在Rails上运行系统测试时，为什么会出现错误“未定义的方法'期望'？”]

Question

[当我使用rails test:system运行系统测试时，收到以下错误：

Error:
PaymentSessionsTest#test_payment_succesful_if_valid_details_provided:
NoMethodError: undefined method `expect' for #<PaymentSessionsTest:0x00007fffd82485d0>
Did you mean?  exec
    test/system/payment_sessions_test.rb:26:in `block in <class:PaymentSessionsTest>'

背景

我正在编写我的第一个Rails系统测试，并且我的页面加载需要一段时间。建议从Capybara documentation中使用expect方法，例如。 expect(page).to have_current_path(payment_success_url)，它将使用Capybara的等待行为（因此，在页面加载之前测试不会超时）。但是，当我这样做时，会收到上面的错误。

[expect是Capybara还是RSpec的一部分，我有点困惑。它在Capybara的文档中，因此我认为它应该

just work

，但我目前仍处于工作状态。相关源代码

# test\system\payment_sessions_test.rb

require "application_system_test_case"

class PaymentSessionsTest < ApplicationSystemTestCase
  setup do
    @event = events(:one)
  end

  test "payment successful if valid details provided" do
    # Enter payment details on invite page
    visit event_url(@event)
    fill_in "Your name", with: "John Doe"
    fill_in "Email", with: "[email protected]"
    fill_in "Gift amount", with: "20"
    click_on "Pay"

    # Stripe Checkout
    fill_in "cardNumber", with: "4242424242424242"
    fill_in "cardExpiry", with: "01#{Date.today.next_year.strftime("%y")}" # grab year always as next year in 2 digit format
    fill_in "cardCvc", with: "123"
    fill_in "Name on card", with: "Mr John Doe"
    fill_in "billingPostalCode", with: "N1 7GU"
    click_on "Pay"

    # Payment success page
    expect(page).to have_current_path(payment_success_url) # ensure Capybara waits for page to load after clicking Pay
    assert_selector "h1", text: "Payment successful!"
  end

end

# test\application_system_test_case.rb

require "test_helper"

class ApplicationSystemTestCase < ActionDispatch::SystemTestCase
  driven_by :selenium, using: :chrome, screen_size: [1400, 900]
  # driven_by :selenium, using: :headless_chrome

  def setup
    # ensure url helpers use correct host and port for system tests
    Rails.application.routes.default_url_options[:host] = Capybara.current_session.server.host
    Rails.application.routes.default_url_options[:port] = Capybara.current_session.server.port
  end

end

# test\test_helper.rb

ENV['RAILS_ENV'] ||= 'test'
require_relative '../config/environment'
require 'rails/test_help'
require 'bcrypt' # required for devise (used when creating encrypted password for user fixtures)
require 'pry'

class ActiveSupport::TestCase
  include HashidsHelper

  # Setup all fixtures in test/fixtures/*.yml for all tests in alphabetical order.
  fixtures :all

  # Add more helper methods to be used by all tests here...
  include Devise::Test::IntegrationHelpers # include devise test helpers in all tests

  setup do
    # set hashid for each event record
    # NB. can't set using fixtures as event.id is dynamic
    FixMissingHashidsService.run
  end
end

# Gemfile

group :test do
  # Adds support for Capybara system testing and selenium driver
  gem 'capybara', '>= 2.15'
  gem 'selenium-webdriver'
  # Easy installation and use of chromedriver to run system tests with Chrome
  # gem 'chromedriver-helper'
  # Using chromedriver in Windows, added to path, via WSL1
end

使用的详细信息和版本

Rails 5.2.3

通过WSL（1）并使用Windows chromedriver二进制文件运行（Chrome打开并运行测试-其他不使用expect的测试运行正常）

作为测试流程的一部分，在测试中使用Stripe Checkout测试网关（即，它实际上转到checkout.stripe.com/pay/cs_test_etc ...）

[当我使用rails test：system运行系统测试时，收到以下错误：错误：PaymentSessionsTest＃test_payment_succesful_if_valid_details_provided：NoMethodError：未定义的方法'expect'...

Answer 1

Answer 2

Answer 3

Answer 4

require "application_system_test_case"
require "minitest/autorun"                             # new line
require "rspec/expectations/minitest_integration"      # new line
class PaymentSessionsTest < ApplicationSystemTestCase
 setup do
   @event = events(:one)
 end

 test "payment successful if valid details provided" do
   # Enter payment details on invite page
   visit event_url(@event)
   fill_in "Your name", with: "John Doe"
   fill_in "Email", with: "[email protected]"
   fill_in "Gift amount", with: "20"
   click_on "Pay"

   # Stripe Checkout
   fill_in "cardNumber", with: "4242424242424242"
   fill_in "cardExpiry", with: "01#{Date.today.next_year.strftime("%y")}" # 
   grab year always as next year in 2 digit format
   fill_in "cardCvc", with: "123"
   fill_in "Name on card", with: "Mr John Doe"
   fill_in "billingPostalCode", with: "N1 7GU"
   click_on "Pay"

   # Payment success page
   expect(page).to have_current_path(payment_success_url) # ensure Capybara 
   waits for page to load after clicking Pay
   assert_selector "h1", text: "Payment successful!"
 end

end