How to write RSpec test for the following code

I have the functionality of my code working correctly, but need to create an RSpec test that covers it. My code in movies_controller.rb:

def find_with_same_director
  @movie = Movie.find(params[:id])
  @movies, check_info = Movie.find_with_same_director(params[:id])
  if check_info
    flash[:notice] = "'#{@movie.title}' has no director info"
    redirect_to movies_path
  end
end

The find_with_same_director function in the model, movie.rb:

def self.find_with_same_director(id)
  movie = self.find(id)
  if !movie.director.blank?
    movies = self.where(:director => movie.director).where.not(:id => movie.id)
    return movies, false
  else
    return [], true
  end
end

I am trying to write tests that covers the click on the "Find With Same Director" link that calls the function, when the movie that was clicked has a director to show, and when it doesn't. I've written the following tests in movies_controller_spec.rb for each so far:

describe 'find_with_same_director' do
  it 'should call the find_with_same_director model method' do
    expect(Movie).to receive(:find_with_same_director).with(params[:id])
    get :find_with_same_director, id: movie.id
  end

  context 'movie has a director' do
    let!(:movie1) {FactoryGirl.create(:movie, :director => movie.director)}
    it do
      get :find_with_same_director, id: movie1.id
      expect(response).to redirect_to(movie_path(movie1.id))
    end
  end

  context 'movie has no director' do
    let!(:movie1) { FactoryGirl.create(:movie, :director => nil)}
    it "should redirect to root" do
      get :find_with_same_director, id: movie1.id
      expect(response).to redirect_to(root_url)
    end
  end
end

I have spent hours working on these tests and while they are "covering" the lines when i check the report, they return fails. This means I wrote them incorrectly. I want to modify these tests to accurately represent what my controller code is doing and I would really appreciate some help with that. If you're feeling down to it I would also appreciate if you gave advice on writing the rspec test code for the model movie.rb file as well.