Validator Attachment¶ ↑

It works with Rails >=4.0. (For Rails >=3.0 use version 1.x) Helps me test my validations on Models with less code. Assuming that Rails validations are already tested, by Rails, then when I have a validation on an attribute of a Model, I just want to test whether the validation is there. Nothing more.

Assuming that you have a Model like the following:

class MyAwesomeModel < ActiveRecord::Base
  validates :last_name, :presence => true
end

In your test:

it "last name has to be present" do
  expect(ActiveModel::Validations::PresenceValidator.is_attached?(MyAwesomeModel, :last_name)).to be true
end

will test that your last_name attribute on the model MyAwesomeModel has a :presence validation attached. Note that ActiveModel::Validations::PresenceValidator is the class that comes with Rails ActiveModel.

Note: “attached?” is an alias for “is_attached?” and you can use whatever you feel like better.

Optionally, you can also check whether the correct options are attached too. So, if you have a Model like:

class MyAwesomeModel < ActiveRecord::Base
  validates :last_name, :length => { :minimum => 3, :maximum => 60 }
end

In your test:

it "last name should not be of correct length" do
  # you do not have to check for all options
  it { expect(ActiveModel::Validations::LengthValidator.is_attached?(MyAwesomeModel, :last_name, { :minimum => 3 })).to be true }
  it { expect(ActiveModel::Validations::LengthValidator.is_attached?(MyAwesomeModel, :last_name, { :maximum => 60 })).to be true }

  # or you can check for all
  it { expect(ActiveModel::Validations::LengthValidator.is_attached?(MyAwesomeModel, :last_name, { :minimum => 3, :maximum => 60 })).to be true }

  # or you can ask for those and only those, i.e. exact content match
  it { expect(!ActiveModel::Validations::LengthValidator.is_attached?(MyAwesomeModel, :last_name, { :maximum => 60 }, true)).to be true }
  it { expect(ActiveModel::Validations::LengthValidator.is_attached?(MyAwesomeModel, :last_name, { :minimum > 60, :maximum => 60 }, true)).to be true }
end

Another example with with_options:

class User < ActiveRecord::Base
    with_options :if => :is_admin? do |admin|
      admin.validates :password, :length => { :minimum => 10 }
      admin.validates :username, :presence => true
    end
end

You can test this as follows:

test "user admin validators" do
  it { expect(ActiveModel::Validations::LengthValidator.is_attached?(User, :password, { :minimum => 10, :if => :is_admin? })).to be true }
  it { exepct(ActiveModel::Validations::PresenceValidator.is_attached?(User, :username, { :if => :is_admin? })).to be true }
end

In the file validator_attachment_test.rb you will see a lot of tests that I run to test the gem and you can get ideas on you should use your assertions. You will see there an example with a custom validator too.

It is easy to derive the class of the validator. The rule of thumb is that all Validators are ActiveModel validators with one exception that of :uniqueness, which is an ActiveRecord Validator. However, here is a list that can help you:

:acceptance

ActiveModel::Validations::AcceptanceValidator

:confirmation

ActiveModel::Validations::ConfirmationValidator

:exclusion

ActiveModel::Validations::ExclusionValidator

:format

ActiveModel::Validations::FormatValidator

:inclusion

ActiveModel::Validations::InclusionValidator

:length

ActiveModel::Validations::LengthValidator

:numericality

ActiveModel::Validations::NumericalityValidator

:uniqueness

ActiveRecord::Validations::UniquenessValidator

:presence

ActiveModel::Validations::PresenceValidator

If you find a problem with validator_attachment, please open an issue on issue on GitHub

See the CHANGELOG for release notes and versions of this ‘gem`. Please, note that `gem` follows Semantic Versioning but patch version number will be increased if either bug fixes are introduced (as Semantic Versioning defines) or if tests or documents are added.