Add failing test for GitHub #196

src/test/kotlin/com/fasterxml/jackson/module/kotlin/test/github/failing/Github196.kt

@@ -0,0 +1,17 @@
+package com.fasterxml.jackson.module.kotlin.test.github.failing
+
+import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.module.kotlin.readValue
+import com.fasterxml.jackson.module.kotlin.test.expectFailure
+import org.junit.Test
+import kotlin.test.assertSame
+
+class TestGithub196 {
+    @Test
+    fun testUnitSingletonDeserialization() {
+        // An empty object should be deserialized as *the* Unit instance, but is not
+        expectFailure<AssertionError>("GitHub #196 has been fixed!") {
+            assertSame(jacksonObjectMapper().readValue("{}"), Unit)
+        }
+    }
+}