def create
  @firm = FirmForm.new(Firm.new(firm_params))

  if @firm.validate(firm_params) && @firm.save!
    redirect_to firms_path, notice: 'Фирма добавлена.'
  else
    render :new
  end
end

describe "POST 'create'" do
  let(:firm_double) { double('firm_double') }

  context 'when firm was created' do
    before(:each) do
      FirmForm.stub(:new).and_return(firm_double)
      firm_double.stub(:validate).and_return(true)
      firm_double.stub(:save!).and_return(true)
    end

    it 'creates a new firm' do
      do_request
      expect(assigns(:firm)).to be(firm_double)
    end

    it 'redirects to the correct url' do
      do_request
      expect(response).to redirect_to firms_path
    end

    it 'add message to notice' do
      do_request
      expect(flash[:notice]).to eq('Фирма добавлена.')
    end
  end

  context "when firm wasn't created" do
    before(:each) do
      FirmForm.stub(:new).and_return(firm_double)
      firm_double.stub(:validate).and_return(true)
      firm_double.stub(:save!).and_return(false)
    end

    it 'should render new' do
      do_request
      get :new
      expect(response).to render_template('new')
    end
  end