RSpec - mocking a class method

Question

I'm trying to mock a class method with rspec:

lib/db.rb

class Db
  def self.list(options)
    Db::Payload.list(options)
  end
end

lib/db/payload.rb

class Db::Payload
  def self.list(options={})
  end
end

In my spec, I'm trying to setup the expectation Db::Payload.list will be called when I call Db.list:

require 'db/payload'

describe Db do
  before(:each) do
    @options = {}
    Db::Payload.should_receive(:list).with(@options)
  end

  it 'should build the LIST payload' do
    Db.list(@options)
  end
end

The problem is that I am always receiving the following error:

undefined method `should_receive' for Db::Payload:Class

Any help understanding this error would be most appreciated :-)

Answer 1

Your spec_helper.rb should have something like this:

Spec::Runner.configure do |config|
  # == Mock Framework
  #
  # RSpec uses its own mocking framework by default. If you prefer to
  # use mocha, flexmock or RR, uncomment the appropriate line:
  #
  # config.mock_with :mocha
  # config.mock_with :flexmock
  # config.mock_with :rr
end

The default argument is config.mock_with :rspec which enables the should_receive method. If you're using Mocha, for example, the equivalent is expects, so make sure you're using the right mocking framework.