Question

My controller action:

 def single
    final_static_matrix = Single.final_static_matrix(average_static_matrix, params[:priorities])
   
     ...

  end

In my lib/single.rb:

module Single
  def self.final_static_matrix(average_static_matrix = {}, priorities = {})
    final_static_matrix = Hash.new

    for i in 0..average_static_matrix.length-1
      final_static_matrix[i.to_s] = average_static_matrix*priorities[i.to_s]
    end

    final_static_matrix
  end
end

In my controller_spec.rb:

it "should be successful" do
  get :single, :id => 1
  priorities = {"0" => "1"}
  matrix = {"0" => "3"}
  Single.final_static_matrix(matrix, priorities)
  response.should be_success
end

1. How I should call the function from lib/ directory?
2. How be better if i will write tests in controller file or create something like single_spec.rb?

Answer 1

What I would do: inside the controller-spec, I would test that the method gets called:

describe "GET :single" do
  it "succeeds" do
    Single.should_receive(:final_static_matrix).and_return('something')

    get :single, :id => 1
  end
end

and inside spec/lib/single_spec.rb you test that the final_static_matrix acts as expected.

You can check the documentation of rspec2 here.