我按照Everyday Rails Testing with RSpec一书中的示例创建了一个自定义 RSpec 匹配器，用于重定向到登录页面（requires_login匹配器）。该匹配器的代码如下所示：
RSpec::Matchers.define :require_login do
match do |actual|
redirect_to Rails.application.routes.url_helpers.login_path
end
failure_message_for_should do |actual|
"expected to require login to access the method"
end
failure_message_for_should_not do |actual|
"expected not to require login to access method"
end
description do
"redirect to the login form"
end
end
然后在下面的示例中调用此匹配器：
describe "GET #edit" do
it "requires login" do
user = FactoryGirl.create(:user)
get :edit, id: user
expect(response).to require_login
end
end # End GET #edit
出于某种原因，上述测试有效，而以下测试无效（即使它也检查重定向到登录路径）：
describe "GET #edit" do
it "requires login" do
user = FactoryGirl.create(:user)
get :edit, id: user
expect(response).to redirect_to login_path
end
end # End GET #edit
我已经多次查看我的代码以及上面提到的书中的示例，但找不到任何错误。任何有关如何正确实现此匹配器的见解将不胜感激。我也在使用 Ruby 2.0.0、Rails 3.2.13 和 RSpec-Rails 2.13.1。
解决方案（感谢 Frederick Cheung 的建议）
RSpec::Matchers.define :require_login do |attribute|
match do |actual|
expect(attribute).to redirect_to Rails.application.routes.url_helpers.login_path
end
failure_message_for_should do |actual|
"expected to require login to access the method"
end
failure_message_for_should_not do |actual|
"expected not to require login to access method"
end
description do
"redirect to the login form"
end
end