Unit test for abstract classes in projects generated by the CLI

[meysammahfouzi]

First I created a project:

stacked create app bluesky

Then added a view:

stacked create view feed

Then added a service:

stacked create service http_api

After that I modified FeedViewModel to have a reference to the service:

class FeedViewModel extends BaseViewModel {
  HttpApiService httpApiService = locator<HttpApiService>();
}

Then wrote a unit test for the viewmodel and it passed ✅ (feed_viewmodel_test.dart):

import '../helpers/test_helpers.dart';

FeedViewModel _getModel() => FeedViewModel();

void main() {
  group('FeedViewModel Tests -', () {
    setUp(() => registerServices());
    tearDown(() => locator.reset());
    test('test', () async {
      final model = _getModel();
    });
  });
}

Now I decided to abstract the api service. So I manually created the following file: api_service.dart:

abstract class ApiService{
  Future<bool> likePost(int postId);
}

And changed the HttpApiService class:

class HttpApiService implements ApiService {
  @override
  Future<bool> likePost(int postId) {
    // TODO: implement likePost
    throw UnimplementedError();
  }
}

And in the app.dart file, changed the following line:

LazySingleton(classType: HttpApiService),

To the following:

LazySingleton(classType: HttpApiService, asType: ApiService),

And also updated the FeedViewModel class to locate the ApiService instead of HttpApiService:

class FeedViewModel extends BaseViewModel {
  ApiService apiService = locator<ApiService>();
}

And also ran the stacked generate command to make sure all of the files are correct.

Then I ran the unit test again and it failed 🔴 with the following error:

Bad state: GetIt: Object/factory with type ApiService is not registered inside GetIt. 

To fix this, I modified the test_helpers.dart file and executed stacked generate:

MockHttpApiService getAndRegisterHttpApiService() {
  _removeRegistrationIfExists<HttpApiService>();
  final service = MockHttpApiService();
  locator.registerSingleton<ApiService>(service);
  return service;
}

And the test passed ✅

Did I modify the correct files? Is there something I should have done differently?

[ferrarafer]

Hi @meysammahfouzi should be like below.

MockApiService getAndRegisterApiService() {
  _removeRegistrationIfExists<ApiService>();
  final service = MockApiService();
  locator.registerSingleton<ApiService>(service);
  return service;
}

Locator will do the rest under the hood.