I know there are dozens of questions on different sites about this issue. I have tried a lot of things, and I still can\'t get the link with DELETE method to work.
I\'ve
in devise.rb
find config.sign_out_via = :delete
change to config.sign_out_via = :get
if you use :get make sure you are using :method = :get and if you are using :delete using :method => :delete in your link
in production you may have to swap it round, so you should use an if statement to check RAILS_ENV
In your example you are probably running in development mode and not test, which is why it's probably not working.
And restart your server as it's an initialiser.