1 files changed, 31 insertions, 0 deletions
diff --git a/formats/json-tests/commonTest/src/kotlinx/serialization/features/PartiallyCustomSerializerTest.kt b/formats/json-tests/commonTest/src/kotlinx/serialization/features/PartiallyCustomSerializerTest.kt
new file mode 100644
index 00000000..9ad4afec
--- /dev/null
+++ b/formats/json-tests/commonTest/src/kotlinx/serialization/features/PartiallyCustomSerializerTest.kt
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2017-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.serialization.features
+
+import kotlinx.serialization.*
+import kotlinx.serialization.encoding.*
+import kotlinx.serialization.json.Json
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+@Serializable(WithNull.Companion::class)
+data class WithNull(@SerialName("value") val nullable: String? = null) {
+    @Serializer(forClass = WithNull::class)
+    companion object : KSerializer<WithNull> {
+        override fun serialize(encoder: Encoder, value: WithNull) {
+            val elemOutput = encoder.beginStructure(descriptor)
+            if (value.nullable != null) elemOutput.encodeStringElement(descriptor, 0, value.nullable)
+            elemOutput.endStructure(descriptor)
+        }
+    }
+}
+
+class PartiallyCustomSerializerTest {
+    @Test
+    fun partiallyCustom() {
+        assertEquals("""{"value":"foo"}""", Json.encodeToString(WithNull.serializer(), WithNull("foo")))
+        assertEquals("""{}""", Json.encodeToString(WithNull.serializer(), WithNull()))
+    }
+}