module Fields::Serializer::ActiveRecord::Errors

Return a hash with errors of the model merged with errors of the given associated models.

{
  name: ["can't be blank"],
  age:  ["must be greater than 18"],
  cars: {
    "xxx-xxxxxxxx-xxx-xxxxxx" => {
      make: ["can't be blank"],
      type: ["can't be blank"]
    },
    "0" => {
      make: ["can't be blank"],
      year: ["must be greater than 1800"]
    }
    "1" => {
      year: ["must be greater than 1800"]
    }
  }
}

where "xxx-xxxxxxxx-xxx-xxxxxx" is the id of an associated model and
      an incremental integer id is given to those associated models with empty id.
      Similar to ActiveRecord nested attributes notation.

# File lib/fields/serializer/active_record/errors.rb, line 29
def deep_errors(*association_keys)
  association_keys.inject(errors.to_h) do |error_tree, association_key|
    associate = send(association_key)
    next(error_tree) unless associate
    associate = associate.to_a if self.class.reflections[association_key.to_s].collection?
    error_tree.merge!(association_key => __associate_errors(associate))
  end
end

{ “xxx-xxxxxxxx-xxx-xxxxxx” => { name: [“can't be blank”], age: [“can't be less than 18”] },

"0" => { name: ["can't be blank"], age: ["can't be less than 18"] },

# File lib/fields/serializer/active_record/errors.rb, line 42
def __associate_errors(associate)
  Array(associate).map.with_index { |object, i| [object.id || i, object.errors.to_h] }.to_h
end