1 files changed, 113 insertions, 0 deletions
diff --git a/formats/json-tests/commonTest/src/kotlinx/serialization/features/JsonClassDiscriminatorTest.kt b/formats/json-tests/commonTest/src/kotlinx/serialization/features/JsonClassDiscriminatorTest.kt
new file mode 100644
index 00000000..5eebe218
--- /dev/null
+++ b/formats/json-tests/commonTest/src/kotlinx/serialization/features/JsonClassDiscriminatorTest.kt
@@ -0,0 +1,113 @@
+/*
+ * Copyright 2017-2021 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.builtins.*
+import kotlinx.serialization.json.*
+import kotlinx.serialization.modules.*
+import kotlin.test.*
+
+class JsonClassDiscriminatorTest : JsonTestBase() {
+    @Serializable
+    @JsonClassDiscriminator("sealedType")
+    sealed class SealedMessage {
+        @Serializable
+        @SerialName("SealedMessage.StringMessage")
+        data class StringMessage(val description: String, val message: String) : SealedMessage()
+
+        @SerialName("EOF")
+        @Serializable
+        object EOF : SealedMessage()
+    }
+
+    @Serializable
+    @JsonClassDiscriminator("abstractType")
+    abstract class AbstractMessage {
+        @Serializable
+        @SerialName("Message.StringMessage")
+        data class StringMessage(val description: String, val message: String) : AbstractMessage()
+
+        @Serializable
+        @SerialName("Message.IntMessage")
+        data class IntMessage(val description: String, val message: Int) : AbstractMessage()
+    }
+
+
+    @Test
+    fun testSealedClassesHaveCustomDiscriminator() {
+        val messages = listOf(
+            SealedMessage.StringMessage("string message", "foo"),
+            SealedMessage.EOF
+        )
+        val expected =
+            """[{"sealedType":"SealedMessage.StringMessage","description":"string message","message":"foo"},{"sealedType":"EOF"}]"""
+        assertJsonFormAndRestored(
+            ListSerializer(SealedMessage.serializer()),
+            messages,
+            expected,
+        )
+    }
+
+    @Test
+    fun testAbstractClassesHaveCustomDiscriminator() {
+        val messages = listOf(
+            AbstractMessage.StringMessage("string message", "foo"),
+            AbstractMessage.IntMessage("int message", 42),
+        )
+        val module = SerializersModule {
+            polymorphic(AbstractMessage::class) {
+                subclass(AbstractMessage.StringMessage.serializer())
+                subclass(AbstractMessage.IntMessage.serializer())
+            }
+        }
+        val json = Json { serializersModule = module }
+        val expected =
+            """[{"abstractType":"Message.StringMessage","description":"string message","message":"foo"},{"abstractType":"Message.IntMessage","description":"int message","message":42}]"""
+        assertJsonFormAndRestored(
+            ListSerializer(
+                AbstractMessage.serializer()
+            ), messages, expected, json
+        )
+    }
+
+    @Serializable
+    @JsonClassDiscriminator("message_type")
+    abstract class Base
+
+    @Serializable
+    abstract class ErrorClass : Base()
+
+    @Serializable
+    data class Message(val message: Base, val error: ErrorClass?)
+
+    @Serializable
+    @SerialName("my.app.BaseMessage")
+    data class BaseMessage(val message: String) : Base()
+
+    @Serializable
+    @SerialName("my.app.GenericError")
+    data class GenericError(@SerialName("error_code") val errorCode: Int) : ErrorClass()
+
+
+    @Test
+    fun testDocumentationInheritanceSample() {
+        val module = SerializersModule {
+            polymorphic(Base::class) {
+                subclass(BaseMessage.serializer())
+            }
+            polymorphic(ErrorClass::class) {
+                subclass(GenericError.serializer())
+            }
+        }
+        val json = Json { serializersModule = module }
+        assertJsonFormAndRestored(
+            Message.serializer(),
+            Message(BaseMessage("not found"), GenericError(404)),
+            """{"message":{"message_type":"my.app.BaseMessage","message":"not found"},"error":{"message_type":"my.app.GenericError","error_code":404}}""",
+            json
+        )
+    }
+}