Espresso Idling Resource with Coroutines

DispatcherProvider.kt

package com.lukasdylan.dicoding.made.utils

import androidx.annotation.VisibleForTesting
import kotlinx.coroutines.CoroutineDispatcher
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.ExperimentalCoroutinesApi

interface DispatcherProvider {
    val main: CoroutineDispatcher
    val background: CoroutineDispatcher
    val commonPool: CoroutineDispatcher
}

class DispatcherProviderImpl : DispatcherProvider {
    override val main: CoroutineDispatcher
        get() = Dispatchers.Main
    override val background: CoroutineDispatcher
        get() = Dispatchers.IO
    override val commonPool: CoroutineDispatcher
        get() = Dispatchers.Default
}

@ExperimentalCoroutinesApi
@VisibleForTesting
class TestDispatcherProvider : DispatcherProvider {
    override val main: CoroutineDispatcher
        get() = Dispatchers.Unconfined
    override val background: CoroutineDispatcher
        get() = Dispatchers.Unconfined
    override val commonPool: CoroutineDispatcher
        get() = Dispatchers.Unconfined
}

fun DispatcherProvider.espressoIdlingResource(increment: Boolean) {
    /**
     * When we initialize [androidx.test.espresso.idling.CountingIdlingResource] on [EspressoIdlingResource] object,
     * they need to check a string whether is empty or not using TextUtils.isEmpty(), thus this method cannot be mocked
     * on Unit Test. So we need to check the [kotlinx.coroutines.CoroutineDispatcher] if it used [Dispatchers.Main]
     * instead of [Dispatchers.Unconfined] on Unit Test
     */
    if (this.main == Dispatchers.Main) {
        if (increment) {
            EspressoIdlingResource.increment()
        } else {
            EspressoIdlingResource.decrement()
        }
    }
}