Add check for #844

src/test/kotlin/com/fasterxml/jackson/module/kotlin/test/github/GitHub844.kt

@@ -0,0 +1,30 @@
+package com.fasterxml.jackson.module.kotlin.test.github
+
+import com.fasterxml.jackson.annotation.JsonTypeInfo
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.module.kotlin.readValue
+import com.fasterxml.jackson.module.kotlin.registerKotlinModule
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "_type")
+private sealed class BaseClass
+
+private data class ChildClass(val text: String) : BaseClass()
+
+class GitHub844 {
+    @Test
+    fun test() {
+        val json = """
+        {
+            "_type": "ChildClass",
+            "text": "Test"
+        }
+        """
+
+        val jacksonObjectMapper = ObjectMapper().registerKotlinModule()
+        val message = jacksonObjectMapper.readValue<BaseClass>(json)
+
+        assertEquals(ChildClass("Test"), message)
+    }
+}