How can I unit test Future<void> function in flutter?-CodePudding

I have Future function called addRating that add data to Firestore, I am new to testing in flutter, how do I achieve it?

Function I want to test:

Future<void> addRating(RatingModel rating) async {
  await _firestore.collection('rating').doc(rating.ratingId).set(rating.toJson());
}

What I have tried:

final firestore = FakeFirebaseFirestore();
test('can add to firestore', () async{
  RatingRepository ratingRepository = RatingRepository(firestore: firestore);
  RatingModel model = RatingModel(feedback: 'test', merchantId: '1', orderId: '1', rating: 1, ratingId: '1');
  await expectLater(()async{await ratingRepository.addRating(model);}, isNull);
});

CodePudding user response：

You are almost there. The idea of using await is correct. You could do the following

final firestore = FakeFirebaseFirestore();
test('can add to firestore', () async{
  RatingRepository ratingRepository = RatingRepository(firestore: firestore);
  RatingModel model = RatingModel(feedback: 'test', merchantId: '1', orderId: '1', rating: 1, ratingId: '1');
  await ratingRepository.addRating(model);
  expect(...); // Whatever condition should be fullfilled afterwards. 
});

This works because the test function itslef is marked as async, allowing you to use await like that inside the function body.

The last line of course depends on your use case. Should a rating be increased? Should it be stored somewhere?

CodePudding user response：

I think If you are expecting nothing then you just need to verify that the function is called:

verify(()async{await ratingRepository.addRating(model);})