add testcase for the usage of no-arg constructor for DateTimeDeserializer

Author: Yu Hoi Chau

src/test/java/com/fasterxml/jackson/datatype/joda/AnnotationTest.java

@@ -0,0 +1,40 @@
+package com.fasterxml.jackson.datatype.joda;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.datatype.joda.deser.DateTimeDeserializer;
+import com.fasterxml.jackson.datatype.joda.ser.DateTimeSerializer;
+import org.joda.time.DateTime;
+import org.joda.time.DateTimeZone;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+
+class AClass{
+    @JsonSerialize(using = DateTimeSerializer.class) // old serializer
+    @JsonDeserialize(using = DateTimeDeserializer.class) // new deserializer
+    private DateTime createdOn = DateTime.now(DateTimeZone.UTC); // some dummy data for the sake of brevity
+
+    public DateTime getCreatedOn() {
+        return createdOn;
+    }
+
+    public void setCreatedOn(DateTime createdOn) {
+        this.createdOn = createdOn;
+    }
+}
+
+public class AnnotationTest {
+
+    @Test
+    public void testSomeMethod() throws Exception {
+        ObjectMapper objectMapper = new ObjectMapper();
+        AClass initialObject = new AClass();
+        String serializedObject = objectMapper.writeValueAsString(initialObject);
+        AClass deserializedObject = objectMapper.readValue(serializedObject, AClass.class);
+        assertEquals(deserializedObject.getCreatedOn(), initialObject.getCreatedOn());
+    }
+
+}