issue#103 Add delay for Dispatcher.Default to have time to propagate exceptions

test-util-android/src/main/java/org/fnives/test/showcase/android/testutil/synchronization/idlingresources/OkHttp3IdlingResource.kt

@@ -21,6 +21,7 @@ class OkHttp3IdlingResource private constructor(
     init {
         val currentCallback = dispatcher.idleCallback
         dispatcher.idleCallback = Runnable {
+            sleepForDispatcherDefaultCallInRetrofitErrorState()
             callback?.onTransitionToIdle()
             currentCallback?.run()
         }
@@ -28,7 +29,13 @@ class OkHttp3IdlingResource private constructor(
 
     override fun getName(): String = name
 
-    override fun isIdleNow(): Boolean = dispatcher.runningCallsCount() == 0
+    override fun isIdleNow(): Boolean {
+        val isIdle = dispatcher.runningCallsCount() == 0
+        if (isIdle) {
+            sleepForDispatcherDefaultCallInRetrofitErrorState()
+        }
+        return isIdle
+    }
 
     override fun registerIdleTransitionCallback(callback: IdlingResource.ResourceCallback?) {
         this.callback = callback
@@ -46,5 +53,20 @@ class OkHttp3IdlingResource private constructor(
             if (client == null) throw NullPointerException("client == null")
             return OkHttp3IdlingResource(name, client.dispatcher)
         }
+
+        /**
+         * This is required, because in case of Errors Retrofit uses Dispatcher.Default to suspendThrow
+         * see: retrofit2.KotlinExtensions.kt Exception.suspendAndThrow
+         * Relevant code issue: https://github.com/square/retrofit/blob/6cd6f7d8287f73909614cb7300fcde05f5719750/retrofit/src/main/java/retrofit2/KotlinExtensions.kt#L121
+         * This is the current suggested approach to their problem with Unchecked Exceptions
+         *
+         * Sadly Dispatcher.Default cannot be replaced yet, so we can't swap it out in tests:
+         * https://github.com/Kotlin/kotlinx.coroutines/issues/1365
+         *
+         * This brings us to this sleep for now.
+         */
+        private fun sleepForDispatcherDefaultCallInRetrofitErrorState() {
+            Thread.sleep(200L)
+        }
     }
 }

test-util-android/src/main/java/org/fnives/test/showcase/android/testutil/synchronization/mainThreadSynchronization.kt

@@ -28,7 +28,7 @@ fun runOnUIAwaitOnCurrent(action: () -> Unit) {
 
 fun loopMainThreadFor(delay: Long) {
     if (Looper.getMainLooper().thread == Thread.currentThread()) {
-        Thread.sleep(200L)
+        Thread.sleep(delay)
     } else {
         Espresso.onView(ViewMatchers.isRoot()).perform(LoopMainThreadFor(delay))
     }