Register endpoint_auth_wrapper middleware only if not yet registered.

Author: texpert

lib/grape-swagger.rb

@@ -32,7 +32,11 @@ def add_swagger_documentation(options = {})
         options = { target_class: self }.merge(options)
         @target_class = options[:target_class]
 
-        use options[:endpoint_auth_wrapper] if !options[:endpoint_auth_wrapper].nil? && options[:endpoint_auth_wrapper].method_defined?(:before)
+        if !options[:endpoint_auth_wrapper].nil? &&
+           options[:endpoint_auth_wrapper].method_defined?(:before) &&
+           !middleware.flatten.include?(options[:endpoint_auth_wrapper])
+          use options[:endpoint_auth_wrapper]
+        end
 
         documentation_class.setup(options)
         mount(documentation_class)