rspecでrender_viewsするとエラーが発生してしまう。

rspecでコントローラーのテストを書いています。
検索機能つきの一覧表示画面のテストでrender_viewsを使って正しく表示されることをテストしたいです。
"条件指定のパラメータがある時"内でバリデーションエラーの文言がviewに含まれているかを確認したいです。
またcontroller内で入力チェックを行なっており、問題があった場合は@error配列にエラーメッセージを入れておくことでバリデーションを実装しているのでそれを確認できてもいいかとおもています。

テストコードを書くのが初めてでほとんど分かっていない状態なので、質問の仕方が正しいかどうかもわからないのですがよろしくお願いします。

ruby
1コントローラーのindex
2
3def index     
4  @errors = [] 
5  param_check
6  if @errors.any?
7    category_list
8    @info = search_info
9    render :index
10  end
11  @info = search_info
12end

ruby
1テストコード
2
3require 'rails_helper'
4RSpec.describe InfoController, type: :controller do
5
6  describe 'Get #index' do
7    render_views
8    before do
9      get :index
10    end
11
12    context "デフォルト(条件指定のパラメータがない場合)" do
13      it "正常に動作しているか" do
14        expect(response.status).to eq(200)
15      end
16      it "returns http success" do
17        expect(response).to have_http_status(:success)
18      end
19      it "正しくレンダリングされているか" do
20        expect(response).to render_template(:index)
21      end
22      it "正しく表示されているか" do
23        expect(response).to render_template(:index)
24      end
25    end
26    context "条件指定のパラメータがある場合" do
27      it "正常な値" do
28        get :index, params: {id: 1 ,title: "test" ,date: "2017/12/12"}
29
30      end
31      it "不正な値" do
32        get :index, params: { id: "aaa" }
33
34      end
35    end
36  end
37  
38end
39

発生するエラー

InfoController Get #index デフォルト(条件指定のパラメータがない場合) 正しくレンダリングされているか
     Failure/Error: get :index

     ActionView::Template::Error:
       File to import not found or unreadable: ../bootstrap/dist/css/bootstrap.min.
     # (sass):17
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/import_node.rb:67:in `rescue in import'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/import_node.rb:45:in `import'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/import_node.rb:28:in `imported_file'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/import_node.rb:37:in `css_import?'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/visitors/perform.rb:314:in `visit_import'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/visitors/base.rb:36:in `visit'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/visitors/perform.rb:162:in `block in visit'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/stack.rb:79:in `block in with_base'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/stack.rb:135:in `with_frame'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/stack.rb:79:in `with_base'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/visitors/perform.rb:162:in `visit'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/visitors/base.rb:52:in `block in visit_children'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/visitors/base.rb:52:in `map'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/visitors/base.rb:52:in `visit_children'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/visitors/perform.rb:171:in `block in visit_children'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/visitors/perform.rb:183:in `with_environment'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/visitors/perform.rb:170:in `visit_children'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/visitors/base.rb:36:in `block in visit'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/visitors/perform.rb:190:in `visit_root'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/visitors/base.rb:36:in `visit'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/visitors/perform.rb:161:in `visit'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/visitors/perform.rb:10:in `visit'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/root_node.rb:36:in `css_tree'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/root_node.rb:20:in `render'
     # /usr/local/bundle/gems/sass-3.5.3/lib/sass/engine.rb:290:in `render'
     # /usr/local/bundle/gems/sprockets-3.7.1/lib/sprockets/sass_compressor.rb:48:in `call'
     # /usr/local/bundle/gems/sprockets-3.7.1/lib/sprockets/sass_compressor.rb:28:in `call'
     # /usr/local/bundle/gems/sprockets-3.7.1/lib/sprockets/processor_utils.rb:75:in `call_processor'
     # /usr/local/bundle/gems/sprockets-3.7.1/lib/sprockets/processor_utils.rb:57:in `block in call_processors'
     # /usr/local/bundle/gems/sprockets-3.7.1/lib/sprockets/processor_utils.rb:56:in `reverse_each'
     # /usr/local/bundle/gems/sprockets-3.7.1/lib/sprockets/processor_utils.rb:56:in `call_processors'
     # /usr/local/bundle/gems/sprockets-3.7.1/lib/sprockets/loader.rb:134:in `load_from_unloaded'
     # /usr/local/bundle/gems/sprockets-3.7.1/lib/sprockets/loader.rb:60:in `block in load'
     # /usr/local/bundle/gems/sprockets-3.7.1/lib/sprockets/loader.rb:317:in `fetch_asset_from_dependency_cache'
     # /usr/local/bundle/gems/sprockets-3.7.1/lib/sprockets/loader.rb:44:in `load'
     # /usr/local/bundle/gems/sprockets-3.7.1/lib/sprockets/cached_environment.rb:20:in `block in initialize'
     # /usr/local/bundle/gems/sprockets-3.7.1/lib/sprockets/cached_environment.rb:47:in `load'
     # /usr/local/bundle/gems/sprockets-3.7.1/lib/sprockets/base.rb:66:in `find_asset'
     # /usr/local/bundle/gems/sprockets-3.7.1/lib/sprockets/base.rb:92:in `[]'
     # /usr/local/bundle/gems/sprockets-rails-3.2.1/lib/sprockets/rails/helper.rb:355:in `find_asset'
     # /usr/local/bundle/gems/sprockets-rails-3.2.1/lib/sprockets/rails/helper.rb:336:in `digest_path'
     # /usr/local/bundle/gems/sprockets-rails-3.2.1/lib/sprockets/rails/helper.rb:325:in `asset_path'
     # /usr/local/bundle/gems/sprockets-rails-3.2.1/lib/sprockets/rails/helper.rb:102:in `block in resolve_asset_path'
     # /usr/local/bundle/gems/sprockets-rails-3.2.1/lib/sprockets/rails/helper.rb:242:in `block in resolve_asset'
     # /usr/local/bundle/gems/sprockets-rails-3.2.1/lib/sprockets/rails/helper.rb:241:in `each'
     # /usr/local/bundle/gems/sprockets-rails-3.2.1/lib/sprockets/rails/helper.rb:241:in `detect'
     # /usr/local/bundle/gems/sprockets-rails-3.2.1/lib/sprockets/rails/helper.rb:241:in `resolve_asset'
     # /usr/local/bundle/gems/sprockets-rails-3.2.1/lib/sprockets/rails/helper.rb:101:in `resolve_asset_path'
     # /usr/local/bundle/gems/sprockets-rails-3.2.1/lib/sprockets/rails/helper.rb:79:in `compute_asset_path'
     # /usr/local/bundle/gems/sprockets-rails-3.2.1/lib/sprockets/rails/helper.rb:185:in `block in stylesheet_link_tag'
     # /usr/local/bundle/gems/sprockets-rails-3.2.1/lib/sprockets/rails/helper.rb:183:in `map'
     # /usr/local/bundle/gems/sprockets-rails-3.2.1/lib/sprockets/rails/helper.rb:183:in `stylesheet_link_tag'
     # ./admin/app/views/layouts/admin/application.html.erb:5:in `_admin_app_views_layouts_admin_application_html_erb___1010548273086144572_41218100'
     # /usr/local/bundle/gems/yuba-0.0.2/lib/yuba/rendering.rb:6:in `render'
     # /usr/local/bundle/gems/rails-controller-testing-1.0.2/lib/rails/controller/testing/template_assertions.rb:61:in `process'
     # /usr/local/bundle/gems/rails-controller-testing-1.0.2/lib/rails/controller/testing/integration.rb:12:in `block (2 levels) in <module:Integration>'
     # ./spec/controllers/notifications_controller_spec.rb:8:in `block (3 levels) in <top (required)>'
     # ------------------
     # --- Caused by: ---
     # Sass::SyntaxError:
     #   File to import not found or unreadable: ../bootstrap/dist/css/bootstrap.min.
     #   /usr/local/bundle/gems/sass-3.5.3/lib/sass/tree/import_node.rb:65:in `import'