Documenting unit tests is crucial for understanding the purpose of each test, how it relates to the code being tested, and ensuring future maintainers can quickly grasp what each test is meant to do.
void main() {
final getIt = GetIt.instance;
late RemoteDataSource remoteDataSource;
late ApiServiceClient apiServiceClient;
setUp(() {
Dio dio = Dio();
getIt.reset();
apiServiceClient = ApiServiceClient(dio);
getIt.registerLazySingleton<ApiServiceClient>(() => apiServiceClient);
remoteDataSource = RemoteDataSourceImp(getIt<ApiServiceClient>());
});
test('should return UserResponse when login is successful', () async {
// Arrange
final loginRequest = LoginRequest(
username: '1', password: '2', expiresInMins: 60);
final expectedResponse = LoginResponse(
id: 1,
username: 'emilys',
email: '[email protected]',
firstName: 'Emily',
lastName: 'Johnson',
gender: 'female',
image: 'https://dummyjson.com/icon/emilys/128',
token:
'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MSwidXNlcm5hbWUiOiJlbWlseXMiLCJlbWFpbCI6ImVtaWx5LmpvaG5zb25AeC5kdW1teWpzb24uY29tIiwiZmlyc3ROYW1lIjoiRW1pbHkiLCJsYXN0TmFtZSI6IkpvaG5zb24iLCJnZW5kZXIiOiJmZW1hbGUiLCJpbWFnZSI6Imh0dHBzOi8vZHVtbXlqc29uLmNvbS9pY29uL2VtaWx5cy8xMjgiLCJpYXQiOjE3MjY2NTE2ODUsImV4cCI6MTcyNjY1NTI4NX0.f03SSbNY5VhTgiKL8x-fwc51wApVhYJb64nOg9SB37k',
refreshToken:
'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MSwidXNlcm5hbWUiOiJlbWlseXMiLCJlbWFpbCI6ImVtaWx5LmpvaG5zb25AeC5kdW1teWpzb24uY29tIiwiZmlyc3ROYW1lIjoiRW1pbHkiLCJsYXN0TmFtZSI6IkpvaG5zb24iLCJnZW5kZXIiOiJmZW1hbGUiLCJpbWFnZSI6Imh0dHBzOi8vZHVtbXlqc29uLmNvbS9pY29uL2VtaWx5cy8xMjgiLCJpYXQiOjE3MjY2NTExNTMsImV4cCI6MTcyOTI0MzE1M30.6y9klhQAo5V5ELR5MsFHXWrRowcT7kNtyA_TI6E7dvs');
try {
final result = await remoteDataSource.login(loginRequest);
expect(result.id, 1);
} on DioException catch (e) {
fail('Expected a Dio Exception: $e');
} catch (e) {
fail('Expected a error but got a different exception: $e');
}
});
test('should throw an exception if login fails', () async {
final loginRequest = LoginRequest(
username: 'emilys', password: 'emilyspass', expiresInMins: 60);
try {
await remoteDataSource.login(loginRequest);
fail('Expected a error with status code 400 but got a success.');
} on DioException catch (e) {
expect(e.response?.statusCode, equals(400));
} catch (e) {
fail('Expected a error but got a different exception: $e');
}
});
} Overview of the Test Suite
This test suite is designed to verify the behavior of the RemoteDataSource class, specifically focusing on the login method. The tests ensure that the login functionality behaves as expected when provided with valid and invalid credentials, including handling success and failure scenarios.
Key Components Tested:
Environment Setup
Before each test, the environment is set up using the setUp method to ensure that:
Dio is created.GetIt.RemoteDataSourceImp is initialized with the required dependencies.setUp(() {
Dio dio = Dio();
getIt.reset();
apiServiceClient = ApiServiceClient(dio);
getIt.registerLazySingleton<ApiServiceClient>(() => apiServiceClient);
remoteDataSource = RemoteDataSourceImp(getIt<ApiServiceClient>());
});This setup ensures that each test runs in isolation with a fresh state, preventing side effects from other tests. The GetIt service locator is reset to avoid conflicts between tests.
Test Case 1: Successful Login
Test Name:should return UserResponse when login is successful
Purpose:
This test verifies that when valid credentials are provided, the login method successfully returns a UserResponse object with the correct user details.
Steps:
LoginRequest with valid credentials.login method on RemoteDataSource.UserResponse contains the expected user ID and other details.test('should return UserResponse when login is successful', () async {
final loginRequest = LoginRequest(
username: '1', password: '2', expiresInMins: 60);
final expectedResponse = LoginResponse(
id: 1,
username: 'emilys',
email: '[email protected]',
firstName: 'Emily',
lastName: 'Johnson',
gender: 'female',
image: 'https://dummyjson.com/icon/emilys/128',
token: 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...',
refreshToken: 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...');
try {
final result = await remoteDataSource.login(loginRequest);
expect(result.id, 1);
} on DioException catch (e) {
fail('Expected a Dio Exception: $e');
} catch (e) {
fail('Expected a error but got a different exception: $e');
}
});This test is crucial for ensuring that the login mechanism correctly processes valid credentials and returns the appropriate user data. It also verifies that the RemoteDataSource class is correctly wired with the ApiServiceClient.
Test Case 2: Failed Login
Test Name:should throw an exception if login fails
Purpose:
This test checks the behavior of the login method when invalid credentials are provided. It ensures that the method throws a DioException with the appropriate status code (400) when the login attempt fails.
Steps:
LoginRequest with invalid credentials.login method.DioException with a 400 status code.test('should throw an exception if login fails', () async {
final loginRequest = LoginRequest(
username: 'emilys', password: 'emilyspass', expiresInMins: 60);
try {
await remoteDataSource.login(loginRequest);
fail('Expected a error with status code 400 but got a success.');
} on DioException catch (e) {
expect(e.response?.statusCode, equals(400));
} catch (e) {
fail('Expected a error but got a different exception: $e');
}
});This test ensures that the system correctly handles error scenarios during login attempts. By catching and verifying the DioException, the test confirms that the appropriate error handling logic is in place.
Conclusion and Best Practices
setUp function.login method, ensuring comprehensive coverage of the functionality.