halkyon/packages/halkyon_app/test/speech/voice_input_app_test.dart

import 'package:flutter/foundation.dart';
import 'package:flutter/services.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:halkyon_app/halkyon_app.dart';

/// The device's voice input app through Android's `RECOGNIZE_SPEECH`
/// intent (Halkyon Meditate's ADR 0038, D18), asked through each app's
/// `VoiceInput.kt` on `app.halkyon/voice_input`, its channel answering as
/// the activity does.
void main() {
  TestWidgetsFlutterBinding.ensureInitialized();
  late List<MethodCall> calls;

  void answer(Object? Function(MethodCall call) answers) {
    calls = [];
    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
        .setMockMethodCallHandler(ChannelVoiceInputApp.channel, (call) async {
          calls.add(call);
          return answers(call);
        });
  }

  tearDown(() {
    debugDefaultTargetPlatformOverride = null;
    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
        .setMockMethodCallHandler(ChannelVoiceInputApp.channel, null);
  });

  const app = ChannelVoiceInputApp();

  group('installed', () {
    test('where Android has an app for the intent', () async {
      answer((call) => call.method == 'installed');
      expect(await app.installed(), isTrue);
    });

    test('not where it has none', () async {
      answer((call) => false);
      expect(await app.installed(), isFalse);
    });

    test('not where the activity fails or knows no such channel', () async {
      answer((call) => throw PlatformException(code: 'failed'));
      expect(await app.installed(), isFalse);
      TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
          .setMockMethodCallHandler(ChannelVoiceInputApp.channel, null);
      expect(await app.installed(), isFalse);
    });

    test('never off Android, without asking', () async {
      answer((call) => true);
      for (final platform in [
        TargetPlatform.iOS,
        TargetPlatform.linux,
        TargetPlatform.macOS,
        TargetPlatform.windows,
      ]) {
        debugDefaultTargetPlatformOverride = platform;
        expect(await app.installed(), isFalse, reason: '$platform');
      }
      expect(calls, isEmpty);
    });
  });

  group('listening', () {
    test('asks in the language given, with the prompt, and hands back the '
        'words', () async {
      answer((call) => 'a house by the sea');
      expect(
        await app.listen(language: 'de-DE', prompt: 'Was hast du geträumt?'),
        'a house by the sea',
      );
      final listen = calls.single;
      expect(listen.method, 'listen');
      expect(listen.arguments, {
        'language': 'de-DE',
        'prompt': 'Was hast du geträumt?',
      });
    });

    test('cancelled, hands back nothing', () async {
      answer((call) => '');
      expect(await app.listen(language: null), '');
      expect(calls.single.arguments, {'language': null, 'prompt': null});
    });

    test(
      'where the app could not be opened, says so without throwing',
      () async {
        answer((call) => throw PlatformException(code: 'noApp'));
        expect(await app.listen(language: 'en'), isNull);
        TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
            .setMockMethodCallHandler(ChannelVoiceInputApp.channel, null);
        expect(await app.listen(language: 'en'), isNull);
      },
    );
  });
}