instance `save()` behavior when nothing has changed

Hello,

How should I expect instance.save() to behave when invoked on an instance that has not been modified since load?

From http://docs.sequelizejs.com/en/latest/docs/instances/#updating-saving-persisting-an-instance:

When you call save without changing any attribute, this method will execute nothing;

From http://docs.sequelizejs.com/en/latest/api/instance/#saveoptions-promisethiserrorsvalidationerror:

Validate this instance, and if the validation passes, persist it to the database.

From nodejs (sequelize 3.3.2):

> MyModel.findOne().then(s => s.save());
Executing (default): UPDATE "mymodels" SET "updated_at"='2015-08-15 02:06:57.325 +00:00' WHERE "id" = '3681e9f8-25a5-4863-9015-dd90d3a4a2e2'

If the intended behavior of save is indeed to not update the timestamp (when no fields have changed), how can I achieve that effect, in a future-proof way?

[janmeier]

Yeah, it seems the documentation needs to be cleared up a bit on this point.

It is intentional that nothing is saved if nothing has changed. You can manually mark a column as changed to force a save: instance.changed('updatedAt', true)

[igrayson]

Okay. It really doesn’t seem like a documentation issue when I compare what you said with the observed behavior.

It is intentional that nothing is saved if nothing has changed.

MyModel.findOne().then(s => s.save());
Executing (default): UPDATE "mymodels" SET "updated_at"='2015-08-15 02:06:57.325 +00:00' WHERE "id" = '3681e9f8-25a5-4863-9015-dd90d3a4a2e2'

(nothing changed; something saved)