Fail-fast for validations

[nirname]

I have got an interaction that does a lot of different things with an email

class VerifyEmail < BaseInteraction
  string :email

  validates :email, presence: true, email: true

  validate do
    errors.add(:email, 'please use another domain') unless domain.allowed?
    errors.add(:email, 'user not found') unless user
    errors.add(:email, 'user is blocked') if user.blocked?
  end

  def execute do
    errors.add(:email, 'too many login attempts) if rate_limit_exceeded?
  end
end

All the errors scattered across the logic. I'd like to get only the first error, probably, stop all other validations at some point. Fair enough, I can bypass it by asking errors.messages[:email] to be blank? or calling return or next at some point.

class VerifyEmail < BaseInteraction
  string :email

  validates :email, presence: true, email: true, if: -> { errors.message[:email].blank? }

  validate do
    errors.add(:email, 'please use another domain') && next unless domain.allowed?
    errors.add(:email, 'user not found') && next unless user
    errors.add(:email, 'user is blocked') && next if user.blocked?
  end

  def execute do
    errors.add(:email, 'too many login attempts) and return if rate_limit_exceeded?
  end
end

Perhaps this is not even the extension that should be added here, and it is related more to validations mechanism rather than to this gem. But since this idea came to me while I was working with it that is what i'd like to see to reduce the boilerplate:

class VerifyEmail < BaseInteraction
  fail_fast :email

  # keep it clean as in the first example
end

Even if it is not the right place, may be someone will be inspired by this topic, and implement it somewhere else, or redirect me to the correct place for such a discussion. May be, if it is more or less appropriate I will implement it by myself.

[antulik]

I see there are couple of options.

1. use next or return

Like you suggested

2 use :strict error mode

errors.add(:name, :invalid, strict: true)

that will raise ActiveModel::StrictValidationFailed which you'll need to rescue in around block, ActiveInteraction does not rescue it.

3. use halt!

Similar to #1, but this one allows to stop from any sub method.

see for more https://github.com/antulik/active_interaction-extras#halt

[AaronLasseigne]

I try to keep it in line with how Rails works. In fact, the validation is straight out of Rails. @antulik gave a good response. I think generally this would be outside of the scope of this gem and more of a Rails question.

Thanks for the question!