Clear token auth cache before specs

We don't want to accidentally leak auth state across the specs. However,
we can't be sure what other information was stored in the cache which
should remain. To be a good Ruby citizen we only clear the cache related
to our auth changes.

We could have kept track of what was added by our mixin. However that is
much more error prone and would require logic to track all the changes.
The simple way to handle this is to just clear all caches which match
our namespace.

Author: cupakromer

lib/kracken/controllers/token_authenticatable.rb

@@ -40,6 +40,10 @@ def cache_valid_auth(token, force: false, &generate_cache)
         shallow_freeze(val)
       end
 
+      def clear_auth_cache
+        Rails.cache.delete_matched TOKEN_AUTH_CACHE_PREFIX + "*"
+      end
+
       def shallow_freeze(val)
         # `nil` is frozen in Ruby 2.2 but not in Ruby 2.1
         return val if val.frozen? || val.nil?

lib/kracken/rspec.rb

@@ -75,6 +75,10 @@ def authenticate_user_with_token!
     c.include Kracken::SpecHelper::Request, type: :kracken
     c.include Kracken::SpecHelper::Request, type: :request
 
+    c.before do
+      Kracken::Controllers::TokenAuthenticatable.clear_auth_cache
+    end
+
     c.before(type: :kracken) do
         Kracken::SpecHelper.current_user = nil
     end