fix: move default field assignment to refreshAttributes rather than init

lib/model.js

@@ -252,10 +252,6 @@ module.exports = (function() {
       if (definition.hasOwnProperty('validate')) {
         self.Instance.prototype.validators[name] = definition.validate;
       }
-
-      if (definition.field === undefined) {
-        definition.field = name;
-      }
     });
 
     this._hasBooleanAttributes = !!this._booleanAttributes.length;
@@ -325,6 +321,10 @@ module.exports = (function() {
         options.fieldName = attribute;
         options._modelAttribute = true;
 
+        if (options.field === undefined) {
+          options.field = attribute;
+        }
+
         if (options.hasOwnProperty(type)) {
           _custom[attribute] = options[type];
         }
@@ -1751,7 +1751,7 @@ module.exports = (function() {
         for (attribute in attributes) {
           rawAttribute = Model.rawAttributes[attribute];
           if (rawAttribute && rawAttribute.field !== rawAttribute.fieldName) {
-            attributes[Model.rawAttributes[attribute].field] = attributes[attribute];
+            attributes[rawAttribute.field] = attributes[attribute];
             delete attributes[attribute];
           }
         }