g_tester #

g_tester is a command-line tool that automatically generates Dart/Flutter unit test files from your project's lib/ structure. It supports both basic test skeletons and AI-powered test generation using Gemini for business logic, services, and utility classes.

Features #

• Automatic Unit Test Generation: Analyzes your Dart classes and generates comprehensive unit test files
• Class Analysis: Identifies class constructors, methods, async operations, and exception handling
• Method Testing: Automatically generates tests for various method types and callbacks
• AI-Powered Generation: Optional AI enhancement using Google's Gemini for more comprehensive tests
• Cross-Platform: Works on Linux, Windows, and macOS
• Multiple Directory Support: Automatically processes classes in /domain/, /data/, /core/, /utils/, and /presentation/ directories

Installation #

dart pub global activate g_tester

Usage #

Generate Basic Unit Test Skeletons #

g_tester --unit
# or shorter:
g_tester -u

Generate AI-Enhanced Tests #

# Use default model
g_tester --ai "YOUR_GEMINI_API_KEY"

# Use specific model
g_tester --ai "gemini-2.5-pro:YOUR_GEMINI_API_KEY"

Check Available Models #

g_tester --check "YOUR_GEMINI_API_KEY"

Check Version #

g_tester --version
# or shorter:
g_tester -v

Get Help #

g_tester --help
# or shorter:
g_tester -h

How It Works #

g_tester scans your lib/ directory (specifically files in /domain/, /data/, /core/, /utils/, and /presentation/ subdirectories) and:

1. Analyzes your classes to identify:

   • Class constructors and parameters
   • Method signatures and return types
   • Async methods (Future-returning)
   • Stream methods
   • Exception handling patterns

2. Generates unit test files in the test/ directory that include:

   • Basic instantiation tests
   • Method calling tests
   • Async operation tests
   • Exception handling tests
   • Proper import statements using the test package

Example #

Given a service class like:

class UserService {
  final String baseUrl;

  UserService(this.baseUrl);

  Future<User> getUser(int id) async {
    // Fetch user from API
  }

  void validateUser(User user) {
    if (user.name.isEmpty) {
      throw ArgumentError('User name cannot be empty');
    }
  }
}

g_tester generates:

import 'package:test/test.dart';
import 'package:your_app/data/user_service.dart';

void main() {
  group('UserService', () {
    test('can be instantiated', () {
      final userservice = UserService('https://api.example.com');
      expect(userservice, isNotNull);
    });

    test('handles baseUrl parameter', () {
      // TODO: Test with baseUrl parameter of type String
      // final instance = UserService(baseUrl: 'https://api.example.com');
      // expect(instance.baseUrl, 'https://api.example.com');
    });

    test('handles async operations', () async {
      final userservice = UserService('https://api.example.com');
      // TODO: Test async method functionality
      // await userservice.getUser(123);
      // expect(...);
    });

    test('handles exceptions properly', () {
      final userservice = UserService('https://api.example.com');
      // TODO: Test exception handling
      // expect(() => userservice.validateUser(InvalidUser()), throwsException);
    });
  });
}

Configuration #

g_tester automatically processes all .dart files in these directories while ignoring:

• Generated files (.g.dart, .freezed.dart)
• Test files (_test.dart)
• main.dart
• Files outside supported directories

Requirements #

• Dart SDK: >=3.0.0 <4.0.0

Contributing #

Feel free to submit issues and enhancement requests in the Issues Tracker.

License #

This project is licensed under the MIT License - see the LICENSE file for details.