1 files changed, 43 insertions, 2 deletions
diff --git a/lib/api/helpers.rb b/lib/api/helpers.rb
index ce7b7b497fc..054eb2d3f70 100644
--- a/lib/api/helpers.rb
+++ b/lib/api/helpers.rb
@@ -8,7 +8,7 @@ module Gitlab
       if @project ||= current_user.projects.find_by_id(params[:id]) ||
                       current_user.projects.find_by_code(params[:id])
       else
-        error!({'message' => '404 Not found'}, 404)
+        not_found!
       end
 
       @project
@@ -19,7 +19,48 @@ module Gitlab
     end
 
     def authenticate!
-      error!({'message' => '401 Unauthorized'}, 401) unless current_user
+      unauthorized! unless current_user
+    end
+
+    def authorize! action, subject
+      unless abilities.allowed?(current_user, action, subject)
+        forbidden!
+      end
+    end
+
+    # error helpers
+
+    def forbidden!
+      render_api_error!('403 Forbidden', 403)
+    end
+
+    def not_found!(resource = nil)
+      message = ["404"]
+      message << resource if resource
+      message << "Not Found"
+      render_api_error!(message.join(' '), 404)
+    end
+
+    def unauthorized!
+      render_api_error!('401 Unauthorized', 401)
+    end
+
+    def not_allowed!
+      render_api_error!('Method Not Allowed', 405)
+    end
+
+    def render_api_error!(message, status)
+      error!({'message' => message}, status)
+    end
+
+    private 
+
+    def abilities
+      @abilities ||= begin
+                       abilities = Six.new
+                       abilities << Ability
+                       abilities
+                     end
     end
   end
 end