Flutter test generator (Flutter Test Gen)

A CLI tool to automatically generate unit tests for Flutter and Dart projects.

flutter_test_gen analyzes Dart files and generates structured test templates, helping developers quickly start writing tests without manually creating boilerplate code.

Features

• Generate tests for classes and top-level functions
• Automatically create the correct test/ folder structure
• Append missing tests to existing test files
• Restore deleted tests inside groups
• Restore deleted groups
• Prevent duplicate test generation
• Supports:
  • async methods
  • static methods
• Adds tags to each test
• Skips:
  • private methods
  • mixins
  • extensions
• CLI help command

Installation

Add the package to your project:

dev_dependencies:
  flutter_test_gen: ^0.0.1
  mocktail: ^1.0.0 # only when you need to mock dependencies

Then run:

dart pub get

Usage

Generate tests for a Dart file:

dart run flutter_test_gen generate user_service

You can also specify a full file path:

dart run flutter_test_gen generate lib/services/user_service.dart

For convenience, the command also works without generate:

dart run flutter_test_gen user_service

CLI Commands

Generate tests

dart run flutter_test_gen generate <FILE_NAME>

Default behavior is append missing tests.

Append missing tests

dart run flutter_test_gen generate <FILE_NAME> --append

Adds only tests that do not already exist.

Overwrite existing tests

dart run flutter_test_gen generate <FILE_NAME> --overwrite

Recreates the test file completely.

Show help

dart run flutter_test_gen --help

Example

Source file

class UserService {
  int getAge() {
    return 30;
  }

  static int add(int a, int b) {
    return a + b;
  }
}

Generated test

group('UserService | lib/user_service.dart', () {
  late UserService service;

  setUp(() {
    service = UserService();
  });

  test('getAge', () {
    // Arrange

    // Act
    final result = service.getAge();

    // Assert
    expect(result, isNotNull);
  });

  test('add', () {
    // Arrange

    // Act
    final result = UserService.add(1, 1);

    // Assert
    expect(result, isNotNull);
  });
});

Behavior

The generator:

• Creates test files inside the test/ directory
• Groups tests by class name
• Restores deleted tests if they are removed
• Restores deleted groups if they are removed
• Prevents duplicate test generation
• Does not modify existing test structure

Requirements

• Dart SDK
• Flutter project (recommended)

Quick Demo

Generate tests for a service:

dart run flutter_test_gen generate user_service

Output:

✓ Found Dart file
✓ Parsed methods
✓ Generated test templates
✓ Appended missing tests

Project Structure

flutter_test_gen
 ├── bin/
 │   └── flutter_test_gen.dart
 ├── lib/
 │   ├── flutter_test_gen.dart
 │   └── src/
 │       ├── generator/
 │       ├── parser/
 │       ├── models/
 │       └── utils/
 ├── example/
 ├── test/
 ├── README.md
 ├── LICENSE
 └── pubspec.yaml

Roadmap

Planned improvements:

• smarter test data generation
• automatic mock generation
• test coverage integration
• watch mode for automatic test generation

Contributing

Contributions are welcome.

1. Fork the repository
2. Create a feature branch
3. Commit your changes
4. Open a pull request

License

MIT License

Repository

github.com/braglath/flutter_test_gen

Author

Built by Flutter Zone to make Flutter unit testing faster and easier.

Keywords

Flutter test generator
Dart test generator
Flutter unit test automation
Flutter testing CLI tool