Allowed option to persist side effects of virtual setters during an update

lib/model.js

@@ -1596,6 +1596,7 @@ module.exports = (function() {
    * @param  {Array}        [options.fields]                Fields to update (defaults to all fields)
    * @param  {Boolean}      [options.validate=true]         Should each row be subject to validation before it is inserted. The whole insert will fail if one row fails validation
    * @param  {Boolean}      [options.hooks=true]            Run before / after bulk update hooks?
+   * @param  {Boolean}      [options.persistSideEffects=true] Whether or not to update the side effects of any virtual setters.
    * @param  {Boolean}      [options.individualHooks=false] Run before / after update hooks?. If true, this will execute a SELECT followed by individual UPDATEs. A select is needed, because the row data needs to be passed to the hooks
    * @param  {Boolean}      [options.returning=false]       Return the affected rows (only for postgres)
    * @param  {Number}       [options.limit]                 How many rows to update (only for mysql and mariadb)
@@ -1615,7 +1616,8 @@ module.exports = (function() {
       hooks: true,
       individualHooks: false,
       returning: false,
-      force: false
+      force: false,
+      persistSideEffects: true
     }, options || {});
 
     options.type = QueryTypes.BULKUPDATE;
@@ -1650,6 +1652,11 @@ module.exports = (function() {
         var build = self.build(values);
         build.set(self._timestampAttributes.updatedAt, values[self._timestampAttributes.updatedAt], { raw: true });
 
+        if ( options.persistSideEffects ) {
+          values = Utils._.assign(values, Utils._.pick(build.get(), build.changed()));
+          options.fields = Utils._.union(options.fields, Object.keys(values));
+        }
+
         // We want to skip validations for all other fields
         options.skip = Utils._.difference(Object.keys(self.attributes), Object.keys(values));
         return build.hookValidate(options).then(function(attributes) {