Capybara is confusing me. If I use Capybara in combination with Ruby on Rails 3 and RSpec 2, then in RSpec request tests, the following matcher works:
respon
So I just ran into similar, and this is I think what's going on:
It depends on code you didn't include here of how you visit the page. I'm writing an rspec request spec.
If I retrieve the page with rspec's own:
get '/some/path'
then response.body.should have_selector works as you say, but page.should does not.
To make Capybara 'page' work (and to make Capybara interactions like click_button or fill_in work), instead of retrieving with rspec's 'get', you need to retrieve with Capybara's 'visit':
visit '/some/path'
page.should have_selector("works")
'page', a capybara method, only gets set when using 'visit', a capybara method.
This does get confusing, all the mixing and matching of different libraries involved in rails testing.
You would use response
when you want to use the standard rails methods. And, alternately, you'd use page
when you want to use the capybara methods. In capybara you'd most likely use have_css
in the example given.