Fix plugin java class desugar (#73758)

dev/devicelab/bin/tasks/gradle_desugar_classes_test.dart

+// Copyright 2014 The Flutter 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: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';
+
+
+Future<void> main() async {
+  await task(() async {
+    try {
+      await runProjectTest((FlutterProject flutterProject) async {
+        section('APK contains plugin classes');
+        flutterProject.addPlugin('google_maps_flutter', value: '^1.0.10');
+
+        await inDirectory(flutterProject.rootPath, () async {
+          await flutter('build', options: <String>[
+            'apk',
+            '--debug',
+            '--target-platform=android-arm',
+          ]);
+          final File apk = File('${flutterProject.rootPath}/build/app/outputs/flutter-apk/app-debug.apk');
+          if (!apk.existsSync()) {
+            throw TaskResult.failure('Expected ${apk.path} to exist, but it doesn\'t');
+          }
+          // https://github.com/flutter/flutter/issues/72185
+          await checkApkContainsMethods(apk, <String>[
+            'io.flutter.plugins.googlemaps.GoogleMapController void onFlutterViewAttached(android.view.View)',
+            'io.flutter.plugins.googlemaps.GoogleMapController void onFlutterViewDetached()',
+          ]);
+        });
+      });
+      return TaskResult.success(null);
+    } on TaskResult catch (taskResult) {
+      return taskResult;
+    } catch (e) {
+      return TaskResult.failure(e.toString());
+    }
+  });
+}

dev/devicelab/lib/framework/apk_utils.dart

@@ -115,12 +115,14 @@ String get _androidHome {
 /// Executes an APK analyzer subcommand.
 Future<String> _evalApkAnalyzer(
   List<String> args, {
-  bool printStdout = true,
+  bool printStdout = false,
   String workingDirectory,
 }) async {
   final String javaHome = await findJavaHome();
-
-   final String apkAnalyzer = path
+  if (javaHome == null || javaHome.isEmpty) {
+    throw Exception('No JAVA_HOME set.');
+  }
+  final String apkAnalyzer = path
      .join(_androidHome, 'cmdline-tools', 'latest', 'bin', Platform.isWindows ? 'apkanalyzer.bat' : 'apkanalyzer');
    if (canRun(apkAnalyzer)) {
      return eval(
@@ -165,6 +167,7 @@ class ApkExtractor {
   bool _extracted = false;
 
   Set<String> _classes = const <String>{};
+  Set<String> _methods = const <String>{};
 
   Future<void> _extractDex() async {
     if (_extracted) {
@@ -177,22 +180,17 @@ class ApkExtractor {
         apkFile.path,
       ],
     );
+    final List<String> lines = packages.split('\n');
     _classes = Set<String>.from(
-      packages
-        .split('\n')
-        .where((String line) => line.startsWith('C'))
-        .map<String>((String line) => line.split('\t').last),
+      lines.where((String line) => line.startsWith('C'))
+           .map<String>((String line) => line.split('\t').last),
     );
     assert(_classes.isNotEmpty);
-    _extracted = true;
-  }
-
-  // Removes any temporary directory.
-  void dispose() {
-    if (!_extracted) {
-      return;
-    }
-    _classes = const <String>{};
+    _methods = Set<String>.from(
+      lines.where((String line) => line.startsWith('M'))
+           .map<String>((String line) => line.split('\t').last)
+    );
+    assert(_methods.isNotEmpty);
     _extracted = true;
   }
 
@@ -201,6 +199,13 @@ class ApkExtractor {
     await _extractDex();
     return _classes.contains(className);
   }
+
+  /// Returns true if the APK contains a given method.
+  /// For example: io.flutter.plugins.googlemaps.GoogleMapController void onFlutterViewAttached(android.view.View)
+  Future<bool> containsMethod(String methodName) async {
+    await _extractDex();
+    return _methods.contains(methodName);
+  }
 }
 
 /// Gets the content of the `AndroidManifest.xml`.
@@ -223,7 +228,16 @@ Future<void> checkApkContainsClasses(File apk, List<String> classes) async {
       throw Exception("APK doesn't contain class `$className`.");
     }
   }
-  extractor.dispose();
+}
+
+/// Checks that the methods are defined in the APK, throws otherwise.
+Future<void> checkApkContainsMethods(File apk, List<String> methods) async {
+  final ApkExtractor extractor = ApkExtractor(apk);
+  for (final String method in methods) {
+    if (!(await extractor.containsMethod(method))) {
+      throw Exception("APK doesn't contain method `$method`.");
+    }
+  }
 }
 
 class FlutterProject {
@@ -288,7 +302,7 @@ subprojects {
     String content = await pubspec.readAsString();
     content = content.replaceFirst(
       '${platformLineSep}dependencies:$platformLineSep',
-      '${platformLineSep}dependencies:$platformLineSep  $plugin:$value$platformLineSep',
+      '${platformLineSep}dependencies:$platformLineSep  $plugin: $value$platformLineSep',
     );
     await pubspec.writeAsString(content, flush: true);
   }

dev/devicelab/lib/framework/utils.dart

@@ -456,6 +456,8 @@ List<String> flutterCommandArgs(String command, List<String> options) {
   ];
 }
 
+/// Runs the flutter `command`, and returns the exit code.
+/// If `canFail` is `false`, the future completes with an error.
 Future<int> flutter(String command, {
   List<String> options = const <String>[],
   bool canFail = false, // as in, whether failures are ok. False means that they are fatal.

packages/flutter_tools/gradle/flutter.gradle

@@ -101,6 +101,19 @@ class FlutterPlugin implements Plugin<Project> {
     void apply(Project project) {
         this.project = project
 
+        // Configure the Maven repository.
+        String hostedRepository = System.env.FLUTTER_STORAGE_BASE_URL ?: DEFAULT_MAVEN_HOST
+        String repository = useLocalEngine()
+            ? project.property('local-engine-repo')
+            : "$hostedRepository/download.flutter.io"
+        project.rootProject.allprojects {
+            repositories {
+                maven {
+                    url repository
+                }
+            }
+        }
+
         project.extensions.create("flutter", FlutterExtension)
         this.addFlutterTasks(project)
 
@@ -184,8 +197,7 @@ class FlutterPlugin implements Plugin<Project> {
             localEngine = engineOut.name
             localEngineSrcPath = engineOut.parentFile.parent
         }
-        project.android.buildTypes.each this.&addFlutterDependencies
-        project.android.buildTypes.whenObjectAdded this.&addFlutterDependencies
+        project.android.buildTypes.all this.&addFlutterDependencies
     }
 
     /**
@@ -199,21 +211,16 @@ class FlutterPlugin implements Plugin<Project> {
         if (!supportsBuildMode(flutterBuildMode)) {
             return
         }
-        String hostedRepository = System.env.FLUTTER_STORAGE_BASE_URL ?: DEFAULT_MAVEN_HOST
-        String repository = useLocalEngine()
-            ? project.property('local-engine-repo')
-            : "$hostedRepository/download.flutter.io"
-        project.rootProject.allprojects {
-            repositories {
-                maven {
-                    url repository
-                }
-            }
+        // The embedding is set as an API dependency in a Flutter plugin.
+        // Therefore, don't make the app project depend on the embedding if there are Flutter
+        // plugins.
+        // This prevents duplicated classes when using custom build types. That is, a custom build
+        // type like profile is used, and the plugin and app projects have API dependencies on the
+        // embedding.
+        if (!isFlutterAppProject() || getPluginList().size() == 0) {
+            addApiDependencies(project, buildType.name,
+                    "io.flutter:flutter_embedding_$flutterBuildMode:$engineVersion")
         }
-        // Add the embedding dependency.
-        addApiDependencies(project, buildType.name,
-                "io.flutter:flutter_embedding_$flutterBuildMode:$engineVersion")
-
         List<String> platforms = getTargetPlatforms().collect()
         // Debug mode includes x86 and x64, which are commonly used in emulators.
         if (flutterBuildMode == "debug" && !useLocalEngine()) {
@@ -303,7 +310,7 @@ class FlutterPlugin implements Plugin<Project> {
         }
         // Add plugin dependency to the app project.
         project.dependencies {
-            implementation pluginProject
+            api pluginProject
         }
         Closure addEmbeddingDependencyToPlugin = { buildType ->
             String flutterBuildMode = buildModeFor(buildType)
@@ -318,39 +325,23 @@ class FlutterPlugin implements Plugin<Project> {
             pluginProject.android.buildTypes {
                 "${buildType.name}" {}
             }
-            // The embedding is a compileOnly dependency of a Flutter plugin,
-            // however prior to Gradle 6.0.0, it must be an API dependency.
+            // The embedding is API dependency of the plugin, so the AGP is able to desugar
+            // default method implementations when the interface is implemented by a plugin.
             //
-            // Not doing so, causes transitive dependency resolution conflicts.
-            // That is, the embedding dependencies resolved in the plugin are
-            // different than the ones resolved in the app.
-            if (isGradleVersionGraterOrEqualThan('6.0.0')) {
-              addCompileOnlyDependency(
-                pluginProject,
-                buildType.name,
-                "io.flutter:flutter_embedding_$flutterBuildMode:$engineVersion"
-              )
-            } else {
-              addApiDependencies(
-                pluginProject,
-                buildType.name,
-                "io.flutter:flutter_embedding_$flutterBuildMode:$engineVersion"
-              )
-            }
+            // See https://issuetracker.google.com/139821726, and
+            // https://github.com/flutter/flutter/issues/72185 for more details.
+            addApiDependencies(
+              pluginProject,
+              buildType.name,
+              "io.flutter:flutter_embedding_$flutterBuildMode:$engineVersion"
+            )
         }
         // Wait until the Android plugin loaded.
         pluginProject.afterEvaluate {
-            project.android.buildTypes.each addEmbeddingDependencyToPlugin
-            project.android.buildTypes.whenObjectAdded addEmbeddingDependencyToPlugin
+            project.android.buildTypes.all addEmbeddingDependencyToPlugin
         }
     }
 
-    // Returns `true` if the current Gradle version is greater or equal to the given version.
-    private isGradleVersionGraterOrEqualThan(String version) {
-      return VersionNumber.parse(project.gradle.gradleVersion)
-          .compareTo(VersionNumber.parse(version)) >= 0
-    }
-
     // Returns `true` if the given path contains an `android/build.gradle` file.
     //
     // TODO(egarciad): Fix https://github.com/flutter/flutter/issues/39657.
@@ -659,6 +650,10 @@ class FlutterPlugin implements Plugin<Project> {
         return variant.hasProperty("assembleProvider") ? variant.assembleProvider.get() : variant.assemble
     }
 
+    private boolean isFlutterAppProject() {
+        return project.android.hasProperty("applicationVariants")
+    }
+
     private void addFlutterTasks(Project project) {
         if (project.state.failure) {
             return
@@ -816,8 +811,7 @@ class FlutterPlugin implements Plugin<Project> {
             }
             return copyFlutterAssetsTask
         }
-        boolean isFlutterAppProject = project.android.hasProperty("applicationVariants")
-        if (isFlutterAppProject) {
+        if (isFlutterAppProject()) {
             project.android.applicationVariants.all { variant ->
                 Task assembleTask = getAssembleTask(variant)
                 if (!shouldConfigureFlutterTask(assembleTask)) {