Rails 黃瓜斷言測試導致未定義的方法“+”為 nil:NilClass (NoMethodError)

Question

我有一個黃瓜測試項目。 過去的測試成功執行，現在任何使用斷言對象的測試都失敗並在我從控制台運行rake cucumber時出現錯誤

例如我有一個黃瓜測試

Then (/^I should see the Pet Quiz page$/) do
    assert page.current_path == "/pet_quiz/index"
end

我給出了錯誤

 Then I should see the Pet Quiz page    # features/step_definitions/pet_quiz_steps.rb:8
      undefined method `+' for nil:NilClass (NoMethodError)
      ./features/step_definitions/pet_quiz_steps.rb:9:in `/^I should see the Pet Quiz page$/'
      features/pet_quiz.feature:10:in `I should see the Pet Quiz page'

下面是我的 Gemfile，我相信錯誤的來源可能來自其中一顆寶石

source 'https://rubygems.org'
git_source(:github) { |repo| "https://github.com/#{repo}.git" }

ruby '2.5.7'

# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '~> 5.2.4', '>= 5.2.4.4'
# Use sqlite3 as the database for Active Record
#gem 'sqlite3'
# Use Puma as the app server
gem 'puma', '~> 3.11'
# Use SCSS for stylesheets
gem 'sass-rails', '~> 5.0'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'mini_racer', platforms: :ruby

# For accessing environment variables in the app, for API keys
gem 'dotenv-rails'

# Use bootstrap sassc
gem 'bootstrap-sass', '~> 3.4.1'
gem 'sassc-rails', '>= 2.1.0'
gem 'jquery-rails'

#geocoding gem
gem 'geocoder'

# Use CoffeeScript for .coffee assets and views
gem 'coffee-rails', '~> 4.2'
# Turbolinks makes navigating your web application faster. Read more: https://github.com/turbolinks/turbolinks
gem 'turbolinks', '~> 5'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.5'
# Use Redis adapter to run Action Cable in production
# gem 'redis', '~> 4.0'
# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'

# Use ActiveStorage variant
# gem 'mini_magick', '~> 4.8'

# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development

# Reduces boot times through caching; required in config/boot.rb
gem 'bootsnap', '>= 1.1.0', require: false

group :development, :test do
  # Call 'byebug' anywhere in the code to stop execution and get a debugger console
  gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
end

group :development do
  # Access an interactive console on exception pages or by calling 'console' anywhere in the code.
  gem 'web-console', '>= 3.3.0'
  gem 'listen', '>= 3.0.5', '< 3.2'
  # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
  gem 'spring'
  gem 'spring-watcher-listen', '~> 2.0.0'
    # Use sqlite3 as the database for Active Record
  gem 'sqlite3'
  gem 'cucumber-rails', require: false
  
  #Rspec for unit testing
  gem 'rspec-rails', '~> 4.0.1'
  gem 'rails-controller-testing'

end

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'
  gem 'cucumber-rails', require: false
  #use sqlite3 for testing
  gem 'sqlite3'
  
  gem 'database_cleaner'
  
  #Rspec for unit testing
  gem 'rspec-rails', '~> 4.0.1'
  gem 'rails-controller-testing'
end

group :production do
  gem 'pg', '~> 0.21' # for Heroku deployment
  gem 'rails_12factor'
end

# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]


gem 'webdrivers', '~> 4.0', require: false

知道是什么導致了這個錯誤嗎？

Answer 1

看起來它的一些配置問題，而不是gem issue 。

• 首先，你不需要rake ，你可以通過執行cucumber來運行它
• 為什么你的 Gemfile 中同時有capybara和cucumber ？
• 您是否正確安裝了rspec-rails ？ Rspec 測試通過了嗎？
• 我猜你不需要development Gemfile 組中的所有測試 gem

請不要急於一一添加 gem，不要全部從頭開始 - 這將減少錯誤源

此外，也許有幫助 - 來自信號量團隊的簡單設置指南