Testing alias of link_to on Rails 1.2.6

[captaffy]

I’m trying to write a test for an alias of link_to on Rails 1.2.6, but
it’s always loading:
vendor/gems/ruby/1.8/gems/actionpack-1.13.6/lib/action_view/helpers/url_helper.rb:67

instead of my version, written in a plugin.

Any ideas?