1 files changed, 62 insertions, 0 deletions
diff --git a/formats/json-tests/jvmTest/src/kotlinx/serialization/StacktraceRecoveryTest.kt b/formats/json-tests/jvmTest/src/kotlinx/serialization/StacktraceRecoveryTest.kt
new file mode 100644
index 00000000..dcf3e959
--- /dev/null
+++ b/formats/json-tests/jvmTest/src/kotlinx/serialization/StacktraceRecoveryTest.kt
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2017-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.serialization
+
+import kotlinx.coroutines.*
+import kotlinx.serialization.descriptors.*
+import kotlinx.serialization.encoding.*
+import kotlinx.serialization.json.*
+import kotlinx.serialization.json.internal.*
+import kotlinx.serialization.modules.*
+import kotlin.test.*
+
+class StacktraceRecoveryTest {
+    @Serializable
+    private class Data(val s: String)
+
+    private class BadDecoder : AbstractDecoder() {
+        override val serializersModule: SerializersModule = EmptySerializersModule()
+        override fun decodeElementIndex(descriptor: SerialDescriptor): Int = 42
+    }
+
+    @Test
+    fun testJsonDecodingException() = checkRecovered("JsonDecodingException") {
+        Json.decodeFromString<String>("42")
+    }
+
+    @Test
+    fun testJsonEncodingException() = checkRecovered("JsonEncodingException") {
+        Json.encodeToString(Double.NaN)
+    }
+
+    @Test
+    // checks simple name because UFE is internal class
+    fun testUnknownFieldException() = checkRecovered("UnknownFieldException") {
+        val serializer = Data.serializer()
+        serializer.deserialize(BadDecoder())
+    }
+
+    private fun checkRecovered(exceptionClassSimpleName: String, block: () -> Unit) = runBlocking {
+        val result = runCatching {
+            callBlockWithRecovery(block)
+        }
+        assertTrue(result.isFailure, "Block should have failed")
+        val e = result.exceptionOrNull()!!
+        assertEquals(exceptionClassSimpleName, e::class.simpleName!!)
+        val cause = e.cause
+        assertNotNull(cause, "Exception should have cause: $e")
+        assertEquals(e.message, cause.message)
+        assertEquals(exceptionClassSimpleName, e::class.simpleName!!)
+    }
+
+    // KLUDGE: A separate function with state-machine to ensure coroutine DebugMetadata is generated. See KT-41789
+    private suspend fun callBlockWithRecovery(block: () -> Unit) {
+        yield()
+        // use withContext to perform switch between coroutines and thus trigger exception recovery machinery
+        withContext(NonCancellable) {
+            block()
+        }
+    }
+}