Rails + Rspec：数据库清洁器 gem 不起作用

Question

我需要一些关于如何让数据库清理器为我的 Rails 应用程序工作的指导。每次测试的记录 ID 都在不断增加，并且不会被清除。

我已经设置了一个测试来检查数据库清理器是否工作并且它失败了。

spec/models/concerns/database_cleaner_test.rb

require 'rails_helper'

describe "db_cleaner" do

    let!(:article) { FactoryGirl.create(:article) }

    it "first test" do
      expect(Article.all.count).to eq(1)
      expect(Article.last.id).to eq(1)
    end

    it "should clean db" do
      expect(Article.all.count).to eq(1)
      expect(Article.last.id).to eq(1)
    end

end

失败：

  1) db_cleaner should clean db
     Failure/Error: expect(Article.last.id).to eq(1)

       expected: 1
            got: 2

       (compared using ==)

设置：

gem 'rails', '~> 5.1.2'
gem 'pg', '~> 0.18'

group :development, :test do
  gem 'rspec-rails', '~> 3.6', '>= 3.6.1'
  gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
  gem 'capybara', '2.7.1'
  gem 'capybara-webkit'
  gem 'database_cleaner', '~> 1.6', '>= 1.6.2'
  gem 'capybara-screenshot'
  gem 'factory_girl_rails', '~> 4.8'
end

这是我在 Rails 测试控制台中看到的内容并输入

DatabaseCleaner.clean

 => [#<DatabaseCleaner::Base:0x00000005e09368 @orm=:active_record, @strategy=#<DatabaseCleaner::ActiveRecord::Transaction:0x00000005e08f58 @db=:default, @connection_class=ActiveRecord::Base>, @db=:default>] 

我已从自述文件中复制并粘贴了数据库清理器推荐的配置，但它不起作用。 （我将 rspec 与 capybara webkit 一起使用）这是我的完整 rails_helper.rb 文件：

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'
Capybara.javascript_driver = :webkit
Capybara.server = :puma
require 'capybara/rails'
require 'capybara/rspec'
require 'capybara-screenshot/rspec'
require 'capybara/webkit/matchers'
Dir[Rails.root.join("spec/support/**/*.rb")].each { |f| require f }
Capybara.ignore_hidden_elements = false

ActiveRecord::Migration.maintain_test_schema!

RSpec.configure do |config|

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

  config.use_transactional_fixtures = false

  config.before(:suite) do
    if config.use_transactional_fixtures?
      raise(<<-MSG)
        Delete line `config.use_transactional_fixtures = true` from rails_helper.rb
        (or set it to false) to prevent uncommitted transactions being used in
        JavaScript-dependent specs.

        During testing, the app-under-test that the browser driver connects to
        uses a different database connection to the database connection used by
        the spec. The app's database connection would not be able to access
        uncommitted transaction data setup over the spec's database connection.
      MSG
    end
    DatabaseCleaner.clean_with(:truncation)
  end

  config.before(:each) do
    DatabaseCleaner.strategy = :transaction
  end

  config.before(:each, type: :feature) do
    # :rack_test driver's Rack app under test shares database connection
    # with the specs, so continue to use transaction strategy for speed.
    driver_shares_db_connection_with_specs = Capybara.current_driver == :rack_test

    if !driver_shares_db_connection_with_specs
      # Driver is probably for an external browser with an app
      # under test that does *not* share a database connection with the
      # specs, so use truncation strategy.
      DatabaseCleaner.strategy = :truncation
    end
  end

  config.before(:each) do
    DatabaseCleaner.start
  end

  config.append_after(:each) do
    DatabaseCleaner.clean
  end

  config.infer_spec_type_from_file_location!
  config.filter_rails_from_backtrace!
  config.include FactoryGirl::Syntax::Methods
  config.include(Capybara::Webkit::RspecMatchers, :type => :feature)
  config.include Warden::Test::Helpers
  Warden.test_mode!
  config.after :each do
    Warden.test_reset!
  end
end

Capybara::Webkit.configure do |config|
  config.block_unknown_urls
end

RSpec::Matchers.define :appear_before do |later_content|
  match do |earlier_content|
    page.body.index(earlier_content) < page.body.index(later_content)
  end
end

我也参考了本教程并调整了 rspec 配置，但这也无济于事。

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 'database_cleaner'
require 'spec_helper'
require 'rspec/rails'
Capybara.javascript_driver = :webkit
Capybara.server = :puma
require 'capybara/rails'
require 'capybara/rspec'
require 'capybara-screenshot/rspec'
require 'capybara/webkit/matchers'
Dir[Rails.root.join("spec/support/**/*.rb")].each { |f| require f }
Capybara.ignore_hidden_elements = false
Capybara::Screenshot.autosave_on_failure = false

ActiveRecord::Migration.maintain_test_schema!

RSpec.configure do |config|

  config.fixture_path = "#{::Rails.root}/spec/fixtures"
  config.use_transactional_fixtures = false
  config.infer_spec_type_from_file_location!
  config.filter_rails_from_backtrace!
  config.include FactoryGirl::Syntax::Methods
  config.include(Capybara::Webkit::RspecMatchers, :type => :feature)
  config.include Warden::Test::Helpers
  Warden.test_mode!
  config.after :each do
    Warden.test_reset!
  end

  config.before(:suite) do
    DatabaseCleaner.clean_with(:truncation)
  end

  config.before(:each) do
    DatabaseCleaner.strategy = :transaction
  end

  config.before(:each, :js => true) do
    DatabaseCleaner.strategy = :truncation
  end

  config.before(:each) do
    DatabaseCleaner.start
  end

  config.after(:each) do
    DatabaseCleaner.clean
  end
end

Capybara::Webkit.configure do |config|
  config.block_unknown_urls
end

Answer 1

使用数据库清理器自动增加 ID 的行为取决于所使用的特定数据库和您使用的清理方法（截断、删除、事务）。话虽如此，它应该与您的测试无关，因为它们根本不应该依赖于特定的 id。