How do you delete wild card cookies in Rails?

Question

How do you delete a cookie in rails that was set with a wild card domain:

cookies[:foo] = {:value => 'bar', :domain => '.acme.com'}

When, following the docs, you do:

cookies.delete :foo

the logs say

Cookie set: foo=; path=/; expires=Thu, 01 Jan 1970 00:00:00 GMT

Notice that the domain is missing (it seems to use the default params for everything). Respecting the RFC, of course the cookie's still there, Browser -> ctrl/cmd-L ->

javascript:alert(document.cookie);

Voilà!

Q: What's the "correct" way to delete such a cookie?

Answer 1

Pass the :domain on delete as well. Here's the source of that method:

# Removes the cookie on the client machine by setting the value to an empty string
# and setting its expiration date into the past.  Like []=, you can pass in an options
# hash to delete cookies with extra data such as a +path+.
def delete(name, options = {})
  options.stringify_keys!
  set_cookie(options.merge("name" => name.to_s, "value" => "", "expires" => Time.at(0)))
end

As you can see, it just sets a cookie with the name you gave, set to expire in 1969, and with no contents. But it does merge in any other options you give, so you can do:

cookies.delete :foo, :domain => '.acme.com'

And you're set.