fix(instance): update() should only save the provided attributes (leaving other …

…changes attributes alone), closes #2341

lib/instance.js

@@ -638,7 +638,9 @@ module.exports = (function() {
 
           // Ensure new values are on Instance, and reset previousDataValues
           result.dataValues = _.extend(result.dataValues, values);
-          result._previousDataValues = _.clone(result.dataValues);
+          options.fields.forEach(function (field) {
+            result._previousDataValues[field] = result.dataValues[field];
+          });
         }).tap(function(result) {
           // Run after hook
           if (options.hooks) {
@@ -707,7 +709,14 @@ module.exports = (function() {
    * @alias updateAttributes
    */
   Instance.prototype.update = function(values, options) {
-    return this.set(values, {attributes: options && options.fields}).save(options);
+    options = options || {};
+    if (Array.isArray(options)) options = {fields: options};
+
+    this.set(values, {attributes: options.fields});
+
+    if (!options.fields) options.fields = _.intersection(Object.keys(values), this.changed());
+
+    return this.save(options);
   };
   Instance.prototype.updateAttributes = Instance.prototype.update;
 

test/instance/update.test.js

@@ -93,6 +93,24 @@ describe(Support.getTestDialectTeaser('Instance'), function() {
       });
     });
 
+    it('should only save passed attributes', function () {
+      var user = this.User.build();
+      return user.save().then(function () {
+        user.set('validateTest', 5);
+        expect(user.changed('validateTest')).to.be.ok;
+        return user.updateAttributes({
+          validateCustom: '1'
+        });
+      }).then(function () {
+        expect(user.changed('validateTest')).to.be.ok;
+        expect(user.validateTest).to.be.equal(5);
+      }).then(function () {
+        return user.reload();
+      }).then(function () {
+        expect(user.validateTest).to.not.be.equal(5);
+      });
+    });
+
     it('should not set attributes that are not specified by fields', function () {
       var User = this.sequelize.define('User' + config.rand(), {
         name: DataTypes.STRING,