CoroutineDispatcherRule.kt

package olx.com.delorean.view.filter.viewmodel

import kotlinx.coroutines.CoroutineDispatcher
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.test.TestCoroutineDispatcher
import kotlinx.coroutines.test.TestCoroutineScope
import kotlinx.coroutines.test.resetMain
import kotlinx.coroutines.test.setMain
import org.junit.rules.TestWatcher
import org.junit.runner.Description
import kotlin.coroutines.ContinuationInterceptor


class CoroutineDispatcherRule : TestWatcher(), TestCoroutineScope by TestCoroutineScope() {

    val testDispatcher = TestCoroutineDispatcher()

    override fun finished(description: Description?) {
        super.finished(description)
        Dispatchers.resetMain()
        testDispatcher.cleanupTestCoroutines()
    }

    override fun starting(description: Description?) {
        super.starting(description)
        Dispatchers.setMain(this.coroutineContext[ContinuationInterceptor] as CoroutineDispatcher)
    }
}