com.android.tools.r8.internal.Jc: Space characters in SimpleName exception are not allowed prior to DEX version 040

I’m trying to using backticks ` in the definition of my instrumented tests. I don’t understand why compiler complains about a strange error:

Caused by: com.android.tools.r8.internal.Jj: com.android.tools.r8.internal.Jc: Space characters in SimpleName 'given a closebottomsheetevent eventlistener onCloseBottomSheet should be called' are not allowed prior to DEX version 040

My test is a pretty standard instrumented test for compose

package com.dooitu.mobile.android.ui.homefeed

import android.content.Context
import androidx.activity.ComponentActivity
import androidx.compose.runtime.State
import androidx.compose.runtime.mutableStateOf
import androidx.compose.ui.test.junit4.createAndroidComposeRule
import com.dooitu.mobile.android.ui.homefeed.components.HomeFeedEvent
import com.dooitu.mobile.android.ui.homefeed.models.HomeFeedScreenEventListener
import com.dooitu.mobile.android.ui.theme.DooituTheme
import org.junit.Rule
import org.junit.Test
import org.koin.androidx.compose.get

class HomeFeedScreenTest {
    @get:Rule
    // Use a dummy activity instead of real MainActivity
    val composeTestRule = createAndroidComposeRule<ComponentActivity>()
    private var triggeredEventId: Int? = null
    private val eventListener = object : HomeFeedScreenEventListener {
        override fun onCloseBottomSheet() {
            triggeredEventId = ON_CLOSE_BOTTOM_SHEET_EVENT_ID
        }

        override fun onOpenComments(postId: String, numberOfComments: Int) {
            triggeredEventId = ON_OPEN_COMMENTS_EVENT_ID
        }

        override fun onOpenShare(shareLink: String, context: Context) {
            TODO("Not yet implemented")
        }

        override fun onOpenPostSingleView(postId: String) {
            TODO("Not yet implemented")
        }

        override fun onOpenPostActions(postId: String, userId: String) {
            TODO("Not yet implemented")
        }

        override fun onOpenPostDetails(postId: String) {
            TODO("Not yet implemented")
        }

        override fun onProfileImageClicked(userId: String, isCurrentUser: Boolean) {
            TODO("Not yet implemented")
        }
    }
    private val updateViewModel = HomeFeedUpdateViewModel()

    private fun startScenario(state: State<HomeFeedState>) {
        composeTestRule.setContent {
            DooituTheme.SurfaceContainer {
                HomeFeedScreen(
                    state = state,
                    viewModel = get(),
                    cacheDataSourceFactory = get(),
                    getReloadedPostFlow = updateViewModel::reloadedPost,
                    eventsListener = eventListener,
                    logScreenView = {}
                )
            }
        }
    }

    @Test
    fun `given a closebottomsheetevent eventlistener on close bottom sheet should be called` () {
        val closeBottomSheetState = mutableStateOf(
            HomeFeedState(
                emptyList(),
                emptyList(),
                event = HomeFeedEvent.CloseBottomSheet
            )
        )
        // Start the app
        startScenario(closeBottomSheetState)
        assert(triggeredEventId == ON_CLOSE_BOTTOM_SHEET_EVENT_ID)
    }
}

If I remove backticks and spaces test compiles without any problem 🙁

>Solution :

That syntax is super-cool but it’s not currently supported by Android runtime
https://kotlinlang.org/docs/coding-conventions.html#names-for-test-methods

I think in the doc is missing the note about it’s available in the unit tests on Android (that works on the JVM) and not in the instrumented tests (Android runtime)