Active Model Lint Tests
You can test whether an object is compliant with the Active Model API by
ActiveModel::Lint::Tests in your TestCase. It will
include tests that tell you whether your object is fully compliant, or if
not, which aspects of the API are not implemented.
Note an object is not required to implement all APIs in order to work with Action Pack. This module only intends to provide guidance in case you want all features out of the box.
These tests do not attempt to determine the semantic correctness of the
returned values. For instance, you could implement
true, and the tests would pass. It is up to you
to ensure that the values are semantically meaningful.
Objects you pass in are expected to return a compliant object from a call
to_model. It is perfectly fine for
Returns an object that implements (attribute) defined which returns an Array of Strings that are the errors for the attribute in question. If localization is used, the Strings should be localized for the current locale. If no error is present, this method should return an empty Array.
# File activemodel/lib/active_model/lint.rb, line 97 def test_errors_aref assert model.respond_to?(:errors), "The model should respond to errors" assert model.errors[:hello].is_a?(Array), "errors# should return an Array" end
Model.model_name and Model#model_name must return a string with some
convenience methods: #
:plural. Check ActiveModel::Naming for more information.
# File activemodel/lib/active_model/lint.rb, line 79 def test_model_naming assert model.class.respond_to?(:model_name), "The model class should respond to model_name" model_name = model.class.model_name assert model_name.respond_to?(:to_str) assert model_name.human.respond_to?(:to_str) assert model_name.singular.respond_to?(:to_str) assert model_name.plural.respond_to?(:to_str) assert model.respond_to?(:model_name), "The model instance should respond to model_name" assert_equal model.model_name, model.class.model_name end
Responds to persisted?
Returns a boolean that specifies whether the object has been persisted yet. This is used when calculating the URL for an object. If the object is not persisted, a form for that object, for instance, will route to the create action. If it is persisted, a form for the object will routes to the update action.
# File activemodel/lib/active_model/lint.rb, line 69 def test_persisted? assert model.respond_to?(:persisted?), "The model should respond to persisted?" assert_boolean model.persisted?, "persisted?" end
Responds to to_key
Returns an Enumerable of all (primary)
key attributes or nil if
model.persisted? is false. This is
dom_id to generate unique ids for the object.
# File activemodel/lib/active_model/lint.rb, line 29 def test_to_key assert model.respond_to?(:to_key), "The model should respond to to_key" def model.persisted?() false end assert model.to_key.nil?, "to_key should return nil when `persisted?` returns false" end
Responds to to_param
Returns a string representing the object's key suitable for use in URLs
Implementers can decide to either raise an exception or provide a default
in case the record uses a composite primary key. There are no tests for
this behavior in lint because it doesn't make sense to force any of the
possible implementation strategies on the implementer. However, if the
resource is not persisted?, then
to_param should always return
# File activemodel/lib/active_model/lint.rb, line 46 def test_to_param assert model.respond_to?(:to_param), "The model should respond to to_param" def model.to_key()  end def model.persisted?() false end assert model.to_param.nil?, "to_param should return nil when `persisted?` returns false" end
Responds to to_partial_path
Returns a string giving a relative path. This is used for looking up partials. For example, a BlogPost model might return “blog_posts/blog_post”
# File activemodel/lib/active_model/lint.rb, line 57 def test_to_partial_path assert model.respond_to?(:to_partial_path), "The model should respond to to_partial_path" assert_kind_of String, model.to_partial_path end