如何在应用程序控制器中测试方法?我的方法使其他测试随机崩溃

Question

我在应用程序控制器中有一个简单的方法：

class ApplicationController < ActionController::Base
  def filename_for_export(project, type, format = nil)
    buffer = "#{project.customer} - #{project.name} (#{type}, #{t 'org.name'}, #{Date.today.to_s :db})"
    buffer += ".#{format}" if format
    buffer
  end
end

我有以下测试：

describe ApplicationController do
  describe '#filename_for_export' do
    before { @controller = ApplicationController.new }
    it 'returns a good human readable filename' do
      project = create(:project)
      result = @controller.instance_eval{ filename_for_export(project, 'Audit') }
      expect(result).to eq 'Project test customer - Project test name (Audit, Access for all, 2015-06-15)'
    end
  end
end

一切都很好。然后我添加了另一个测试：

it 'appends a format extension if given' do
  project = create(:project)
  result = @controller.instance_eval{ filename_for_export(project, 'Audit', 'pdf') }
  expect(result).to eq 'Project test customer - Project test name (Audit, Access for all, 2015-06-15).pdf'
end

工作也很好。但有趣的是，第二次测试似乎打破了一些让许多其他规格随机失败的东西：

...
rspec ./spec/features/file_upload_spec.rb:18 # File upload displays a preview of an uploaded file
rspec ./spec/features/file_upload_spec.rb:4 # File upload allows to upload a file
rspec ./spec/features/file_upload_spec.rb:27 # File upload displays a preview of an uploaded file (from the temporary cache) after a re-display of the form
rspec ./spec/features/file_upload_spec.rb:60 # File upload allows to remove a file
rspec ./spec/features/markdown_spec.rb:4 # Markdown uses Pandoc as converter for inline markdown
rspec ./spec/features/users/destroy_spec.rb:22 # Deleting user signed in as admin grants permission to delete other user
rspec ./spec/features/success_criteria/show_spec.rb:6 # Showing success criterion displays a success criterion
rspec ./spec/features/boilerplate_originals/edit_spec.rb:11 # Editing boilerplate grants permission to edit a boilerplate
...

总是有另一套规格失败（我想是订单问题），但我不知道是什么破坏了东西？第二个规范与第一个规范没有任何不同，那么它会打破什么呢？

Answer 1

如果必须这样做，可以使用Rspec的匿名控制器，如所述

 ...
 controller do
   def index
     project = create(:project)
     render json: filename_for_export(project, 'Audit', 'pdf')
   end
 end
 it 'appends a format extension if given' do
   get :index
   expect(JSON.parse(response.body)).to eq 'Project test customer - Project test name (Audit, Access for all, 2015-06-15).pdf'
 end

然而，我强烈建议您简单地将此方法提取到一个普通的旧ruby对象中，并将其作为单元测试进行隔离测试。您为"常规"控制器方法编写的请求规范应该涵盖集成。