如何在 Capybara 和 RSpec 中测试 CSV 文件下载？答案

【问题标题】：How to test CSV file download in Capybara and RSpec?如何在 Capybara 和 RSpec 中测试 CSV 文件下载？
【发布时间】：2015-06-01 06:59:20
【问题描述】：

控制器中有以下内容：

respond_to do |format|
  format.csv  { send_data as_csv, type:'text/csv' }
end

在规范中：

click_link 'Download CSV'
page.driver.browser.switch_to.alert.accept

expect( page ).to have_content csv_data

但这不起作用：

Failure/Error: page.driver.browser.switch_to.alert.accept
Selenium::WebDriver::Error::NoAlertPresentError: No alert is present

我看到“保存文件”对话框显示，但显然它不是“警告”对话框。

如何点击确定让Capybara查看数据？

【问题讨论】：

标签： ruby-on-rails ruby selenium rspec capybara

【解决方案1】：

改编自CollectiveIdea 和其他来源。

适用于 OSX。火狐 34.0.5

规格：

  describe 'Download CSV' do
    let( :submission_email ){ 'foo@example.com' }
    let( :email_csv ){ "id,email,created_at\n1,#{ submission_email }," }

    specify do
      visit '/emails'
      expect( page ).to have_content 'Email Submissions'

      click_on 'Download CSV'

      expect( DownloadHelpers::download_content ).to include email_csv
    end
  end

规范助手：

require 'shared/download_helper'

Capybara.register_driver :selenium do |app|
  profile = Selenium::WebDriver::Firefox::Profile.new
  profile['browser.download.dir'] = DownloadHelpers::PATH.to_s
  profile['browser.download.folderList'] = 2

  # Suppress "open with" dialog
  profile['browser.helperApps.neverAsk.saveToDisk'] = 'text/csv'
  Capybara::Selenium::Driver.new(app, :browser => :firefox, :profile => profile)
end

config.before( :each ) do
    DownloadHelpers::clear_downloads
end

shared/download_helper.rb：

module DownloadHelpers
  TIMEOUT = 1
  PATH    = Rails.root.join("tmp/downloads")

  extend self

  def downloads
    Dir[PATH.join("*")]
  end

  def download
    downloads.first
  end

  def download_content
    wait_for_download
    File.read(download)
  end

  def wait_for_download
    Timeout.timeout(TIMEOUT) do
      sleep 0.1 until downloaded?
    end
  end

  def downloaded?
    !downloading? && downloads.any?
  end

  def downloading?
    downloads.grep(/\.part$/).any?
  end

  def clear_downloads
    FileUtils.rm_f(downloads)
  end
end

【讨论】：

你为什么使用：let( :submission_email ){ 'foo@example.com' } let( :email_csv ){ "id,email,created_at\n1,#{ submit_email }," }
我得到：无法加载这样的文件 -- shared/download_helper.rb (LoadError) 当 spec_helper 运行时需要 'shared/download_helper' 行。 download_helper.rb 在正确的位置。
@ChaosPredictor 将该文件放入 spec/shared/download_helper.rb
由于现在不推荐将配置文件直接传递给驱动程序，因此这里有一种使用选项设置下载位置的方法：stackoverflow.com/questions/37391879/…

【解决方案2】：

如果您使用rack_test 驱动程序（无javascript/无浏览器），我找到了另一种方法：

DOWNLOAD_CACHE_PATH = Rails.root.join("tmp/downloaded_file").to_s

setup do
  File.delete(DOWNLOAD_CACHE_PATH)
end

test "download file" do
  visit download_file_path

  # simulate file download
  File.write(DOWNLOAD_CACHE_PATH, page.body)

  csv = CSV.open(DOWNLOAD_CACHE_PATH)
  # assert something on the csv data
end

【讨论】：

我没有其他建议，但这是一个简单且有效的解决方案！
听起来这个答案可能会通过使用TempFile来改进？

【解决方案3】：

我尝试实现类似的东西并花费大量时间。最后我有一些解决方案，也许它也适合你。

宝石文件：

#source 'https://rubygems.org'

gem 'rails',                   '4.2.2'
gem 'bcrypt',                  '3.1.7'
gem 'bootstrap-sass',          '3.2.0.0'
gem 'faker',                   '1.4.2'
gem 'carrierwave',             '0.10.0'
gem 'mini_magick',             '3.8.0'
gem 'fog',                     '1.36.0'
gem 'will_paginate',           '3.0.7'
gem 'bootstrap-will_paginate', '0.0.10'
gem 'sass-rails',              '5.0.2'
gem 'uglifier',                '2.5.3'
gem 'coffee-rails',            '4.1.0'
gem 'jquery-rails',            '4.0.3'
gem 'turbolinks',              '2.3.0'
gem 'jbuilder',                '2.2.3'
gem 'sdoc',                    '0.4.0', group: :doc
gem 'rename'
gem 'sprockets',                             '3.6.3'
gem 'responders',           '~> 2.0' 
gem 'inherited_resources'

group :development, :test do
  gem 'sqlite3',     '1.3.9'
  gem 'byebug',      '3.4.0'
  gem 'web-console', '2.0.0.beta3'
  gem 'spring',      '1.1.3'
end

group :test do
  gem 'minitest-reporters', '1.0.5'
  gem 'mini_backtrace',     '0.1.3'
  gem 'guard-minitest',     '2.3.1'
    gem 'capybara',           '2.8.1'
    gem 'rspec',              '3.5.0'
    gem 'rspec-rails',     '~> 3.4'
    gem 'cucumber-rails', :require => false
    gem 'shoulda-matchers', '~> 3.0', require: false
    gem 'database_cleaner'
    gem 'factory_girl_rails', '~> 4.5.0'
end

spec/rails_helper.rb

ENV['RAILS_ENV'] ||= 'test'
require File.expand_path('../../config/environment', __FILE__)
abort("The Rails environment is running in production mode!") if Rails.env.production?
require 'spec_helper'
require 'rspec/rails'

require 'shoulda/matchers'

Shoulda::Matchers.configure do |config|
  config.integrate do |with|
    with.test_framework :rspec
    with.library :rails
  end
end

config.use_transactional_fixtures = false

ActiveRecord::Migration.maintain_test_schema!

RSpec.configure do |config|
  config.fixture_path = "#{::Rails.root}/spec/fixtures"

  config.use_transactional_fixtures = true

  config.infer_spec_type_from_file_location!

  config.filter_rails_from_backtrace!
end

spec/spec_helper.rb

ENV["RAILS_ENV"] ||= 'test'
require File.expand_path("../../config/environment", __FILE__)
require 'rspec/rails'

require 'capybara/rspec'
require 'capybara/rails'

require 'download_helper'

Capybara.register_driver :selenium do |app|
  profile = Selenium::WebDriver::Firefox::Profile.new
  profile['browser.download.dir'] = DownloadHelpers::PATH.to_s
  profile['browser.download.folderList'] = 2

  profile['browser.helperApps.neverAsk.saveToDisk'] = 'text/csv'
  Capybara::Selenium::Driver.new(app, :browser => :firefox, :profile => profile)
end


RSpec.configure do |config|
  config.expect_with :rspec do |expectations|
    expectations.include_chain_clauses_in_custom_matcher_descriptions = true
  end

  config.mock_with :rspec do |mocks|
    mocks.verify_partial_doubles = true
  end

  config.shared_context_metadata_behavior = :apply_to_host_groups

    config.include Capybara::DSL


=begin
  config.filter_run_when_matching :focus

  config.example_status_persistence_file_path = "spec/examples.txt"

  config.disable_monkey_patching!

  if config.files_to_run.one?
    config.default_formatter = 'doc'
  end

  config.profile_examples = 10

  config.order = :random

  Kernel.srand config.seed
=end
end

test/test_helper.rb

ENV['RAILS_ENV'] ||= 'test'
require File.expand_path('../../config/environment', __FILE__)
require 'rails/test_help'
require 'capybara/rails'

class ActiveSupport::TestCase
  # Setup all fixtures in test/fixtures/*.yml for all tests in alphabetical order.
  fixtures :all
    include ApplicationHelper

    def is_logged_in?
        !session[:user_id].nil?
    end

    # Logs in a test user.
    def log_in_as(user, options = {})
        password = options[:password] || 'password'
        remember_me = options[:remember_me] || '1'
        if integration_test?
            post login_path, session: { email:user.email, password: password, remember_me: remember_me }
        else
            session[:user_id] = user.id
        end
    end

    private

        # Returns true inside an integration test.
        def integration_test?
            defined?(post_via_redirect)
        end

end

class ActionDispatch::IntegrationTest
  # Make the Capybara DSL available in all integration tests
  include Capybara::DSL

  # Reset sessions and driver between tests
  # Use super wherever this method is redefined in your individual test classes
  def teardown
    Capybara.reset_sessions!
    Capybara.use_default_driver
  end
end

spec/download_helper.rb

module DownloadHelpers
  TIMEOUT = 1
  PATH    = Rails.root.join("tmp/downloads")

  extend self

  def downloads
    Dir[PATH.join("*")]
  end

  def download
    downloads.first
  end

  def download_content
    wait_for_download
    File.read(download)
  end

  def wait_for_download
    Timeout.timeout(TIMEOUT) do
      sleep 0.1 until downloaded?
    end
  end

  def downloaded?
    !downloading? && downloads.any?
  end

  def downloading?
    downloads.grep(/\.part$/).any?
  end

  def clear_downloads
    FileUtils.rm_f(downloads)
  end
end

spec/mpodels/spec.rb

  describe 'Download file' do

    specify do
      visit '/createfile'

      click_on 'create file'

            page.response_headers['Content-Type'].should == "text/csv"
            header = page.response_headers['Content-Disposition']
            header.should match /^attachment/
            header.should match /filename=\"temp.csv\"$/
       end
    end

【讨论】：

【解决方案4】：

根据浏览器的不同，您需要该浏览器的配置文件，我建议禁用要求保存在该配置文件中的属性。

【讨论】：

【解决方案5】：

@b-seven 非常感谢！

我制作了自己的 download_helper.rb 版本，也许它对某人有用。

spec/support/helpers/download_helpers.rb

module DownloadHelpers
  DOWNLOAD_DIR = 'tmp/capybara_downloads'
  DOWNLOAD_PATH = ::Rails.root.join(DOWNLOAD_DIR)

  def clear_downloads
    FileUtils.rm_f(downloads)
  end

  def downloads
    Dir[DOWNLOAD_PATH.join('*')]
  end

  def download_file(filename)
    wait_for_download(filename)
    File.read(::Rails.root.join(DOWNLOAD_DIR, filename))
  end

  def wait_for_download(filename)
    Timeout.timeout(Capybara.default_max_wait_time,
                    Timeout::Error,
                    "File download timeout! File: #{filename}") do
      sleep 0.1 until File.exist?(::Rails.root.join(DOWNLOAD_DIR, filename))
  end
end

结束

【讨论】：