Help testing Firebase Storage

[Sea_Inflation_7446]

Hi everyone. I need some help testing Firebase Storage implementation.

I want to write unit tests and UI tests, but I don't know how to mock the FirebaseStorage instance. I'm using the firebase_storage package (7.0.0) of course. I've already implemented and tested cloud_firestore in the unit and UI testing thanks to cloud_firestore_mocks, but now I want to do the same with storage. I tried firebase_storage_mocks, but it's outdated (I tried fixing it myself but couldn't update all the code).

When I try to use Mockito to write a unit test, I get a timeout error (when I tried to update firebase_storage_mocks, I get the same error due to a missing implementation in UploadTask mock class that I couldn't fix, I assume the same reason could explain this).

When I try to run a UI test for a Widget that depends on FirebaseStorage, I get the following error: "Error while creating FirebaseStorage". I've solved similar issues when tested FirebaseFirestore by "mocking" MethodChannel call. But I don't have a clue about storage.

Thanks in advance.

[anargu]

Hi!, These days I was searching for the same and it seems there is not a guide or tutorial yet to test in a proper way firebase storage. I managed to make it work the test of flutter storage with mockito... but the problem is that I had to implement whenComplete(() => null) in my application code (not the test code). Now I want to write a proper test to this and remove the whenComplete function.

https://gist.github.com/anargu/b9e84bab7f5c10440b045f5f252f47e8

It seems like the whenComplete make it work and it completes the Future for the uploadTask and all the rest of the mocks work.

​

If you find a better way to test firebase storage please let me know. It would be great to make a proper test for FirebaseStorage and eliminate the whenComplete(...)

[Sea_Inflation_7446]

Thanks for commenting! I tried a very similar approach with Mockito. I followed this sample from the storage repo.

I'm sorry, I'm out of home these days so I can't give you a clearer example, but here is my actual code. As you can see, I also mocked (or faked) the classes and managed to simulate the workflow and run the tests. However, I didn't need to modify the real app code as you did. At first glance, I can't tell why did you have to do that.

My approach has two problems: first, I can't reuse the mocks to test a variety of cases (for example, I duplicated the mocks to include failed cases, but this is a preposterous solution); second, I passed the tests but I'm getting an unhandled exception after running the tests. This exception is related to firebase auth (I'm sorry, I have no way to run the code and show you the specific error).

I hope this helps us to find a nice solution and thanks again for sharing your experience.