Active Model Lint Tests
You can test whether an object is compliant with the Active Model API by
including 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 valid?
to
always return 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 to_model
. It is perfectly fine for to_model
to
return self
.
- T
Passes if the object's model responds to errors
and if
calling [](attribute)
on the result of this method returns an
array. Fails otherwise.
errors[attribute]
is used to retrieve the errors of a model
for a given attribute. If errors are present, the method should return 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, the method should return an empty array.
Passes if the object's model responds to model_name
both
as an instance method and as a class method, and if calling this method
returns a string with some convenience methods: :human
,
:singular
and :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
Passes if the object's model responds to persisted?
and if
calling this method returns either true
or false
.
Fails otherwise.
persisted?
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
route to the update action.
Passes if the object's model responds to to_key
and if
calling this method returns nil
when the object is not
persisted. Fails otherwise.
to_key
returns an Enumerable of all (primary) key attributes
of the model, and is used to a generate unique DOM id for the object.
Passes if the object's model responds to to_param
and if
calling this method returns nil
when the object is not
persisted. Fails otherwise.
to_param
is used to represent the object's key 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.
# File activemodel/lib/active_model/lint.rb, line 44 def test_to_param assert model.respond_to?(:to_param), "The model should respond to to_param" def model.to_key() [1] end def model.persisted?() false end assert model.to_param.nil?, "to_param should return nil when `persisted?` returns false" end
Passes if the object's model responds to to_partial_path
and if calling this method returns a string. Fails otherwise.
to_partial_path
is used for looking up partials. For example,
a BlogPost model might return “blog_posts/blog_post”.