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
• Generate tests for all Dart files inside a directory (recursive)
• Automatically create the correct test/ folder structure
• Append missing tests to existing test files (default)
• Overwrite existing tests when needed
• 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
• Clean and structured CLI output
• CLI help and debug support

Installation

Add the package using:

flutter pub add flutter_test_gen --dev

This will install the latest version from pub.dev automatically.

If your code uses dependencies, you may also need:

flutter pub add mocktail --dev

Usage

Generate for a single file

dart run flutter_test_gen user_service

Generate using full path

dart run flutter_test_gen lib/services/user_service.dart

Generate for all files in a folder

dart run flutter_test_gen lib/utils

Append missing tests

dart run flutter_test_gen <FILE_NAME> --append

Adds only tests that do not already exist.

Overwrite existing tests

dart run flutter_test_gen <FILE_NAME> --overwrite

Recreates the test file completely.

Show help

dart run flutter_test_gen --help

Example

Input

class UserService { int getAge() => 30; }

Generated test

group('UserService', () {
  late UserService service;

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

  test('getAge', () {
    final result = service.getAge();
    expect(result, isNotNull);
  });
});

Behavior

The generator:

• Supports both files and directories
• Recursively scans folders for Dart files
• Creates test files inside the test/ directory
• Groups tests by class name
• Restores deleted tests and groups
• Prevents duplicate test generation
• Does not modify existing test structure unnecessarily

Requirements

• Dart SDK
• Flutter project (recommended)

Quick Demo

Generate tests for a folder:

dart run flutter_test_gen lob/utils

Output:

📂 lib/utils

→ string_utils.dart

✓ test/utils/string_utils_test.dart

→ math_utils.dart

⚙ mocks

✓ test/utils/math_utils_test.dart

✓ 2 files processed

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