[federated_plugin] adds platform interface implementation and plugin implementation for Android (#503)

experimental/federated_plugin/federated_plugin/android/build.gradle

@@ -40,4 +40,5 @@ android {
 
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
+    implementation 'com.google.android.gms:play-services-location:17.0.0'
 }

experimental/federated_plugin/federated_plugin/android/src/main/AndroidManifest.xml

@@ -1,3 +1,5 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="dev.flutter.federated_plugin">
+    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
+    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
 </manifest>

experimental/federated_plugin/federated_plugin/android/src/main/kotlin/dev/flutter/federated_plugin/FederatedPlugin.kt

@@ -4,37 +4,109 @@
 
 package dev.flutter.federated_plugin
 
-import androidx.annotation.NonNull;
+import android.Manifest
+import android.app.Activity
+import android.content.Context
+import android.content.pm.PackageManager
+import androidx.annotation.NonNull
+import androidx.core.app.ActivityCompat.requestPermissions
+import androidx.core.content.ContextCompat
+import com.google.android.gms.location.LocationServices.getFusedLocationProviderClient
 
 import io.flutter.embedding.engine.plugins.FlutterPlugin
+import io.flutter.embedding.engine.plugins.activity.ActivityAware
+import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding
 import io.flutter.plugin.common.MethodCall
 import io.flutter.plugin.common.MethodChannel
 import io.flutter.plugin.common.MethodChannel.MethodCallHandler
 import io.flutter.plugin.common.MethodChannel.Result
-import io.flutter.plugin.common.PluginRegistry.Registrar
-
-/** FederatedPlugin */
-public class FederatedPlugin: FlutterPlugin, MethodCallHandler {
-  /// The MethodChannel that will the communication between Flutter and native Android
-  ///
-  /// This local reference serves to register the plugin with the Flutter Engine and unregister it
-  /// when the Flutter Engine is detached from the Activity
-  private lateinit var channel : MethodChannel
-
-  override fun onAttachedToEngine(@NonNull flutterPluginBinding: FlutterPlugin.FlutterPluginBinding) {
-    channel = MethodChannel(flutterPluginBinding.getFlutterEngine().getDartExecutor(), "federated_plugin")
-    channel.setMethodCallHandler(this);
-  }
-
-  override fun onMethodCall(@NonNull call: MethodCall, @NonNull result: Result) {
-    if (call.method == "getPlatformVersion") {
-      result.success("Android ${android.os.Build.VERSION.RELEASE}")
-    } else {
-      result.notImplemented()
-    }
-  }
-
-  override fun onDetachedFromEngine(@NonNull binding: FlutterPlugin.FlutterPluginBinding) {
-    channel.setMethodCallHandler(null)
-  }
+import io.flutter.plugin.common.PluginRegistry
+
+
+class FederatedPlugin : FlutterPlugin, MethodCallHandler, ActivityAware, PluginRegistry.RequestPermissionsResultListener {
+    private lateinit var channel: MethodChannel
+    private lateinit var context: Context
+    private lateinit var activity: Activity
+    private lateinit var result: Result
+    private val REQUEST_CODE = 1001
+
+    override fun onAttachedToEngine(@NonNull flutterPluginBinding: FlutterPlugin.FlutterPluginBinding) {
+        channel = MethodChannel(flutterPluginBinding.binaryMessenger, "location")
+        channel.setMethodCallHandler(this)
+        context = flutterPluginBinding.applicationContext
+    }
+
+    override fun onMethodCall(@NonNull call: MethodCall, @NonNull result: Result) {
+        this.result = result
+        if (call.method == "getLocation") {
+            // Check for the runtime permission if SDK version is greater than 23. If permissions
+            // are granted, send the location data back to Dart. If permissions are not granted,
+            // request for the runtime permissions.
+            if (android.os.Build.VERSION.SDK_INT > android.os.Build.VERSION_CODES.LOLLIPOP && !checkPermissions()) {
+                requestPermissions(activity, arrayOf(
+                        Manifest.permission.ACCESS_FINE_LOCATION,
+                        Manifest.permission.ACCESS_COARSE_LOCATION
+                ), REQUEST_CODE)
+            } else {
+                provideLocation()
+            }
+        } else {
+            result.notImplemented()
+        }
+    }
+
+    // Method to fetch and send the last known location of the device to Dart.
+    private fun provideLocation() {
+        getFusedLocationProviderClient(context).lastLocation
+                .addOnSuccessListener { location ->
+                    if (location != null) {
+                        result.success(listOf(location.longitude, location.latitude))
+                    } else {
+                        result.error("NOT_DETERMINED", "Not able to determine location", null)
+                    }
+                }.addOnFailureListener { exception ->
+                    result.error("Error", exception.message, null)
+                }
+    }
+
+    // Method to check permissions to access the location data.
+    private fun checkPermissions(): Boolean {
+        val fineLocationPermission = ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION)
+        val coarseLocationPermission = ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION)
+
+        return fineLocationPermission == PackageManager.PERMISSION_GRANTED &&
+                coarseLocationPermission == PackageManager.PERMISSION_GRANTED
+    }
+
+
+    override fun onDetachedFromEngine(@NonNull binding: FlutterPlugin.FlutterPluginBinding) {
+        channel.setMethodCallHandler(null)
+    }
+
+    override fun onDetachedFromActivity() {}
+
+    override fun onReattachedToActivityForConfigChanges(binding: ActivityPluginBinding) {
+        activity = binding.activity
+    }
+
+    override fun onAttachedToActivity(binding: ActivityPluginBinding) {
+        activity = binding.activity
+        binding.addRequestPermissionsResultListener(this)
+    }
+
+    override fun onDetachedFromActivityForConfigChanges() {}
+
+    // Callback for the result after requesting for runtime permissions. If permissions
+    // are granted, send the location data, or send an error back to Dart if permissions
+    // are not granted.
+    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>?, grantResults: IntArray): Boolean {
+        if (requestCode == REQUEST_CODE && grantResults.isNotEmpty()) {
+            if (grantResults[0] == PackageManager.PERMISSION_GRANTED && grantResults[1] == PackageManager.PERMISSION_GRANTED) {
+                provideLocation()
+            } else {
+                result.error("PERMISSION_DENIED", "Permission denied from User", null)
+            }
+        }
+        return false
+    }
 }

experimental/federated_plugin/federated_plugin/example/lib/main.dart

@@ -2,60 +2,74 @@
 // 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:flutter/material.dart';
-import 'package:flutter/services.dart';
 import 'package:federated_plugin/federated_plugin.dart';
+import 'package:flutter/material.dart';
 
 void main() {
   runApp(MyApp());
 }
 
-class MyApp extends StatefulWidget {
+class MyApp extends StatelessWidget {
   @override
-  _MyAppState createState() => _MyAppState();
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      home: HomePage(),
+    );
+  }
 }
 
-class _MyAppState extends State<MyApp> {
-  String _platformVersion = 'Unknown';
-
+/// Demonstrates how to use the getLocation method from federated_plugin to access
+/// location data.
+class HomePage extends StatefulWidget {
   @override
-  void initState() {
-    super.initState();
-    initPlatformState();
-  }
-
-  // Platform messages are asynchronous, so we initialize in an async method.
-  Future<void> initPlatformState() async {
-    String platformVersion;
-    // Platform messages may fail, so we use a try/catch PlatformException.
-    try {
-      platformVersion = await FederatedPlugin.platformVersion;
-    } on PlatformException {
-      platformVersion = 'Failed to get platform version.';
-    }
+  _HomePageState createState() => _HomePageState();
+}
 
-    // If the widget was removed from the tree while the asynchronous platform
-    // message was in flight, we want to discard the reply rather than calling
-    // setState to update our non-existent appearance.
-    if (!mounted) return;
-
-    setState(() {
-      _platformVersion = platformVersion;
-    });
-  }
+class _HomePageState extends State<HomePage> {
+  Location location;
 
   @override
   Widget build(BuildContext context) {
-    return MaterialApp(
-      home: Scaffold(
-        appBar: AppBar(
-          title: const Text('Plugin example app'),
-        ),
-        body: Center(
-          child: Text('Running on: $_platformVersion\n'),
-        ),
+    return Scaffold(
+      appBar: AppBar(
+        title: Text('Federated Plugin Demo'),
+      ),
+      body: Builder(
+        builder: (context) {
+          return Center(
+            child: Column(
+              mainAxisAlignment: MainAxisAlignment.center,
+              children: [
+                location == null
+                    ? SizedBox.shrink()
+                    : Text(
+                        'Latitude: ${location.latitude}\n'
+                        'Longitude: ${location.longitude}',
+                        style: Theme.of(context).textTheme.headline5,
+                      ),
+                SizedBox(height: 16),
+                RaisedButton(
+                  child: Text('Get Location'),
+                  onPressed: () async {
+                    try {
+                      final result = await getLocation();
+                      setState(() {
+                        location = result;
+                      });
+                    } catch (error) {
+                      Scaffold.of(context).showSnackBar(
+                        SnackBar(
+                          backgroundColor: Theme.of(context).primaryColor,
+                          content: Text(error.message as String),
+                        ),
+                      );
+                    }
+                  },
+                ),
+              ],
+            ),
+          );
+        },
       ),
     );
   }

experimental/federated_plugin/federated_plugin/example/pubspec.lock

@@ -64,6 +64,13 @@ packages:
       relative: true
     source: path
     version: "0.0.1"
+  federated_plugin_platform_interface:
+    dependency: transitive
+    description:
+      path: "../../federated_plugin_platform_interface"
+      relative: true
+    source: path
+    version: "0.0.1"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -102,6 +109,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.9.2"
+  plugin_platform_interface:
+    dependency: transitive
+    description:
+      name: plugin_platform_interface
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.2"
   sky_engine:
     dependency: transitive
     description: flutter

experimental/federated_plugin/federated_plugin/example/test/widget_test.dart

@@ -2,23 +2,35 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'package:federated_plugin/federated_plugin.dart';
+import 'package:federated_plugin_example/main.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 
-import 'package:federated_plugin_example/main.dart';
-
 void main() {
-  testWidgets('Verify Platform version', (tester) async {
-    // Build our app and trigger a frame.
-    await tester.pumpWidget(MyApp());
+  group('federated plugin demo tests', () {
+    final location = Location(latitude: 131.0, longitude: 221.0);
+    setUpAll(() {
+      MethodChannel('location').setMockMethodCallHandler((call) async {
+        if (call.method == 'getLocation') {
+          return [location.longitude, location.latitude];
+        }
+      });
+    });
+
+    testWidgets('get location from platform', (tester) async {
+      await tester.pumpWidget(MyApp());
+
+      // Tap button to get location from platform.
+      await tester.tap(find.byType(RaisedButton));
+      await tester.pumpAndSettle();
 
-    // Verify that platform version is retrieved.
-    expect(
-      find.byWidgetPredicate(
-        (widget) => widget is Text &&
-                           widget.data.startsWith('Running on:'),
-      ),
-      findsOneWidget,
-    );
+      expect(
+        find.text('Latitude: ${location.latitude}\n'
+            'Longitude: ${location.longitude}'),
+        findsOneWidget,
+      );
+    });
   });
 }

experimental/federated_plugin/federated_plugin/lib/federated_plugin.dart

@@ -4,13 +4,13 @@
 
 import 'dart:async';
 
-import 'package:flutter/services.dart';
+import 'package:federated_plugin_platform_interface/federated_plugin_platform_interface.dart';
+import 'package:federated_plugin_platform_interface/location_model.dart';
+export 'package:federated_plugin_platform_interface/location_model.dart';
 
-class FederatedPlugin {
-  static const MethodChannel _channel = MethodChannel('federated_plugin');
-
-  static Future<String> get platformVersion async {
-    final version = await _channel.invokeMethod<String>('getPlatformVersion');
-    return version;
-  }
+/// Returns [Location] to provide latitude and longitude.
+///
+/// It uses [FederatedPluginInterface] interface to provide location.
+Future<Location> getLocation() async {
+  return await FederatedPluginInterface.instance.getLocation();
 }

experimental/federated_plugin/federated_plugin/pubspec.lock

@@ -50,6 +50,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.1.0"
+  federated_plugin_platform_interface:
+    dependency: "direct main"
+    description:
+      path: "../federated_plugin_platform_interface"
+      relative: true
+    source: path
+    version: "0.0.1"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -88,6 +95,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.9.2"
+  plugin_platform_interface:
+    dependency: transitive
+    description:
+      name: plugin_platform_interface
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.2"
   sky_engine:
     dependency: transitive
     description: flutter

experimental/federated_plugin/federated_plugin/pubspec.yaml

@@ -12,6 +12,8 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
+  federated_plugin_platform_interface:
+    path: ../federated_plugin_platform_interface
 
 dev_dependencies:
   flutter_test:

experimental/federated_plugin/federated_plugin/test/federated_plugin_test.dart

@@ -7,21 +7,20 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:federated_plugin/federated_plugin.dart';
 
 void main() {
-  const channel = MethodChannel('federated_plugin');
-
   TestWidgetsFlutterBinding.ensureInitialized();
 
-  setUp(() {
-    channel.setMockMethodCallHandler((methodCall) async {
-      return '42';
+  group('Federated Plugin Test', () {
+    final location = Location(latitude: 131.0, longitude: 221.0);
+    MethodChannel('location').setMockMethodCallHandler((call) async {
+      if (call.method == 'getLocation') {
+        return [location.longitude, location.latitude];
+      }
     });
-  });
 
-  tearDown(() {
-    channel.setMockMethodCallHandler(null);
-  });
-
-  test('getPlatformVersion', () async {
-    expect(await FederatedPlugin.platformVersion, '42');
+    test('getLocation method test', () async {
+      final result = await getLocation();
+      expect(result.longitude, location.longitude);
+      expect(result.latitude, location.latitude);
+    });
   });
 }

experimental/federated_plugin/federated_plugin_platform_interface/.gitignore

@@ -0,0 +1,75 @@
+# Miscellaneous
+*.class
+*.log
+*.pyc
+*.swp
+.DS_Store
+.atom/
+.buildlog/
+.history
+.svn/
+
+# IntelliJ related
+*.iml
+*.ipr
+*.iws
+.idea/
+
+# The .vscode folder contains launch configuration and tasks you configure in
+# VS Code which you may wish to be included in version control, so this line
+# is commented out by default.
+#.vscode/
+
+# Flutter/Dart/Pub related
+**/doc/api/
+.dart_tool/
+.flutter-plugins
+.flutter-plugins-dependencies
+.packages
+.pub-cache/
+.pub/
+build/
+
+# Android related
+**/android/**/gradle-wrapper.jar
+**/android/.gradle
+**/android/captures/
+**/android/gradlew
+**/android/gradlew.bat
+**/android/local.properties
+**/android/**/GeneratedPluginRegistrant.java
+
+# iOS/XCode related
+**/ios/**/*.mode1v3
+**/ios/**/*.mode2v3
+**/ios/**/*.moved-aside
+**/ios/**/*.pbxuser
+**/ios/**/*.perspectivev3
+**/ios/**/*sync/
+**/ios/**/.sconsign.dblite
+**/ios/**/.tags*
+**/ios/**/.vagrant/
+**/ios/**/DerivedData/
+**/ios/**/Icon?
+**/ios/**/Pods/
+**/ios/**/.symlinks/
+**/ios/**/profile
+**/ios/**/xcuserdata
+**/ios/.generated/
+**/ios/Flutter/App.framework
+**/ios/Flutter/Flutter.framework
+**/ios/Flutter/Flutter.podspec
+**/ios/Flutter/Generated.xcconfig
+**/ios/Flutter/app.flx
+**/ios/Flutter/app.zip
+**/ios/Flutter/flutter_assets/
+**/ios/Flutter/flutter_export_environment.sh
+**/ios/ServiceDefinitions.json
+**/ios/Runner/GeneratedPluginRegistrant.*
+
+# Exceptions to above rules.
+!**/ios/**/default.mode1v3
+!**/ios/**/default.mode2v3
+!**/ios/**/default.pbxuser
+!**/ios/**/default.perspectivev3
+!/packages/flutter_tools/test/data/dart_dependencies_test/**/.packages

experimental/federated_plugin/federated_plugin_platform_interface/.metadata

@@ -0,0 +1,10 @@
+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: 8bd2e6585b0eda5ccdc10c1e1d35105e11f84424
+  channel: master
+
+project_type: package

experimental/federated_plugin/federated_plugin_platform_interface/analysis_options.yaml

@@ -0,0 +1,31 @@
+include: package:pedantic/analysis_options.yaml
+
+analyzer:
+  strong-mode:
+    implicit-casts: false
+    implicit-dynamic: false
+
+linter:
+  rules:
+    - avoid_types_on_closure_parameters
+    - avoid_void_async
+    - await_only_futures
+    - camel_case_types
+    - cancel_subscriptions
+    - close_sinks
+    - constant_identifier_names
+    - control_flow_in_finally
+    - directives_ordering
+    - empty_statements
+    - hash_and_equals
+    - implementation_imports
+    - non_constant_identifier_names
+    - package_api_docs
+    - package_names
+    - package_prefixed_library_names
+    - test_types_in_equals
+    - throw_in_finally
+    - unnecessary_brace_in_string_interps
+    - unnecessary_getters_setters
+    - unnecessary_new
+    - unnecessary_statements

experimental/federated_plugin/federated_plugin_platform_interface/lib/federated_plugin_platform_interface.dart

@@ -0,0 +1,31 @@
+// Copyright 2020 The Flutter team. 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:federated_plugin_platform_interface/location_method_channel.dart';
+import 'package:federated_plugin_platform_interface/location_model.dart';
+import 'package:plugin_platform_interface/plugin_platform_interface.dart';
+
+/// Interface which allows all the platform plugins to implement the same
+/// functionality.
+abstract class FederatedPluginInterface extends PlatformInterface {
+  FederatedPluginInterface() : super(token: _object);
+
+  static FederatedPluginInterface _federatedPluginInterface =
+      LocationMethodChannel();
+
+  static final Object _object = Object();
+
+  /// Provides instance of [LocationMethodChannel] to invoke platform calls.
+  static FederatedPluginInterface get instance => _federatedPluginInterface;
+
+  static set instance(FederatedPluginInterface instance) {
+    PlatformInterface.verifyToken(instance, _object);
+    _federatedPluginInterface = instance;
+  }
+
+  /// Returns [Location] to provide latitude and longitude.
+  Future<Location> getLocation() async {
+    throw UnimplementedError('getLocation() has not been implemented.');
+  }
+}

experimental/federated_plugin/federated_plugin_platform_interface/lib/location_method_channel.dart

@@ -0,0 +1,24 @@
+// Copyright 2020 The Flutter team. 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:federated_plugin_platform_interface/federated_plugin_platform_interface.dart';
+import 'package:federated_plugin_platform_interface/location_model.dart';
+import 'package:flutter/services.dart';
+
+/// Implements [FederatedPluginInterface] using [MethodChannel] to fetch
+/// location from platform.
+class LocationMethodChannel extends FederatedPluginInterface {
+  static const MethodChannel _methodChannel = MethodChannel('location');
+
+  @override
+  Future<Location> getLocation() async {
+    final result =
+        await _methodChannel.invokeMethod<List<dynamic>>('getLocation');
+
+    return Location(
+      longitude: result.first as double,
+      latitude: result.last as double,
+    );
+  }
+}

experimental/federated_plugin/federated_plugin_platform_interface/lib/location_model.dart

@@ -0,0 +1,11 @@
+// Copyright 2020 The Flutter team. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/// Model to hold the incoming latitude and longitude values from platform.
+class Location {
+  final double latitude;
+  final double longitude;
+
+  Location({this.latitude, this.longitude});
+}

experimental/federated_plugin/federated_plugin_platform_interface/pubspec.lock

@@ -0,0 +1,161 @@
+# Generated by pub
+# See https://dart.dev/tools/pub/glossary#lockfile
+packages:
+  async:
+    dependency: transitive
+    description:
+      name: async
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.4.2"
+  boolean_selector:
+    dependency: transitive
+    description:
+      name: boolean_selector
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.0"
+  characters:
+    dependency: transitive
+    description:
+      name: characters
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0-nullsafety"
+  charcode:
+    dependency: transitive
+    description:
+      name: charcode
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.3"
+  clock:
+    dependency: transitive
+    description:
+      name: clock
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.1"
+  collection:
+    dependency: transitive
+    description:
+      name: collection
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.15.0-nullsafety"
+  fake_async:
+    dependency: transitive
+    description:
+      name: fake_async
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0"
+  flutter:
+    dependency: "direct main"
+    description: flutter
+    source: sdk
+    version: "0.0.0"
+  flutter_test:
+    dependency: "direct dev"
+    description: flutter
+    source: sdk
+    version: "0.0.0"
+  matcher:
+    dependency: transitive
+    description:
+      name: matcher
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.12.8"
+  meta:
+    dependency: transitive
+    description:
+      name: meta
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.3.0-nullsafety"
+  path:
+    dependency: transitive
+    description:
+      name: path
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.7.0"
+  pedantic:
+    dependency: "direct dev"
+    description:
+      name: pedantic
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.9.2"
+  plugin_platform_interface:
+    dependency: "direct main"
+    description:
+      name: plugin_platform_interface
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.2"
+  sky_engine:
+    dependency: transitive
+    description: flutter
+    source: sdk
+    version: "0.0.99"
+  source_span:
+    dependency: transitive
+    description:
+      name: source_span
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.7.0"
+  stack_trace:
+    dependency: transitive
+    description:
+      name: stack_trace
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.9.5"
+  stream_channel:
+    dependency: transitive
+    description:
+      name: stream_channel
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.0"
+  string_scanner:
+    dependency: transitive
+    description:
+      name: string_scanner
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.5"
+  term_glyph:
+    dependency: transitive
+    description:
+      name: term_glyph
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0"
+  test_api:
+    dependency: transitive
+    description:
+      name: test_api
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.2.17"
+  typed_data:
+    dependency: transitive
+    description:
+      name: typed_data
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.3.0-nullsafety"
+  vector_math:
+    dependency: transitive
+    description:
+      name: vector_math
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.1.0-nullsafety"
+sdks:
+  dart: ">=2.9.0-18.0 <2.9.0"
+  flutter: ">=1.17.0 <2.0.0"

experimental/federated_plugin/federated_plugin_platform_interface/pubspec.yaml

@@ -0,0 +1,20 @@
+name: federated_plugin_platform_interface
+description: A new Flutter package project.
+version: 0.0.1
+author:
+homepage:
+publish_to: none
+
+environment:
+  sdk: ">=2.7.0 <3.0.0"
+  flutter: ">=1.17.0 <2.0.0"
+
+dependencies:
+  flutter:
+    sdk: flutter
+  plugin_platform_interface: ^1.0.2
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+  pedantic: ^1.9.0

experimental/federated_plugin/federated_plugin_platform_interface/test/federated_plugin_platform_interface_test.dart

@@ -0,0 +1,28 @@
+// Copyright 2020 The Flutter team. 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:federated_plugin_platform_interface/location_method_channel.dart';
+import 'package:federated_plugin_platform_interface/location_model.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
+  group('MethodChannel test', () {
+    final location = Location(latitude: 1.0, longitude: 2.0);
+    MethodChannel('location').setMockMethodCallHandler((call) async {
+      if (call.method == 'getLocation') {
+        return [location.longitude, location.latitude];
+      }
+    });
+
+    test('getLocation method test', () async {
+      final locationMethodChannel = LocationMethodChannel();
+      final result = await locationMethodChannel.getLocation();
+      expect(result.longitude, location.longitude);
+      expect(result.latitude, result.latitude);
+    });
+  });
+}