RBusarow

class CoroutineTestRule : TestRule,  
                          TestPolymorphicCoroutineScope by TestPolymorphicCoroutineScope() { 

  val dispatcher = coroutineContext[ContinuationInterceptor] as TestCoroutineDispatcher  
    
  override fun apply(  
    base: Statement, description: Description?  
  ) = object : Statement() {  
    override fun evaluate() {  
      @Throws(Throwable::class)  

RBusarow

@ExperimentalCoroutinesApi  
interface TestPolymorphicCoroutineScope : TestCoroutineScope,  
  DefaultCoroutineScope,  
  IOCoroutineScope,  
  MainCoroutineScope,  
  MainImmediateCoroutineScope,  
  UnconfinedCoroutineScope
  
@ExperimentalCoroutinesApi  
private class TestPolymorphicCoroutineScopeImpl(

RBusarow

val scope = MainCoroutineScope()
val progressIndicator = ProgressIndicator(scope)

RBusarow

@Module  
object CoroutineScopeModule {  
  
  @Provides  
  fun provideMainCoroutineScope(): MainCoroutineScope = MainCoroutineScope()  
}

RBusarow

public fun MainCoroutineScope(  
  job: Job = SupervisorJob()  
): MainCoroutineScope = object : MainCoroutineScope {  
  override val coroutineContext = job + Dispatchers.Main  
}  
  
public fun MainCoroutineScope(  
  context: CoroutineContext  
): MainCoroutineScope = object : MainCoroutineScope {  
  override val coroutineContext = context + Dispatchers.Main  

RBusarow

class ProgressIndicator(
  private val coroutineScope: MainCoroutineScope
) {
  ...
}

RBusarow

interface DefaultCoroutineScope : CoroutineScope  
interface IOCoroutineScope : CoroutineScope  
interface MainCoroutineScope : CoroutineScope  
interface MainImmediateCoroutineScope : CoroutineScope  
interface UnconfinedCoroutineScope : CoroutineScope

RBusarow

@Qualifier  
annotation class MainCoroutineScope  
  
@Module  
object CoroutineScopeModule {  
  
  @Provides  
  @MainCoroutineScope  
  fun provideMainCoroutineScope(): CoroutineScope = CoroutineScope(Job() + Dispatchers.Main)
  

RBusarow

class ProgressIndicator(
  private val coroutineScope: CoroutineScope
) {  
  fun start(  
    timeout: Milliseconds,   
    message: String? = null  
  ) = coroutineScope.launch {  
    ...  
  }  
} 

RBusarow

class MyCoroutineScope : CoroutineScope {  
  override val coroutineContext = Job() + Dispatchers.Main  
}  
val someScope = CoroutineScope(Job() + Dispatchers.IO)