Revert "Fix how Gradle resolves Android plugin" (#98050)

packages/flutter_tools/gradle/app_plugin_loader.gradle

@@ -20,7 +20,6 @@ assert object instanceof Map
 assert object.plugins instanceof Map
 assert object.plugins.android instanceof List
 // Includes the Flutter plugins that support the Android platform.
-// This logic must be kept in sync with the logic in flutter.gradle.
 object.plugins.android.each { androidPlugin ->
   assert androidPlugin.name instanceof String
   assert androidPlugin.path instanceof String

packages/flutter_tools/gradle/flutter.gradle

@@ -48,7 +48,7 @@ class FlutterExtension {
      * Specifies the relative directory to the Flutter project directory.
      * In an app project, this is ../.. since the app's build.gradle is under android/app.
      */
-    String source = '../..'
+    String source
 
     /** Allows to override the target file. Otherwise, the target is lib/main.dart. */
     String target
@@ -418,7 +418,7 @@ class FlutterPlugin implements Plugin<Project> {
 
     /**
      * Compares semantic versions ignoring labels.
-     *
+     * 
      * If the versions are equal (ignoring labels), returns one of the two strings arbitrarily.
      *
      * If minor or patch are omitted (non-conformant to semantic versioning), they are considered zero.
@@ -459,9 +459,6 @@ class FlutterPlugin implements Plugin<Project> {
 
             getPluginList().each { plugin ->
                 Project pluginProject = project.rootProject.findProject(plugin.key)
-                if (pluginProject == null) {
-                    return
-                }
                 pluginProject.afterEvaluate {
                     int pluginCompileSdkVersion = pluginProject.android.compileSdkVersion.substring(8) as int
                     maxPluginCompileSdkVersion = Math.max(pluginCompileSdkVersion, maxPluginCompileSdkVersion)
@@ -479,7 +476,15 @@ class FlutterPlugin implements Plugin<Project> {
                     }
                 }
             }
-        }
+        }  
+    }
+
+    /**
+     * Returns `true` if the given path contains an `android/build.gradle` file.
+     */
+    private Boolean doesSupportAndroidPlatform(String path) {
+        File editableAndroidProject = new File(path, 'android' + File.separator + 'build.gradle')
+        return editableAndroidProject.exists()
     }
 
     /**
@@ -490,7 +495,8 @@ class FlutterPlugin implements Plugin<Project> {
     private void configurePluginDependencies(Object dependencyObject) {
         assert dependencyObject.name instanceof String
         Project pluginProject = project.rootProject.findProject(":${dependencyObject.name}")
-        if (pluginProject == null) {
+        if (pluginProject == null ||
+            !doesSupportAndroidPlatform(pluginProject.projectDir.parentFile.path)) {
             return
         }
         assert dependencyObject.dependencies instanceof List
@@ -500,7 +506,8 @@ class FlutterPlugin implements Plugin<Project> {
                 return
             }
             Project dependencyProject = project.rootProject.findProject(":$pluginDependencyName")
-            if (dependencyProject == null) {
+            if (dependencyProject == null ||
+                !doesSupportAndroidPlatform(dependencyProject.projectDir.parentFile.path)) {
                 return
             }
             // Wait for the Android plugin to load and add the dependency to the plugin project.
@@ -512,27 +519,17 @@ class FlutterPlugin implements Plugin<Project> {
         }
     }
 
-    /** Gets the list of plugins that support the Android platform. */
     private Properties getPluginList() {
-        Map meta = getDependenciesMetadata()
+        File pluginsFile = new File(project.projectDir.parentFile.parentFile, '.flutter-plugins')
+        Properties allPlugins = readPropertiesIfExist(pluginsFile)
         Properties androidPlugins = new Properties()
-        if (meta == null) {
-            return androidPlugins
-        }
-        assert meta.plugins instanceof Map
-        assert meta.plugins.android instanceof List
-
-        // This logic must be kept in sync with the logic in app_plugin_loader.gradle.
-        meta.plugins.android.each { androidPlugin ->
-            assert androidPlugin.name instanceof String
-            assert androidPlugin.path instanceof String
-            // Skip plugins that have no native build (such as a Dart-only implementation
-            // of a federated plugin).
-            def needsBuild = androidPlugin.containsKey('native_build') ? androidPlugin['native_build'] : true
-            if (!needsBuild) {
-                return
+        allPlugins.each { name, path ->
+            if (doesSupportAndroidPlatform(path)) {
+                androidPlugins.setProperty(name, path)
             }
-            androidPlugins.setProperty(androidPlugin.name, androidPlugin.path)
+            // TODO(amirh): log an error if this plugin was specified to be an Android
+            // plugin according to the new schema, and was missing a build.gradle file.
+            // https://github.com/flutter/flutter/issues/40784
         }
         return androidPlugins
     }
@@ -560,31 +557,14 @@ class FlutterPlugin implements Plugin<Project> {
         // This means, `plugin-a` depends on `plugin-b` and `plugin-c`.
         // `plugin-b` depends on `plugin-c`.
         // `plugin-c` doesn't depend on anything.
-        Map meta = getDependenciesMetadata()
-        if (meta == null) {
-            return []
-        }
-        assert meta.dependencyGraph instanceof List
-        return meta.dependencyGraph
-    }
-
-    private Map parsedFlutterPluginsDependencies
-
-    /**
-     * Parses <project-src>/.flutter-plugins-dependencies
-     */
-    private Map getDependenciesMetadata() {
-        if (parsedFlutterPluginsDependencies) {
-            return parsedFlutterPluginsDependencies
-        }
-        File pluginsDependencyFile = new File(getFlutterSourceDirectory(), '.flutter-plugins-dependencies')
+        File pluginsDependencyFile = new File(project.projectDir.parentFile.parentFile, '.flutter-plugins-dependencies')
         if (pluginsDependencyFile.exists()) {
             def object = new JsonSlurper().parseText(pluginsDependencyFile.text)
             assert object instanceof Map
-            parsedFlutterPluginsDependencies = object
-            return object
+            assert object.dependencyGraph instanceof List
+            return object.dependencyGraph
         }
-        return null
+        return []
     }
 
     private static String toCammelCase(List<String> parts) {

packages/flutter_tools/test/integration.shard/android_skip_unsupported_plugin.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 'package:file_testing/file_testing.dart';
-import 'package:flutter_tools/src/base/file_system.dart';
-import 'package:flutter_tools/src/base/io.dart';
-import 'package:flutter_tools/src/cache.dart';
-
-import '../src/common.dart';
-import 'test_utils.dart';
-
-void main() {
-  late Directory tempDir;
-
-  setUp(() {
-    Cache.flutterRoot = getFlutterRoot();
-    tempDir = createResolvedTempDirectorySync('flutter_plugin_test.');
-  });
-
-  tearDown(() async {
-    tryToDelete(tempDir);
-  });
-
-  // Regression test for https://github.com/flutter/flutter/issues/97729.
-  test('skip plugin if it does not support the Android platform', () async {
-    final String flutterBin = fileSystem.path.join(
-      getFlutterRoot(),
-      'bin',
-      'flutter',
-    );
-
-    // Create dummy plugin that *only* supports iOS.
-    processManager.runSync(<String>[
-      flutterBin,
-      ...getLocalEngineArguments(),
-      'create',
-      '--template=plugin',
-      '--platforms=ios',
-      'test_plugin',
-    ], workingDirectory: tempDir.path);
-
-    final Directory pluginAppDir = tempDir.childDirectory('test_plugin');
-
-    // Create an android directory and a build.gradle file within.
-    final File pluginGradleFile = pluginAppDir
-        .childDirectory('android')
-        .childFile('build.gradle')
-      ..createSync(recursive: true);
-    expect(pluginGradleFile, exists);
-
-    pluginGradleFile.writeAsStringSync(r'''
-buildscript {
-    ext.kotlin_version = '1.5.31'
-    repositories {
-        google()
-        mavenCentral()
-    }
-
-    dependencies {
-        classpath 'com.android.tools.build:gradle:7.0.0'
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
-    }
-
-    configurations.classpath {
-        resolutionStrategy.activateDependencyLocking()
-    }
-}
-
-allprojects {
-    repositories {
-        google()
-        mavenCentral()
-    }
-}
-
-rootProject.buildDir = '../build'
-
-subprojects {
-    project.buildDir = "${rootProject.buildDir}/${project.name}"
-}
-
-subprojects {
-    project.evaluationDependsOn(':app')
-}
-
-task clean(type: Delete) {
-    delete rootProject.buildDir
-}
-''');
-
-    final Directory pluginExampleAppDir =
-        pluginAppDir.childDirectory('example');
-
-    // Add android support to the plugin's example app.
-    final ProcessResult addAndroidResult = processManager.runSync(<String>[
-      flutterBin,
-      ...getLocalEngineArguments(),
-      'create',
-      '--template=app',
-      '--platforms=android',
-      '.',
-    ], workingDirectory: pluginExampleAppDir.path);
-    expect(addAndroidResult.exitCode, equals(0),
-        reason:
-            'flutter create exited with non 0 code: ${addAndroidResult.stderr}');
-
-    // Run flutter build apk to build plugin example project.
-    final ProcessResult buildApkResult = processManager.runSync(<String>[
-      flutterBin,
-      ...getLocalEngineArguments(),
-      'build',
-      'apk',
-      '--debug',
-    ], workingDirectory: pluginExampleAppDir.path);
-    expect(buildApkResult.exitCode, equals(0),
-        reason:
-            'flutter build apk exited with non 0 code: ${buildApkResult.stderr}');
-  });
-}