1 files changed, 23 insertions, 0 deletions
diff --git a/runtime/commonMain/src/kotlinx/serialization/modules/SerializerAlreadyRegisteredException.kt b/runtime/commonMain/src/kotlinx/serialization/modules/SerializerAlreadyRegisteredException.kt
new file mode 100644
index 00000000..f86517c7
--- /dev/null
+++ b/runtime/commonMain/src/kotlinx/serialization/modules/SerializerAlreadyRegisteredException.kt
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2017-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.serialization.modules
+
+import kotlin.reflect.KClass
+
+/**
+ * Thrown on attempt to register serializer (for contextual or polymorphic serialization)
+ * for some class twice.
+ *
+ * Registering in the same module twice is prohibited. In case you are combining modules
+ * with [SerialModule.plus], consider using [SerialModule.overwriteWith] if you want overwriting behaviour.
+ */
+public class SerializerAlreadyRegisteredException private constructor(msg: String) : IllegalArgumentException(msg) {
+    constructor(
+        baseClass: KClass<*>,
+        concreteClass: KClass<*>
+    ) : this("Serializer for $concreteClass already registered in the scope of $baseClass")
+
+    public constructor(forClass: KClass<*>) : this("Serializer for $forClass already registered in this module")
+}