[RESTEASY-1684]

Adding test for pull request #1240.

jaxrs/providers/jackson2/src/test/java/org/jboss/resteasy/test/nextgen/providers/jackson/NullEntityProxyTest.java

@@ -0,0 +1,87 @@
+package org.jboss.resteasy.test.nextgen.providers.jackson;
+
+import static org.jboss.resteasy.test.TestPortProvider.generateURL;
+
+import javax.annotation.Resource;
+import javax.ws.rs.Consumes;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.MediaType;
+
+import org.jboss.resteasy.client.jaxrs.ResteasyClient;
+import org.jboss.resteasy.client.jaxrs.ResteasyClientBuilder;
+import org.jboss.resteasy.client.jaxrs.ResteasyWebTarget;
+import org.jboss.resteasy.test.BaseResourceTest;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * RESTEASY-1684
+ * 
+ * @author <a href="ron.sigal@jboss.com">Ron Sigal</a>
+ * @version $Revision: 1.1 $
+ *
+ * Copyright Dec 13, 2017
+ */
+public class NullEntityProxyTest extends BaseResourceTest
+{
+   @Resource
+   @Path("")
+   public interface Hello
+   {
+      @POST
+      @Path("json")
+      @Consumes(MediaType.APPLICATION_JSON)
+      @Produces(MediaType.TEXT_PLAIN)
+      public String json(Car car);
+   }
+
+   @Resource
+   @Path("")
+   public static class HelloImpl implements Hello
+   {
+      @POST
+      @Path("json")
+      @Consumes(MediaType.APPLICATION_JSON)
+      @Produces(MediaType.TEXT_PLAIN)
+      public String json(Car car)
+      {
+         return car == null ? "null" : car.getColor();
+      }
+   }
+
+   public static class Car
+   {   
+      private String color;
+
+      public String getColor() {
+         return color;
+      }
+      public void setColor(String color) {
+         this.color = color;
+      }
+   }
+
+   @Before
+   public void setUp() throws Exception
+   {
+      addPerRequestResource(HelloImpl.class);
+   }
+
+   @SuppressWarnings("deprecation")
+   @Test
+   public void testNullParameter()
+   {
+      ResteasyClient client = new ResteasyClientBuilder().build();
+      ResteasyWebTarget target = client.target(generateURL(""));
+      Hello hello = target.proxy(Hello.class);
+      Car car = new Car();
+      car.setColor("blue");
+      String color = hello.json(car);
+      Assert.assertEquals("should be \"blue\"", "blue", color);
+      color = hello.json(null);
+      Assert.assertEquals("should be \"null\"", "null", color);  
+   }
+}