1 files changed, 51 insertions, 0 deletions
diff --git a/core/commonTest/src/kotlinx/serialization/SerializersLookupInterfaceTest.kt b/core/commonTest/src/kotlinx/serialization/SerializersLookupInterfaceTest.kt
new file mode 100644
index 00000000..fc770575
--- /dev/null
+++ b/core/commonTest/src/kotlinx/serialization/SerializersLookupInterfaceTest.kt
@@ -0,0 +1,51 @@
+package kotlinx.serialization
+
+import kotlinx.serialization.test.*
+import kotlin.test.*
+
+class SerializersLookupInterfaceTest {
+
+    interface I
+
+    @Polymorphic
+    interface I2
+
+    @Suppress("SERIALIZER_TYPE_INCOMPATIBLE")
+    @Serializable(PolymorphicSerializer::class)
+    interface I3
+
+    @Serializable
+    @SerialName("S")
+    sealed interface S
+
+    // TODO: not working because (see #1207, plugin does not produce companion object for interfaces)
+    // We even have #1853 with tests for that
+    // @Serializable(ExternalSerializer::class)
+    // interface External
+
+
+    @Test
+    fun testSealedInterfaceLookup() {
+        val serializer = serializer<S>()
+        assertTrue(serializer is SealedClassSerializer)
+        assertEquals("S", serializer.descriptor.serialName)
+    }
+
+    @Test
+    fun testInterfaceLookup() {
+        // Native does not have KClass.isInterface
+        if (isNative() || isWasm()) return
+
+        val serializer1 = serializer<I>()
+        assertTrue(serializer1 is PolymorphicSerializer)
+        assertEquals("kotlinx.serialization.Polymorphic<I>", serializer1.descriptor.serialName)
+
+        val serializer2 = serializer<I2>()
+        assertTrue(serializer2 is PolymorphicSerializer)
+        assertEquals("kotlinx.serialization.Polymorphic<I2>", serializer2.descriptor.serialName)
+
+        val serializer3 = serializer<I3>()
+        assertTrue(serializer3 is PolymorphicSerializer)
+        assertEquals("kotlinx.serialization.Polymorphic<I3>", serializer3.descriptor.serialName)
+    }
+}