Fail early when one defines an attribute that overlaps with any method in Attributor::Model

[konstantin-dzreev]

In the example below attribute ":attributes" overlaps with pre existing method "attributes" defined in Attributor::Model.

  class Data < Attributor::Model
    attributes do
      attribute :foo, String
      attribute :attributes, Hash
    end
  end

This compiles and runs. And you do not see any obvious issues until you try to load and validate your attributor model instance where it fails with a weird error:

Attributor::Hash can not validate object of type Hash for $.attributes 

It would be nice to fail earlier (ideally in the model definition) or at least to have a better error message.

[blanquer]

yes, we do have that issue in general (as #99 sort of states).
This particular case of the attributes method, though, I think is a slightly different, as it is pertaining to a Model only, and it clashes with an instance method we explicitly set in the model instances:
https://github.com/rightscale/attributor/blob/master/lib/attributor/types/model.rb#L145-L147

We might be able to get rid of that method or rename (i.e., _attributes) it so it doesn't clash so directly. This would require a lot of care and attention though, as these inheritable types have dependencies on top that might be difficult to bend...

[konstantin-dzreev]

It would be nice to have a fix that is not for 'attributes' only but for any method that may overlap with a defined attribute (any method that is defined on a model instance).

[blanquer]

oh absolutely, I simply wanted to point out that this issue is "similar" to #99 , but it is quite different in the sense that has to do with instance-level methods (while #99 is mostly about class-level methods). But either way, a better story for non-overlapping methods would be great regardless.

[careo]

Duplicate of #71, as that's really how we should end up fixing this.