mocking a class that depends on firebase in a non-uI test for remote config - kotlin

Question

I have this class that exposes remote configs to others. I thought by creating a class, I would just mock it when testing others that use it but so far, firebase is blocking me. Not sure what I am doing wrong exactly.
class AppRemoteConfig #Inject constructor() {
private var remoteConfig: FirebaseRemoteConfig = Firebase.remoteConfig
private fun setListeningInterval(): Long {
if (BuildConfig.DEBUG){
return 0;
}
return 86400;
}
init {
val configSettings = remoteConfigSettings {
minimumFetchIntervalInSeconds = setListeningInterval()
}
remoteConfig.setConfigSettingsAsync(configSettings)
remoteConfig.setDefaultsAsync(R.xml.remote_config_defaults)
remoteConfig.fetchAndActivate()
.addOnCompleteListener(OnCompleteListener{
if (it.isSuccessful) {
remoteConfig.activate()
}
})
}
fun getString(key: String): String {
return this.remoteConfig.getString(key)
}
}
Now a class uses it this way:
class GetRData #Inject constructor(
private val _remoteConfig: AppRemoteConfig
) {
operator fun invoke(key): String {
try {
return _remoteConfig.getString(key)
} catch(ex: Exception){
return ""
}
return ""
}
}
Now I want to test GetRData class but I get the error: Default FirebaseApp is not initialized in this process null. Make sure to call FirebaseApp.initializeApp(Context) first.
here is what I have tried:
class GetRDataTest {
private var appRemoteConfig = mockk<AppRemoteConfig>(relaxed = true)
private lateinit var getRData : GetRData
#Before
fun setUp(){
getRData = GetRData(appRemoteConfig)
}
#Test
fun `Should get string value`() {
every { appRemoteConfig.getString("status") } returns "red"
val result = getRData.invoke("status")
verify { appRemoteConfig.getString("status") }
Truth.assertThat(result).isEqualTo("red")
}
}