I wish this would just work...

projects_controller_spec.rb

require 'spec_helper'

describe ProjectsController do

  let(:project) { double(:project) }
  let(:projects) { [project] }

  describe 'GET show' do
    let(:params) { { :id => 1, :format => :json } }

    before { Project.should_receive(:find).with(1).and_return(project) }

    it { should assign_to(:project).with(project) }
    it { should respond_with(project) }
  end

end