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 mock object instance for a string_or_model_class with common methods stubbed out. Additional methods may be easily stubbed (via add_stubs) if stubs is passed.

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 40

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 "The mock_model method can only accept as its first argument:\n  * A String representing a Class that does not exist\n  * A String representing a Class that extends ActiveModel::Naming\n  * A Class that extends ActiveModel::Naming\n\nIt received \#{model_class.inspect}\n"
  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 RSpec::Rails::using_active_record?
      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("      def @object.is_a?(other)\n        \#{model_class}.ancestors.include?(other)\n      end\n      def @object.kind_of?(other)\n        \#{model_class}.ancestors.include?(other)\n      end\n      def @object.instance_of?(other)\n        other == \#{model_class}\n      end\n      def @object.respond_to?(method_name)\n        \#{model_class}.respond_to?(:column_names) && \#{model_class}.column_names.include?(method_name.to_s) || super\n      end\n      def @object.class\n        \#{model_class}\n      end\n      def @object.to_s\n        \"\#{model_class.name}_\#{to_param}\"\n      end\n    CODE\n    yield m if block_given?\n  end\nend\n", __FILE__, __LINE__)

#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.

new_record? is overridden to return the result of id.nil? This means that by default new_record? will return false. 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 new_record? will return true, 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.

Database Independence

stub_model does not make your examples entirely database-independent. It does not stop the model class itself from loading up its columns from the database. It just prevents data access from the object itself. To completely decouple from the database, take a look at libraries like unit_record or NullDB.

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 175

def stub_model(model_class, stubs={})
  model_class.new.tap do |m|
    m.extend ActiveModelStubExtensions
    if RSpec::Rails::using_active_record? && 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