module ActiveModel::Lint::Tests - activemodel-4.2.4 Documentation

# module ActiveModel::Lint::Tests

## 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`.

### Public Instance Methods

test_errors_aref() click to toggle source

## Errors Testing¶ ↑

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 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

test_model_naming() click to toggle source

## Naming¶ ↑

Model.model_name and Model#model_name must return a string with some convenience methods: # `:human`, `:singular` and `:plural`. Check ActiveModel::Naming for more information.

    # File 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

test_persisted?() click to toggle source

## 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 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

test_to_key() click to toggle source

## Responds to `to_key`¶ ↑

Returns an Enumerable of all (primary) key attributes or nil if `model.persisted?` is false. This is used by `dom_id` to generate unique ids for the object.

    # File 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

test_to_param() click to toggle source

## Responds to `to_param`¶ ↑

Returns a string representing the object's key suitable for use in URLs or `nil` if `model.persisted?` is `false`.

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 `nil`.

    # File 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() [1] end
      def model.persisted?() false end
      assert model.to_param.nil?, "to_param should return nil when `persisted?` returns false"
    end

test_to_partial_path() click to toggle source

## 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 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

### Private Instance Methods

assert_boolean(result, name) click to toggle source

    # File lib/active_model/lint.rb, line 108
    def assert_boolean(result, name)
      assert result == true || result == false, "#{name} should be a boolean"
    end

model() click to toggle source

    # File lib/active_model/lint.rb, line 103
    def model
      assert @model.respond_to?(:to_model), "The object should respond to to_model"
      @model.to_model
    end