1 files changed, 19 insertions, 1 deletions
diff --git a/reactive/kotlinx-coroutines-jdk9/test/IntegrationTest.kt b/reactive/kotlinx-coroutines-jdk9/test/IntegrationTest.kt
index 5bfddfee..5b3542ad 100644
--- a/reactive/kotlinx-coroutines-jdk9/test/IntegrationTest.kt
+++ b/reactive/kotlinx-coroutines-jdk9/test/IntegrationTest.kt
@@ -5,10 +5,12 @@
 package kotlinx.coroutines.jdk9
 
 import kotlinx.coroutines.*
+import kotlinx.coroutines.exceptions.*
 import org.junit.Test
 import kotlinx.coroutines.flow.flowOn
 import org.junit.runner.*
 import org.junit.runners.*
+import kotlin.contracts.*
 import java.util.concurrent.Flow as JFlow
 import kotlin.coroutines.*
 import kotlin.test.*
@@ -129,4 +131,20 @@ class IntegrationTest(
         assertEquals(n, last)
     }
 
-}
-\ No newline at end of file
+}
+
+@OptIn(ExperimentalContracts::class)
+internal suspend inline fun <reified E: Throwable> assertCallsExceptionHandlerWith(
+    crossinline operation: suspend (CoroutineExceptionHandler) -> Unit): E {
+    contract {
+        callsInPlace(operation, InvocationKind.EXACTLY_ONCE)
+    }
+    val handler = CapturingHandler()
+    return withContext(handler) {
+        operation(handler)
+        handler.getException().let {
+            assertTrue(it is E, it.toString())
+            it
+        }
+    }
+}