1 files changed, 73 insertions, 0 deletions
diff --git a/src/test/java/com/fasterxml/jackson/databind/ser/CyclicTypeSerTest.java b/src/test/java/com/fasterxml/jackson/databind/ser/CyclicTypeSerTest.java
new file mode 100644
index 000000000..d6cdf2756
--- /dev/null
+++ b/src/test/java/com/fasterxml/jackson/databind/ser/CyclicTypeSerTest.java
@@ -0,0 +1,73 @@
+package com.fasterxml.jackson.databind.ser;
+
+import java.util.*;
+
+
+import com.fasterxml.jackson.databind.*;
+
+/**
+ * Simple unit tests to verify that it is possible to handle
+ * potentially cyclic structures, as long as object graph itself
+ * is not cyclic. This is the case for directed hierarchies like
+ * trees and DAGs.
+ */
+public class CyclicTypeSerTest
+    extends BaseMapTest
+{
+    static class Bean
+    {
+        Bean _next;
+        final String _name;
+
+        public Bean(Bean next, String name) {
+            _next = next;
+            _name = name;
+        }
+
+        public Bean getNext() { return _next; }
+        public String getName() { return _name; }
+
+        public void assignNext(Bean n) { _next = n; }
+    }
+
+    /*
+    /**********************************************************
+    /* Types
+    /**********************************************************
+     */
+
+    private final ObjectMapper MAPPER = newJsonMapper();
+
+    public void testLinked() throws Exception
+    {
+        Bean last = new Bean(null, "last");
+        Bean first = new Bean(last, "first");
+        Map<String,Object> map = writeAndMap(MAPPER, first);
+
+        assertEquals(2, map.size());
+        assertEquals("first", map.get("name"));
+
+        @SuppressWarnings("unchecked")
+        Map<String,Object> map2 = (Map<String,Object>) map.get("next");
+        assertNotNull(map2);
+        assertEquals(2, map2.size());
+        assertEquals("last", map2.get("name"));
+        assertNull(map2.get("next"));
+    }
+
+    /**
+     * Test for verifying that [JACKSON-158] works as expected
+     */
+    public void testSelfReference() throws Exception
+    {
+        Bean selfRef = new Bean(null, "self-refs");
+        Bean first = new Bean(selfRef, "first");
+        selfRef.assignNext(selfRef);
+        Bean[] wrapper = new Bean[] { first };
+        try {
+            writeAndMap(MAPPER, wrapper);
+        } catch (JsonMappingException e) {
+            verifyException(e, "Direct self-reference leading to cycle");
+        }
+    }
+}