Hi there! I want to write some JUnit tests for a class which injects some dependencies via Koin. I w...

# koin

[Henning B]

Hi there!
I want to write some JUnit tests for a class which injects some dependencies via Koin. I want to mock these dependencies and deliver them via Koin. In my test class I did the following:
* I implement the KoinTest interface
* create the mock
* create a Koin module with the mock inside
* at setup I start Koin

The output is as follows:

[DEBUG] [Koin] instances started in 0.024431 ms
[DEBUG] [Koin] +- get 'xyz.application.LocalizationHelper'

org.koin.core.error.NoBeanDefFoundException: No definition found for 'xyz.application.LocalizationHelper' has been found. Check your module definitions.

Am I doing something wrong or isn't it possible to inject mocks that way? If not, what would be the best practice to achive what I want via Koin?

Thanks a lot!

[gvetri]

I had this error yesterday. In my module defitnition i used single { MockWalletUseCase() } to create my mock dependency. Then in my test i used private val mockWalletUseCase: MockWalletUseCase by inject()

[gvetri]

This repo has a example: https://github.com/InsertKoinIO/getting-started-koin-core.git 😄 Hope it helps

[Henning B]

Thank you for the link looks like the HelloMockTest is doing exactly the same thing I want to achieve. Will help for sure 🙂

[gvetri]

😄 👍

[Henning B]

just had some more time to inspect the github. They don't create a module for testing but use the actual module which is also used in the actual app.
than they use declareMock to overwrite the implemantations with mocks.

Did I see that correctly?

[gvetri]

I think it’s ok. If you want to mock it, and verify it with mockito (HelloMocktest.kt). If you want to assert the return value from a method you can use what is in the HelloAppTest.kt