Not A Mock¶ ↑

A cleaner and DRYer alternative to mocking and stubbing with RSpec.

notahat.com/not_a_mock

A Quick Introduction¶ ↑

Mocking (Not)¶ ↑

When you’re setting up for a spec, you can ask that method calls on an object be recorded:

object.track_methods(:name, :length)

Once your code has run, you can make assertions about what methods were called, what arguments they took, their results, etc.

object.should have_received(:length).without_args.and_returned(42)
object.should have_received(:name).twice

See NotAMock::Matchers for an explanation of the available assertions, plus Object#track_methods and Object#untrack_methods.

Stubbing¶ ↑

Stubbing Methods¶ ↑

You can replace a method on an object with a stub version like this:

object.stub_method(:method => return_value)

Any call to method after this will return return_value without invoking the method’s usual code.

Calls to stub methods are recorded as if you had called track_methods on them, so you can make assertions about them as shown above.

See Object#stub_methods, Object#unstub_methods.

Stubbing Objects¶ ↑

You can also replace an entire object with a stub version like this:

my_object = MyClass.stub_instance(:method_a => return_value, :method_b => return_value, ...)

The returned my_object is a stub instance of MyClass with the given methods defined to provide the corresponding return values.

See Object.stub_instance.

Stubbing ActiveRecord Instances¶ ↑

When you call stub_instance on an ActiveRecord::Base subclass, Not A Mock automatically provides an id method and generates an id for the object.

Installation¶ ↑

(The following describes using NotAMock with Rails. It should also be possible to use it outside of Rails, but I haven’t tried it.)

First, install the rspec and rspec_on_rails plugins:

ruby script/plugin install http://rspec.rubyforge.org/svn/tags/CURRENT/rspec
ruby script/plugin install http://rspec.rubyforge.org/svn/tags/CURRENT/rspec_on_rails
ruby script/generate rspec

(See rspec.info/documentation/rails/install.html for more details.)

Second, install the not_a_mock plugin:

ruby script/plugin install git://github.com/notahat/not_a_mock.git

Finally, add the following to your project’s spec/spec_helper.rb:

config.mock_with NotAMock::RspecMockFrameworkAdapter

Contributing¶ ↑

Send bugs, patches, and suggestions to Pete Yandell (pete@notahat.com)

Thanks to Pat Allan and Steve Hayes for contributing patches.