Koin scoped view model

ViewModelOnClearedTest.kt

package com.example

import androidx.fragment.app.FragmentActivity
import androidx.lifecycle.ViewModel
import org.junit.After
import org.junit.Assert.assertEquals
import org.junit.Before
import org.junit.Test
import org.junit.runner.RunWith
import org.koin.androidx.scope.currentScope
import org.koin.androidx.viewmodel.dsl.viewModel
import org.koin.androidx.viewmodel.ext.android.viewModel
import org.koin.core.context.startKoin
import org.koin.core.context.stopKoin
import org.koin.core.parameter.parametersOf
import org.koin.core.qualifier.named
import org.koin.core.scope.ScopeID
import org.koin.dsl.module
import org.robolectric.Robolectric
import org.robolectric.RobolectricTestRunner

private const val ON_CLEARED = "MyViewModel#onCleared"

/**
 * Requires at least:
 * implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"
 *
 * See also:
 * https://developer.android.com/jetpack/androidx/releases/lifecycle#declaring_dependencies
 */
class MyViewModel(private val onClearedString: String) : ViewModel() {
    fun function() = "function"

    override fun onCleared() {
        println(onClearedString)
        Spy.text = onClearedString
        super.onCleared()
    }
}

object Spy {
    lateinit var text: String
}

/**
 * Requires:
 *  - koin-core
 *  - koin-androidx-viewmodel
 *  - koin-androidx-scope
 *
 * See also: https://insert-koin.io/docs/2.0/getting-started/introduction/
 */
class MyActivity : FragmentActivity() {
    private val myViewModel: MyViewModel by viewModel { parametersOf(currentScope.id) }

    fun function() = println(myViewModel.function())

    override fun onDestroy() {
        println("MyActivity#onDestroy")

        super.onDestroy()
    }
}

/**
 * Requires:
 *  - JUnit 4.12
 *  - Robolectric 4.2.x: http://robolectric.org/getting-started/
 */
@RunWith(RobolectricTestRunner::class)
class ViewModelOnClearedTest {
    @Before
    fun before() {
        val module = module {
            scope(named<MyActivity>()) {
                scoped {
                    "$ON_CLEARED for scope id = $id"
                }
            }
            viewModel { (scopeID: ScopeID) ->
                println("Instantiating MyViewModel for scope ID = $scopeID")
                MyViewModel(getScope(scopeID).get())
            }
        }

        startKoin {
            // printLogger(Level.DEBUG) // Enable this to see what Koin does
            modules(module)
        }
    }

    @After
    fun after() = stopKoin()

    @Test
    fun `MyViewModel#onCleared is called after last activity goes away`() {
        val controller = Robolectric.buildActivity(MyActivity::class.java).setup()
        val myActivity = controller.get()
        val id = myActivity.currentScope.id
        myActivity.function()
        controller.destroy()

        // Verify the Spy's text property is set correctly
        assertEquals("$ON_CLEARED for scope id = $id", Spy.text)

        // Also look at the console as some strings are printed, note the order of the prints
    }
}