Module: RSpec::Rails::Mocks

Defined in:
lib/rspec/rails/mocks.rb

Defined Under Namespace

Modules: ActiveModelInstanceMethods, ActiveModelStubExtensions, ActiveRecordInstanceMethods, ActiveRecordStubExtensions

Instance Method Summary collapse

Instance Method Details

#mock_model(string_or_model_class, stubs = {}) ⇒ Object

Creates a test double representing string_or_model_class with common ActiveModel methods stubbed out. Additional methods may be easily stubbed (via add_stubs) if stubs is passed. This is most useful for impersonating models that don’t exist yet.

NOTE that only ActiveModel’s methods, plus new_record?, are stubbed out implicitly. new_record? returns the inverse of persisted?, and is present only for compatibility with extension frameworks that have yet to update themselves to the ActiveModel API (which declares persisted?, not new_record?).

string_or_model_class can be any of:

* A String representing a Class that does not exist
* A String representing a Class that extends ActiveModel::Naming
* A Class that extends ActiveModel::Naming



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# File 'lib/rspec/rails/mocks.rb', line 52

def mock_model(string_or_model_class, stubs = {})
  if String === string_or_model_class
    if Object.const_defined?(string_or_model_class)
      model_class = Object.const_get(string_or_model_class)
    else
      model_class = Object.const_set(string_or_model_class, Class.new do
        extend ActiveModel::Naming
      end)
    end
  else
    model_class = string_or_model_class
  end

  unless model_class.kind_of? ActiveModel::Naming
    raise ArgumentError.new <<-EOM
The mock_model method can only accept as its first argument:
  * A String representing a Class that does not exist
  * A String representing a Class that extends ActiveModel::Naming
  * A Class that extends ActiveModel::Naming

It received #{model_class.inspect}
EOM
  end

  stubs = stubs.reverse_merge(:id => next_id)
  stubs = stubs.reverse_merge(:persisted? => !!stubs[:id])
  stubs = stubs.reverse_merge(:destroyed? => false)
  stubs = stubs.reverse_merge(:marked_for_destruction? => false)

  mock("#{model_class.name}_#{stubs[:id]}", stubs).tap do |m|
    m.extend ActiveModelInstanceMethods
    m.singleton_class.__send__ :include, ActiveModel::Conversion
    m.singleton_class.__send__ :include, ActiveModel::Validations
    if defined?(ActiveRecord)
      m.extend ActiveRecordInstanceMethods
      [:save, :update_attributes].each do |key|
        if stubs[key] == false
          m.errors.stub(:empty?) { false }
        end
      end
    end
    m.__send__(:__mock_proxy).instance_eval(<<-CODE, __FILE__, __LINE__)
      def @object.is_a?(other)
        #{model_class}.ancestors.include?(other)
      end
      def @object.kind_of?(other)
        #{model_class}.ancestors.include?(other)
      end
      def @object.instance_of?(other)
        other == #{model_class}
      end
      def @object.respond_to?(method_name)
        #{model_class}.respond_to?(:column_names) && #{model_class}.column_names.include?(method_name.to_s) || super
      end
      def @object.class
        #{model_class}
      end
      def @object.to_s
        "#{model_class.name}_#{to_param}"
      end
    CODE
    yield m if block_given?
  end
end

#stub_model(model_class, stubs = {}) ⇒ Object

:call-seq:

stub_model(Model)
stub_model(Model).as_new_record
stub_model(Model, hash_of_stubs)
stub_model(Model, instance_variable_name, hash_of_stubs)

Creates an instance of Model with to_param stubbed using a generated value that is unique to each object.. If Model is an ActiveRecord model, it is prohibited from accessing the database*.

For each key in hash_of_stubs, if the model has a matching attribute (determined by asking it) are simply assigned the submitted values. If the model does not have a matching attribute, the key/value pair is assigned as a stub return value using RSpec’s mocking/stubbing framework.

persisted? is overridden to return the result of !id.nil? This means that by default persisted? will return true. If you want the object to behave as a new record, sending it as_new_record will set the id to nil. You can also explicitly set :id => nil, in which case persisted? will return false, but using as_new_record makes the example a bit more descriptive.

While you can use stub_model in any example (model, view, controller, helper), it is especially useful in view examples, which are inherently more state-based than interaction-based.

Examples

stub_model(Person)
stub_model(Person).as_new_record
stub_model(Person, :to_param => 37)
stub_model(Person) do |person|
  person.first_name = "David"
end



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# File 'lib/rspec/rails/mocks.rb', line 179

def stub_model(model_class, stubs={})
  model_class.new.tap do |m|
    m.extend ActiveModelStubExtensions
    if defined?(ActiveRecord) && model_class < ActiveRecord::Base
      m.extend ActiveRecordStubExtensions
      primary_key = model_class.primary_key.to_sym
      stubs = stubs.reverse_merge(primary_key => next_id)
      stubs = stubs.reverse_merge(:persisted? => !!stubs[primary_key])
    else
      stubs = stubs.reverse_merge(:id => next_id)
      stubs = stubs.reverse_merge(:persisted? => !!stubs[:id])
    end
    stubs.each do |k,v|
      m.__send__("#{k}=", stubs.delete(k)) if m.respond_to?("#{k}=")
    end
    m.stub(stubs)
    yield m if block_given?
  end
end