Can't validate association properties

[dxg]

Because of the change introduced by this issue it's no longer possible to validate association generated fields. There is a failing test case here.

I can see a few possible resolutions but am unsure which is best:

1. Modify the hasOne association so that it adds first class properties to the model, rather than association_properties. Perhaps there's a good reason why they're separate.
2. Add all_properties which would be the sum of properties and association_properties. I think this would warrant adding a method to Model such as add_property(...) else it might be hard to track everything.
3. Check all types of properties in handleValidations although association_properties doesn't store full properties like properties does. Seems to be just a list.
4. Modify the DDL sync so that it's possible to explicitly define the association column in the db.define call (currently, if there is overlap, the sync function will define the column twice, causing an SQL error).

What do you think?

[dresende]

Extra properties are really tricky but they only happen in hasMany associations. The extra properties should be available in opts.extra in Instance.js. Perhaps we could just change the handleValidations method to look at them also.

[dxg]

The issue isn't extra properties, it's association_properties created by hasOne.
They aren't available in opts.extras and whilst they could be added there and handleValidations modified to also check those, I'm not sure what value is added by maintaining two lists [properties & extras].

Having to remember to check every type of property all the time will keep introducting corner case-bugs much like this one.

I think we should have one list composed of all properties that belong to the model, much like we have one model_fields list.

hasOne would add a property to this list, and handleValidations would check this list. Driver sync would create the table definition from this one list. It should simplify the code and reduce the likelihood of related bugs.