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🧑‍💻 First test

Create e2e_test.dart file in the test folder. E2E means End-to-End. Together, step by step, we'll craft a comprehensive test that validates entire user journey.

test/e2e_test.dart
// ‼️ Replace 'your_app' with your app package
import 'package:your_app/main.dart';
import 'package:taptest/taptest.dart';

void main() {
  final config = Config(
    builder: (params) {
      return MyApp();
    },
  );

  tapTest('My E2E Widget test', config, (tt) async {
    // 🎪 The magic happens here - coming up next!
  });
}

⚠️ Important: All test files must end with _test.dart - Flutter's testing convention!

Run test with the command as follows:

flutter test test

💡 test test? First test is a command like build, test, run. Second test indicates a folder. Above command will run all tests buried in the test directory. To run a specific test, run flutter test test/e2e_test.dart.

This test doesn't do anything meaningful yet, but we'll change that very soon! The initial run may take a few seconds for compilation, but feel free to run the command again and it should complete under 1 second.

🔑 Keys​

In TapTest, we identify and interact with widgets using keys - think of them as unique IDs for every interactive or inspectable element. Create a file app_keys.dart in the lib folder:

lib/app_keys.dart
import 'package:flutter/material.dart';

abstract class AppKeys {
  static const homeScreen = ValueKey('HomeScreen');
  // more keys coming soon
}

🏗️ Scaling Strategy: As your app grows, organize keys by feature (AuthKeys, ProfileKeys, OnboardingKeys) - but for now, one file is perfect!

Update your main.dart to import this file and assign the created key:

lib/main.dart
import 'app_keys.dart'; // 👈 here
// other imports

Widget build(BuildContext context) {
  return Scaffold(
    key: AppKeys.homeScreen, // 👈 and here in HomeScreen widget
    appBar: AppBar(title: Text('Welcome')),

🔬 First assertion​

Update your test to perform its first check:

test/e2e_test.dart
import 'package:your_app/app_keys.dart'; // 👈 import app_keys.dart

...

tapTest('My E2E Widget test', config, (tt) async {
  await tt.exists(AppKeys.homeScreen);
});

Run it: flutter test test, expected output:

My E2E Widget test
✅ HomeScreen exists
00:01 +1: All tests passed!

Notice how TapTest only knows about the HomeScreen's key - it doesn't care about your internal implementation or state management. By importing just the keys, TapTest interacts with a thin layer of your app's public interface, making tests resilient to refactoring and focused on user-visible behavior!

🎉 Achievement Unlocked!​

You've just verified your app starts correctly. Don't worry that you can't witness it executing - that's totally normal! Widget tests run invisibly, but with snapshots (soon) you can capture the output.

📚 Next steps​