // Build APK in buildMode and check that devDependencyPlugin is included/excluded in the APK as expected.
+          utils.section('Query the dependencies of the app built with $buildMode');
-          await inDirectory(flutterProject.rootPath, () async {
+
-            await flutter(
+          final String appDependencies = await utils.eval(gradlewExecutable, <String>[
-              'build',
+            'app:dependencies',
-              options: <String>['apk', '--$buildMode', '--target-platform=android-arm'],
+            '--configuration',
+            '${buildMode}RuntimeClasspath',
+          ], workingDirectory: flutterProject.androidPath);
+
+          if (isTestingReleaseMode) {
+            utils.section(
+              'Check that the release build includes Flutter embedding as a direct dependency',
             );
 
-            final File apk = File(
+            if (!appDependencies.contains(stringToMatchFlutterEmbedding)) {
-              path.join(
+              // We expect dev_dependency_plugin to not be included in the dev dependency, but the Flutter
-                flutterProject.rootPath,
+              // embedding should still be a dependency of the app project (regardless of the fact
-                'build',
+              // that the app does not depend on any plugins that support Android, which would cause the
-                'app',
+              // Flutter embedding to be included as a transitive dependency).
-                'outputs',
-                'flutter-apk',
-                'app-$buildMode.apk',
-              ),
-            );
-            if (!apk.existsSync()) {
-              throw TaskResult.failure("Expected ${apk.path} to exist, but it doesn't.");
-            }
-
-            // We expect the APK to include the devDependencyPlugin except in release mode.
-            final bool isTestingReleaseMode = buildMode == 'release';
-            final bool apkIncludesDevDependency = await checkApkContainsMethodsFromLibrary(
-              apk,
-              devDependencyPluginOrg,
-            );
-            final bool apkIncludesDevDependencyAsExpected =
-                isTestingReleaseMode ? !apkIncludesDevDependency : apkIncludesDevDependency;
-            if (!apkIncludesDevDependencyAsExpected) {
               throw TaskResult.failure(
-                'Expected to${isTestingReleaseMode ? ' not' : ''} find dev_dependency_plugin in APK built with debug mode but did${isTestingReleaseMode ? '' : ' not'}.',
+                'Expected to find the Flutter embedding as a dependency of the release app build, but did not.',
               );
             }
-          });
+          }
+
+          utils.section(
+            'Check that the $buildMode build includes/excludes the dev dependency plugin as expected',
+          );
+
+          // Ensure that release builds have no reference to the dev dependency plugin and make sure
+          // that it is included with expected transitive dependencies for debug, profile builds.
+          final bool appIncludesDevDependencyAsExpected =
+              isTestingReleaseMode
+                  ? !appDependencies.contains(regExpToMatchDevDependencyPlugin)
+                  : appDependencies.contains(
+                    regExpToMatchDevDependencyPluginWithTransitiveDependencies,
+                  );
+          if (!appIncludesDevDependencyAsExpected) {
+            throw TaskResult.failure(
+              'Expected to${isTestingReleaseMode ? ' not' : ''} find dev_dependency_plugin as a dependency of the app built in $buildMode mode but did${isTestingReleaseMode ? '' : ' not'}.',
+            );
+          }
         }
       });
       return TaskResult.success(null);

packages/flutter_tools/gradle/src/main/groovy/flutter.groovy

@@ -590,11 +590,13 @@ class FlutterPlugin implements Plugin<Project> {
         }
         // The embedding is set as an API dependency in a Flutter plugin.
         // Therefore, don't make the app project depend on the embedding if there are Flutter
-        // plugins.
+        // plugin dependencies. In release mode, dev dependencies are stripped, so we do not
+        // consider those in the check.
         // This prevents duplicated classes when using custom build types. That is, a custom build
         // type like profile is used, and the plugin and app projects have API dependencies on the
         // embedding.
-        if (!isFlutterAppProject() || getPluginList(project).size() == 0) {
+        List<Map<String, Object>> pluginsThatIncludeFlutterEmbeddingAsTransitiveDependency = flutterBuildMode == "release" ? getPluginListWithoutDevDependencies(project) : getPluginList(project);
+        if (!isFlutterAppProject() || pluginsThatIncludeFlutterEmbeddingAsTransitiveDependency.size() == 0) {
             addApiDependencies(project, buildType.name,
                     "io.flutter:flutter_embedding_$flutterBuildMode:$engineVersion")
         }
@@ -988,6 +990,24 @@ class FlutterPlugin implements Plugin<Project> {
         return pluginList
     }
 
+    /**
+     * Gets the list of plugins (as map) that support the Android platform and are dependencies of the
+     * Android project excluding dev dependencies.
+     *
+     * The map value contains either the plugins `name` (String),
+     * its `path` (String), or its `dependencies` (List<String>).
+     * See [NativePluginLoader#getPlugins] in packages/flutter_tools/gradle/src/main/groovy/native_plugin_loader.groovy
+     */
+    private List<Map<String, Object>> getPluginListWithoutDevDependencies(Project project) {
+        List<Map<String, Object>> pluginListWithoutDevDependencies = []
+        for (Map<String, Object> plugin in getPluginList(project)) {
+            if (!plugin.dev_dependency) {
+                pluginListWithoutDevDependencies += plugin
+            }
+        }
+        return pluginListWithoutDevDependencies
+    }
+
     // TODO(54566, 48918): Remove in favor of [getPluginList] only, see also
     //  https://github.com/flutter/flutter/blob/1c90ed8b64d9ed8ce2431afad8bc6e6d9acc4556/packages/flutter_tools/lib/src/flutter_plugins.dart#L212
     /** Gets the plugins dependencies from `.flutter-plugins-dependencies`. */