Simplify validation logic inside strategies

CHANGELOG.rdoc

@@ -1,3 +1,6 @@
+* deprecations
+  * Strategy#validate() no longer validates nil resources
+
 == 2.1.0
 
 Notes: https://github.com/plataformatec/devise/wiki/How-to:-upgrade-to-devise-2.1

lib/devise/strategies/authenticatable.rb

@@ -18,13 +18,24 @@ module Devise
 
     private
 
-      # Simply invokes valid_for_authentication? with the given block and deal with the result.
+      # Receives a resource and check if it is valid by calling valid_for_authentication?
+      # An optional block that will be triggered while validating can be optionally
+      # given as parameter. Check Devise::Models::Authenticable.valid_for_authentication?
+      # for more information.
+      #
+      # In case the resource can't be validated, it will fail with the given
+      # unauthenticated_message.
       def validate(resource, &block)
+        unless resource
+          ActiveSupport::Depreation.warn "an empty resource was given to #{self.class.name}#validate. " \
+            "Please ensure the resource is not nil", caller
+        end
+
         result = resource && resource.valid_for_authentication?(&block)
 
         case result
         when Symbol, String
-          ActiveSupport::Deprecation.warn "valid_for_authentication should return a boolean value"
+          ActiveSupport::Deprecation.warn "valid_for_authentication? should return a boolean value"
           fail!(result)
           return false
         end

lib/devise/strategies/database_authenticatable.rb

@@ -6,12 +6,11 @@ module Devise
     class DatabaseAuthenticatable < Authenticatable
       def authenticate!
         resource = valid_password? && mapping.to.find_for_database_authentication(authentication_hash)
+        return fail(:invalid) unless resource
 
         if validate(resource){ resource.valid_password?(password) }
           resource.after_database_authentication
           success!(resource)
-        elsif !halted?
-          fail(:invalid)
         end
       end
     end

lib/devise/strategies/rememberable.rb

@@ -19,11 +19,13 @@ module Devise
       def authenticate!
         resource = mapping.to.serialize_from_cookie(*remember_cookie)
 
+        unless resource
+          cookies.delete(remember_key)
+          return pass
+        end
+
         if validate(resource)
           success!(resource)
-        elsif !halted?
-          cookies.delete(remember_key)
-          pass
         end
       end
 

lib/devise/strategies/token_authenticatable.rb

@@ -16,12 +16,11 @@ module Devise
 
       def authenticate!
         resource = mapping.to.find_for_token_authentication(authentication_hash)
+        return fail(:invalid_token) unless resource
 
         if validate(resource)
           resource.after_token_authentication
           success!(resource)
-        elsif !halted?
-          fail(:invalid_token)
         end
       end