flutter/packages/flutter_web_plugins/test/plugin_registry_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.

@TestOn('chrome') // Uses web-only Flutter SDK

import 'dart:ui' as ui; // ignore: unused_import, it looks unused as web-only elements are the only elements used.

import 'package:flutter/services.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:flutter_web_plugins/flutter_web_plugins.dart';

class TestPlugin {
  static void registerWith(Registrar registrar) {
    final MethodChannel channel = MethodChannel(
      'test_plugin',
      const StandardMethodCodec(),
      registrar.messenger,
    );
    final TestPlugin testPlugin = TestPlugin();
    channel.setMethodCallHandler(testPlugin.handleMethodCall);
  }

  static final List<String> calledMethods = <String>[];

  Future<void> handleMethodCall(MethodCall call) async {
    calledMethods.add(call.method);
  }
}

void main() {
  // Disabling tester emulation because this test relies on real message channel communication.
  ui.debugEmulateFlutterTesterEnvironment = false; // ignore: undefined_prefixed_name

  group('Plugin Registry', () {
    setUp(() {
      TestWidgetsFlutterBinding.ensureInitialized();
      webPluginRegistry.registerMessageHandler();
      final Registrar registrar = webPluginRegistry.registrarFor(TestPlugin);
      TestPlugin.registerWith(registrar);
    });

    test('can register a plugin', () {
      TestPlugin.calledMethods.clear();

      const MethodChannel frameworkChannel =
          MethodChannel('test_plugin', StandardMethodCodec());
      frameworkChannel.invokeMethod<void>('test1');

      expect(TestPlugin.calledMethods, equals(<String>['test1']));
    });

    test('can send a message from the plugin to the framework', () async {
      const StandardMessageCodec codec = StandardMessageCodec();

      final List<String> loggedMessages = <String>[];
      ServicesBinding.instance!.defaultBinaryMessenger
          .setMessageHandler('test_send', (ByteData? data) {
        loggedMessages.add(codec.decodeMessage(data) as String);
        return Future<ByteData?>.value(null);
      });

      await pluginBinaryMessenger.send(
          'test_send', codec.encodeMessage('hello'));
      expect(loggedMessages, equals(<String>['hello']));

      await pluginBinaryMessenger.send(
          'test_send', codec.encodeMessage('world'));
      expect(loggedMessages, equals(<String>['hello', 'world']));

      ServicesBinding.instance!.defaultBinaryMessenger
          .setMessageHandler('test_send', null);
    });

    test('throws when trying to set a mock handler', () {
      expect(
          () => pluginBinaryMessenger.setMockMessageHandler(
              'test', (ByteData? data) async => ByteData(0)),
          throwsFlutterError);
    });
  });
}