11.6 练习

最后更新于:2022-04-01 22:30:31

# 11.6 练习 电子书中有练习的答案,如果想阅读参考答案,请[购买电子书](http://railstutorial-china.org/#purchase)。 避免练习和正文冲突的方法参见[第 3 章练习](chapter3.html#mostly-static-pages-exercises)中的说明。 1. 重构首页视图,把 `if-else` 语句的两个分支分别放到单独的局部视图中。 2. 为侧边栏中的微博数量编写测试(还要检查使用了正确的单复数形式)。可以参照[代码清单 11.67](#listing-sidebar-micropost-count)。 3. 以[代码清单 11.68](#listing-image-upload-test) 为模板,为 [11.4 节](#micropost-images)的图片上传程序编写测试。测试之前,要在固件文件夹中放一个图片(例如,可以执行 `cp app/assets/http://railstutorial-china.org/book/images/rails.png test/fixtures/` 命令)。(如果使用 Git,建议你更新 `.gitignore` 文件,如[代码清单 11.69](#listing-gitignore-uploads) 所示。)为了避免出现难以理解的错误,还要配置 CarrierWave,在测试中不调整图片的尺寸。方法是创建一个初始化脚本,写入[代码清单 11.70](#listing-skip-resize-initializer) 中的内容。[代码清单 11.68](#listing-image-upload-test) 中添加的几个断言,检查首页有没有文件上传字段,以及成功提交表单后有没有正确设定 `picture` 属性的值。注意,在测试中上传固件中的文件使用的是专门的 `fixture_file_upload` 方法。[[17](#fn-17)]提示:为了检查 `picture` 属性的值,可以使用 [10.1.4 节](chapter10.html#activation-test-and-refactoring)介绍的 `assigns` 方法,在提交成功后获取 `create` 动作中的 `@micropost` 变量。 ##### 代码清单 11.67:侧边栏中微博数量的测试模板 test/integration/microposts_interface_test.rb ``` require 'test_helper' class MicropostInterfaceTest < ActionDispatch::IntegrationTest def setup @user = users(:michael) end . . . test "micropost sidebar count" do log_in_as(@user) get root_path assert_match "#{FILL_IN} microposts", response.body # 这个用户没有发布微博 other_user = users(:malory) log_in_as(other_user) get root_path assert_match "0 microposts", response.body other_user.microposts.create!(content: "A micropost") get root_path assert_match FILL_IN, response.body end end ``` ##### 代码清单 11.68:图片上传测试的模板 test/integration/microposts_interface_test.rb ``` require 'test_helper' class MicropostInterfaceTest < ActionDispatch::IntegrationTest def setup @user = users(:michael) end test "micropost interface" do log_in_as(@user) get root_path assert_select 'div.pagination' assert_select 'input[type=FILL_IN]' # 无效提交 post microposts_path, micropost: { content: "" } assert_select 'div#error_explanation' # 有效提交 content = "This micropost really ties the room together" picture = fixture_file_upload('test/fixtures/rails.png', 'image/png') assert_difference 'Micropost.count', 1 do post microposts_path, micropost: { content: content, picture: FILL_IN } end assert FILL_IN.picture? follow_redirect! assert_match content, response.body # 删除一篇微博 assert_select 'a', 'delete' first_micropost = @user.microposts.paginate(page: 1).first assert_difference 'Micropost.count', -1 do delete micropost_path(first_micropost) end # 访问另一个用户的资料页面 get user_path(users(:archer)) assert_select 'a', { text: 'delete', count: 0 } end . . . end ``` ##### 代码清单 11.69:在 `.gitignore` 中添加存储上传图片的文件夹 ``` # See https://help.github.com/articles/ignoring-files for more about ignoring # files. # # If you find yourself ignoring temporary files generated by your text editor # or operating system, you probably want to add a global ignore instead: # git config --global core.excludesfile '~/.gitignore_global' # Ignore bundler config. /.bundle # Ignore the default SQLite database. /db/*.sqlite3 /db/*.sqlite3-journal # Ignore all logfiles and tempfiles. /log/*.log /tmp # Ignore Spring files. /spring/*.pid # Ignore uploaded test images. /public/uploads ``` ##### 代码清单 11.70:一个初始化脚本,在测试中不调整图片的尺寸 config/initializers/skip_image_resizing.rb ``` if Rails.env.test? CarrierWave.configure do |config| config.enable_processing = false end end ```
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