From 8c45f6cd67f9960bf93fcd52769a38e4e6419fa6 Mon Sep 17 00:00:00 2001
From: Ankush Gupta <me@ankushg.com>
Date: Thu, 12 Nov 2020 17:57:54 -0500
Subject: [PATCH] add test to reproduce issue

---
 .../json/DynamicPolymorphismTest.kt           | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/formats/json/jsTest/src/kotlinx/serialization/json/DynamicPolymorphismTest.kt b/formats/json/jsTest/src/kotlinx/serialization/json/DynamicPolymorphismTest.kt
index 514853f62..c03c7f7e3 100644
--- a/formats/json/jsTest/src/kotlinx/serialization/json/DynamicPolymorphismTest.kt
+++ b/formats/json/jsTest/src/kotlinx/serialization/json/DynamicPolymorphismTest.kt
@@ -21,6 +21,10 @@ class DynamicPolymorphismTest {
         @Serializable
         @SerialName("type_child")
         data class TypeChild(val type: String) : Sealed(2)
+
+        @Serializable
+        @SerialName("nullable_child")
+        data class NullableChild(val nullable: String?): Sealed(3)
     }
 
     @Serializable
@@ -103,6 +107,38 @@ class DynamicPolymorphismTest {
         }
     }
 
+    @Test
+    fun testNullable() {
+        val nonNullChild = Sealed.NullableChild("nonnull")
+        encodeAndDecode(Sealed.serializer(), nonNullChild, arrayJson) {
+            assertEquals("nullable_child", this[0])
+            val dynamicValue = this[1]
+            assertEquals(nonNullChild.nullable, dynamicValue.nullable)
+            assertEquals(nonNullChild.intField, dynamicValue.intField)
+            assertEquals(2, fieldsCount(dynamicValue))
+        }
+        encodeAndDecode(Sealed.serializer(), nonNullChild, objectJson) {
+            assertEquals("nullable_child", this.type)
+            assertEquals(nonNullChild.nullable, this.nullable)
+            assertEquals(nonNullChild.intField, this.intField)
+            assertEquals(3, fieldsCount(this))
+        }
+
+        val nullChild = Sealed.NullableChild(null)
+        encodeAndDecode(Sealed.serializer(), nullChild, arrayJson) {
+            assertEquals("nullable_child", this[0])
+            val dynamicValue = this[1]
+            assertEquals(nullChild.nullable, dynamicValue.nullable)
+            assertEquals(nullChild.intField, dynamicValue.intField)
+            assertEquals(2, fieldsCount(dynamicValue))
+        }
+        encodeAndDecode(Sealed.serializer(), nullChild, objectJson) {
+            assertEquals("nullable_child", this.type)
+            assertEquals(nullChild.nullable, this.nullable)
+            assertEquals(nullChild.intField, this.intField)
+            assertEquals(3, fieldsCount(this))
+        }
+    }
     @Test
     fun testObject() {
         val value = Sealed.ObjectChild