add $ref and remove type for models

lib/model-helper.js

@@ -5,6 +5,7 @@
  */
 var _cloneDeep = require('lodash.clonedeep');
 var translateDataTypeKeys = require('./translate-data-type-keys');
+var TYPES_PRIMITIVE = ['array', 'boolean', 'integer', 'number', 'null', 'object', 'string'];
 
 /**
  * Export the modelHelper singleton.
@@ -83,6 +84,11 @@ var modelHelper = module.exports = {
       // Change mismatched keys.
       prop = translateDataTypeKeys(prop);
 
+      if (TYPES_PRIMITIVE.indexOf(prop.type) === -1 ){
+        prop.$ref = prop.type;
+        delete prop.type;
+      }
+
       // Assign this back to the properties object.
       properties[key] = prop;
 

test/model-helper.test.js

@@ -118,7 +118,7 @@ describe('model-helper', function() {
           address: Address
         });
         var prop = def.properties.address;
-        expect(prop).to.eql({ type: 'Address' });
+        expect(prop).to.eql({ $ref: 'Address' });
       });
 
     });