Fix #654: inclusion of array should output an empty array if the array is empty in the doc

Author: Burak Serdar

crud/src/main/java/com/redhat/lightblue/eval/Projector.java

@@ -205,6 +205,8 @@ private JsonNode project(JsonNodeFactory factory,
                                     project(factory, contextPath, cursor, ctx, true);
                             cursor.parent();
                             LOGGER.debug("Child object:{}", newNode);
+                        } else {
+                            newNode=factory.arrayNode();
                         }
                     } else {
                         newNode = fieldNode;

crud/src/test/java/com/redhat/lightblue/eval/ProjectorTest.java

@@ -411,6 +411,18 @@ public void dont_project_unwanted_emptyArray() throws Exception {
         Assert.assertNull(pdoc.get(new Path("field6.nf5")));
     }
 
+    @Test
+    public void project_wanted_emptyArray() throws Exception {
+        // Set nf5 to an empty array
+        jsonDoc.modify(new Path("field6.nf5"), JSON_NODE_FACTORY.arrayNode(), true);
+        Projection p = EvalTestContext.projectionFromJson("{'field':'field6.*'}");
+        Projector projector = Projector.getInstance(p, md);
+        JsonDoc pdoc = projector.project(jsonDoc, JSON_NODE_FACTORY);
+        System.out.println(pdoc);
+        Assert.assertNotNull(pdoc.get(new Path("field6")));
+        Assert.assertNotNull(pdoc.get(new Path("field6.nf5")));
+    }
+
     @Test
     public void include_then_exclude_626() throws Exception {
         Projection p = EvalTestContext.projectionFromJson("[ {'field':'field7','include':true,'match':{'field':'elemf3','op':'>','rvalue':3}},"