create-test

name	create-test
description	Process for creating unit and widget tests in the test/ directory mirroring the lib/src/ directory structure. Covers using Mockito.

Testing Skill

This skill defines the process for writing and running unit and widget tests in the project.

1. Directory Structure

Test files must mirror the lib/src/ directory hierarchy under test/:

lib/src/
└── infrastructure/
    └── auth/
        └── auth_repository.dart

test/src/
└── infrastructure/
    └── auth/
        └── auth_repository_test.dart

All test files must end with the _test.dart suffix.

2. Mocking Guidelines

• Mocking Tool: Use the mockito package for mocking infrastructure and external client dependencies.
• Generator: Annotate test files with @GenerateMocks to auto-generate mocks using build_runner.

2.1 Generating Mocks Example

Annotate your test file's main() method with the dependencies to mock:

import 'package:apple_project/src/infrastructure/auth/auth_repository.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:mockito/annotations.dart';
import 'package:mockito/mockito.dart';

// Import the generated mock file (ends with .mocks.dart)
import 'auth_repository_test.mocks.dart';

@GenerateMocks([AuthRepository])
void main() {
  // Test code goes here
}

To build/generate the mock implementation, run:

melos run generate

3. Writing Unit Tests

Structure tests logically using group, test, and standard Mockito APIs:

void main() {
  late MockAuthRepository mockAuthRepo;

  setUp(() {
    mockAuthRepo = MockAuthRepository();
  });

  group('AuthRepository Tests', () {
    test('login returns success on correct credentials', () async {
      // Arrange
      when(mockAuthRepo.login('user', 'pass'))
          .thenAnswer((_) async => const Ok(null));

      // Act
      final result = await mockAuthRepo.login('user', 'pass');

      // Assert
      expect(result.isOk, isTrue);
      verify(mockAuthRepo.login('user', 'pass')).called(1);
    });
  });
}

4. Running Tests

• Run all unit and widget tests:

  flutter test
  

• Run tests for a specific test file:

  flutter test test/src/infrastructure/auth/auth_repository_test.dart