Better handles constants

Author: myxoh

lib/grape/api.rb

@@ -6,7 +6,8 @@ module Grape
   # should subclass this class in order to build an API.
   class API
     # Class methods that we want to call on the API rather than on the API object
-    NON_OVERRIDABLE = %I[define_singleton_method instance_variable_set inspect class is_a? ! kind_of? respond_to? const_defined? const_missing].freeze
+    NON_OVERRIDABLE = %I[define_singleton_method instance_variable_set inspect class is_a? ! kind_of?
+                         respond_to? const_defined? const_missing parent parent_name name equal? to_s parents].freeze
 
     class << self
       attr_accessor :base_instance, :instances
@@ -48,7 +49,9 @@ def api.inherited(child_api)
       # Alleviates problems with autoloading by tring to search for the constant
       def const_missing(*args)
         if base_instance.const_defined?(*args)
-          base_instance.const_missing(*args)
+          base_instance.const_get(*args)
+        elsif parent && parent.const_defined?(*args)
+          parent.const_get(*args)
         else
           super
         end