Associations now raises `ArgumentError` on name conflicts.

[laurocaetano]

It's an attempt to fix #13217.

In order to avoid unexpected behavior, dangerous association names should raise ArgumentError.

This way, models like this:

class Project < ActiveRecord::Base
  has_many :errors
end
# It was deleting all the errors when saving, 
# because the valid? method calls errors.clear. 
# see https://github.com/rails/rails/blob/master/activemodel/lib/active_model/validations.rb#L312-L314

Will raise ArgumentError, saying that the association name will generate an instance method which is already defined by ActiveRecord::Base.

[carlosantoniodasilva]

has_one?

[laurocaetano]

Good catch, thanks :)
copy/paste

[carlosantoniodasilva]

I think you don't need to use an else block here, you can left the code untouched and just add the conditional to raise.

[laurocaetano]

👍

[carlosantoniodasilva]

now raise

[carlosantoniodasilva]

I think that'd be include instance or class methods.

[carlosantoniodasilva]

How about: but this will conflict with a method #{name} already defined by Active Record. Please choose a different association name. so that we direct the user towards a solution.

[laurocaetano]

👍

[chancancode]

Might want to use an anonymous Class in the tests instead of Post.belongs_to ... because the belongs_to call might have irreversible side-effect on the Post class, which might break other tests cases.

In a real app this wouldn't matter because they except would just blow up the app completely.

[laurocaetano]

@carlosantoniodasilva @chancancode updated with the suggested changes. Thanks guys :)

[carlosantoniodasilva]

Thanks!

[laurocaetano]

Thanks 💚