undefined local variable or method ‘xxx’ for #<RSpec::Core::ExampleGroup::Nested_1::Nested_1:0xbc88d6c>错误解决方案

官方文档如下：

https://github.com/rspec/rspec-rails/blob/master/Capybara.md

Capybara 2.0

To use Capybara 2.0, you need rspec-rails-2.11.1 or greater.

Capybara::DSL is added to examples in:

• spec/features

Capybara::RSpecMatchers is added to examples in:

• spec/features
• spec/controllers
• spec/views
• spec/helpers
• spec/mailers

问题原因：Capybara2.0以后，集成测试的目录变了

解决方案为：默认生成的RSpec集成测试目录为requests目录，改为features目录即可解决问题

参考原文：https://github.com/rspec/rspec-rails/issues/360