org.koin.android.error.MissingAndroidContextException: when try to test app with context

Question

I want to write test for koin . I use RoomDatabase , which receives context in constructor. App works well but test fails

Can't resolve Application instance. Please use androidContext() function in your KoinApplication configuration.

Answer 1

if you want context in your modules, you should pass context in your start koin method

// start Koin!
    startKoin {

      // declare used Android context
      androidContext(this@MyApplication)

      // declare modules
      modules(yourModule)
    }

and use these libraries

    // Koin AndroidX Scope features
    implementation "org.koin:koin-android-scope:2.0.1"
// Koin AndroidX ViewModel features
    implementation 'org.koin:koin-androidx-viewmodel:2.0.1'
// Koin AndroidX Experimental features
    implementation "org.koin:koin-android-ext:2.0.1"

Answer 2

Make sure to set your context when you start koin. Then you should be able to access it via androidContext() in your modules.

startKoin {
    androidContext(this@App)
    modules(...)
    ...
}

Answer 3

For unittests I have implemented this

@file:JvmName("KoinTest")
package com.myapp.di

import androidx.test.core.app.ApplicationProvider
import org.koin.android.ext.koin.androidContext
import org.koin.core.context.startKoin

fun startKoin() {
    startKoin {
        androidContext(ApplicationProvider.getApplicationContext())
        modules(listOf(applicationModule, networkModule))
    }
}

fun stopKoin() {
    org.koin.core.context.stopKoin()
}

I can call this from our old Java tests as KoinTest.startKoin() or just startKoin() in Kotlin. I call these from the @Before and @After block appropriately. The android context is set with the new AndroidX test library function.

Answer 4

You cannot test Room in unit testing with Koin. You can only test in instrumented tests.

Answer 5

in my case, I edit my application class to :

class App : Application() {
    override fun onCreate() {
        super.onCreate()

        startKoin {

            androidContext(this@App)

            modules(viewModelModule)
        }
    }
}